Review ArticleOrganocatalysis Key Trends in Green Synthetic ChemistryChallenges Scope towards Heterogenization and Importancefrom Research and Industrial Point of View

Isak Rajjak Shaikh123

1 Department of Chemistry Shri Jagdishprasad Jhabarmal Tibrewala University Vidyanagari Jhunjhunu-Churu RoadChudela Jhunjhunu District Rajasthan 333001 India

2 Razak Institution of Skills Education and Research (RISER) Shrinagar Near Rafaiya Masjid and Hanuman MandirNanded Maharashtra State 431 605 India

3 Post Graduate and Research Centre Department of Chemistry Poona College of Arts Science and Commerce Camp AreaPune 411 001 Maharashtra State India

Correspondence should be addressed to Isak Rajjak Shaikh isakindiacom

Received 26 September 2013 Revised 17 December 2013 Accepted 23 December 2013 Published 26 March 2014

Academic Editor Sankaranarayana Pillai Shylesh

Copyright copy 2014 Isak Rajjak Shaikh This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

This paper purports to review catalysis particularly the organocatalysis and its origin key trends challenges examples scopeand importanceThe definition of organocatalyst corresponds to a lowmolecular weight organic molecule which in stoichiometricamounts catalyzes a chemical reaction In this review the use of the term heterogenized organocatalystwill be exclusively confined toa catalytic system containing an organicmolecule immobilized onto some sort of supportmaterial and is responsible for acceleratinga chemical reaction Firstly a brief description of the field is provided putting it in a green and sustainable perspective of chemistryNext research findings on the use of organocatalysts on various inorganic supports including nano(porous)materials nanoparticlessilica and zeolitezeolitic materials are scrutinized in brief Then future scope research directions and academic and industrialapplications will be outlined A succinct account will summarize some of the research and developments in the field This reviewtries to bring many outstanding researches together and shows the vitality of the organocatalysis through several aspects

1 Introduction

In 1987 theUnitedNationsCommission onEnvironment andDevelopment (BrundtlandCommission) [1] defined ldquosustain-able developmentrdquo as the development that meets the needsof the present without compromising the ability of futuregenerations to meet their own needs Two of the key aspectsof sustainable development from an energy and chemicalperspective are to develop more renewable forms of energyand to reduce pollution Chemistry during the twentiethcentury changed the living standard of humanbeings Amongthe greatest achievements of chemistry are petrochemicaland pharmaceutical industries But these industries are oftenblamed for polluting environment The challenge for the

present-day chemical industry is to continue providing appli-cations and socioeconomic benefits in an environmentallyfriendly manner

Over the last few decades green chemistry has beenrecognized as a culture and methodology for achieving sus-tainable development [2] Green chemistry is chemistry ableto promote innovative technologies that reduce or eliminatethe use or generation of hazardous substances Anastas andWarner defined the 12 principles of green chemistry (Figure 1)[3] Catalysis (including enzyme catalysis heterogeneouscatalysis and organocatalysis in particular) is identified to beat the heart of greening of chemistry [4] because this branchof science is found to reduce the environmental impact ofchemical processes [5]

Hindawi Publishing CorporationJournal of CatalystsVolume 2014 Article ID 402860 35 pageshttpdxdoiorg1011552014402860

2 Journal of Catalysts

(1) P

reve

nt w

aste

(2) M

axim

ize a

tom

econ

omy

(3) L

ess h

azar

dous

chem

ical

synt

hesis

(4) Safer chemicals and products

(5) Safety solvents and reaction conditions

(6) Increase energy efficiency

(7) U

se re

new

able

feed

stock

s

(8) A

void

chem

ical

der

ivat

ives

(pro

tect

ing

grou

ps)

(9) U

se ca

taly

sts

(10) Design chemicalsand products to degrade after use

(11) Analyze in real timeto prevent pollution

(12) Minimize potentialfor accidents

Figure 1 Inspired by the 12 principles of green chemistry from [3]

2 Catalysis A MultidisciplinaryArea of Chemistry

Catalyst is one of the few conceptual words that havecarried over broadly outside scientific language Catalysis isa significant multidisciplinary area of chemistry The termldquocatalysisrdquo was first introduced in 1836 by Berzelius whotried to explain special powers of some chemical substancescapable of influencing various decomposition and chemicaltransformations

According to Ostwald [6] ldquoa catalyst accelerates a chemi-cal reaction without affecting the position of the equilibriumrdquoA catalyst works by interacting with reactants generatingintermediates that react to give products It affects the rate ofapproach to equilibrium of a reaction but not the position ofthe equilibrium (Figure 2) Most of the times it also providessubtle control of chemical conversions increasing the rate ofa desired reaction pathway but not the rates of undesired sidereactions (ie the selectivity of a chemical process)

Catalysts are usually classified according to structurecomposition area of application or state of aggregation

Reaction coordinate

Transition state

Catalysis

Ener

gy

C + DA + B

Ea

Figure 2 Schematic illustration of the effect of a catalyst on thetransformation of A + B into C + D

Journal of Catalysts 3

According to the state of aggregation in which the catalystsact there are two main groups homogeneous catalysts andheterogeneous catalysts Homogeneous catalysts are well-defined chemical compounds or coordination complexeswhich together with the reactants are molecularly dispersedin the reaction medium and carry out processes in a uniformgas or liquid phase Heterogeneous catalysis takes placebetween different phases Generally the catalyst is in solidstate and the reactants are gases or liquids The immobilizedcatalysts obtained by attaching homogeneous catalysts tosolid are in between In supported catalysts the catalyticallyactive substance is applied to a support material that hasa large surface area and is usually porous Arguments forand against shall always be made while discussing the meritsand limitations of individual groups of catalysts for theirrespective applications in industries

3 Application of Catalysis

Catalysis has played a pivotal role in the success of thechemistry industry in the twentieth century More than 90of chemical manufacturing processes in the world utilizecatalysts [7 8] Historically the first industrially appliedcatalytic process was for the hydrogenation of oils and fatsto produce margarine using finely divided nickel as catalystThus heterogeneous catalysis was applied first industriallyThe issue of metal leaching and the avoidance of tracecatalyst residues are very important from environmentalhealth point of view All the basic raw materials or buildingblocks for chemicals are manufactured by very important setof heterogeneous catalytic reactions (Table 1) [8] Althoughcatalysts are not consumed by the reaction itself they may beinhibited deactivated or destroyed by secondary processesThe solid-state catalyticmaterials are themost important typeof catalysts

Implementation of ldquocleanrdquo and ldquogreenrdquo chemical technol-ogy in industries may help address the problem of envi-ronmental degradation besides producing useful chemicals[9ndash12] Some catalysts also present important technology inthe prevention of emissions for example catalytic converterfor automobiles Keeping in mind the fragile ecosystem andthe importance of preserving the environment the hetero-geneous catalysts are tested in the pollution abatement [1314] and to remove aqueous organic wastes volatile organiccompound and vehicular primary emissions such as COunburned hydrocarbon NOx and soot

Heterogeneous catalysis which takes place between dif-ferent phases has now grown into an important branch ofscience [8ndash12 15] Exciting new opportunities are emergingin this field based on nanotechnology approaches Henceresearch efforts are being directed to develop chemistry ofnanomaterials and their applications in catalysis for devel-oping cost-effective selective energy sufficient ecofriendlyand environmentally benign synthetic processes for indus-tries Though this involves a great scientific economic andtechnological challenge it is essential to a sustainable andhealthy way of life

The petroleum and fine chemical and pharmaceuticalindustries mostly rely on catalysts to produce everything

from natural gasfuels to various commodities [15 16] Thereare a variety of new challenges in creating alternative fuelsreducing harmful by-products in manufacturing cleaningup the environment and preventing future pollution deal-ing with the causes of global warming and creating safechemicals and pharmaceuticals Thus catalysts are needed tomeet these challenges of health safety and environmentalenergy-related and economic issues but their complexityand diversity demand an insight on the way catalysts arestudied designed and used This could come into realityonly through the application of an interdisciplinary approachinvolving new methods for synthesizing and characteriz-ing molecular and material systems Research in heteroge-neous catalysis demands the cooperation of scientists fromanalytical chemistry solid-state chemistry (nano)materialschemistry physical chemistry surface science computationaland theoretical chemistry reaction kinetics and mecha-nisms reaction engineering and so forth Opportunities tounderstand and predict how catalysts work at the atomicscale are now appearing made possible by breakthroughsin the last decade in computation measurement techniquescharacterization spectroscopy and imaging and especiallyby new developments in surface-reactivity studies modelcatalyst design and evaluation [16 17] Surface science andspectroscopy has its prominent role in analysing surfacereaction chemistry on the catalyst [18 19]

Fermentation of sugar to ethanol and the conversionof ethanol to acetic acid catalyzed by enzymes were anexample of catalysis in antiquity Off late enzymatic catalysisis considered as a separate branch of (biological) catalysis It isthe most recent branch widely included in many commercialapplications [20 21] Enzymes are also highly active undermild conditions such as temperature pressure and pHwhichmake them easier to work with on a small scale but are alsomore appealing on an industrial scale on a cost and efficiencybasis Another benefit is that reactions are preferentiallycarried out in aqueous media therefore providing a ldquogreenerrdquoroute Not to forget the development of water based organictransformations is also an area of rapidly growing importancein chemistry [22 23]

The homogeneous catalysis prior to the recognition ofthe effects of heterogeneous catalysts started with the actionof nitrous oxides in the lead chamber process Althoughthe fundamental processes for refining petroleum and itsconversion to basic building blocks are based on heteroge-neous catalysts many important value-added products aremanufactured by homogeneous catalytic processes (Table 2)[12] Homogeneous catalysts have been well researchedsince their catalytic centers can be relatively easily definedand understood but difficulties in separation and catalystregeneration prevent their wider use [12 24ndash28] The mostwidely used homogeneous catalysts are simple acids orbases which catalyze well-known reactions such as esterand amide hydrolysis or esterification The market share ofhomogeneous catalysts is estimated to be only ca 10ndash15Many of the benefits of homogeneous catalysts especiallyhigh selectivity arise from tailored made catalysts involvingtransition metals (or lanthanides) and appropriate ligandsSuch catalysts are inexpensive enough that they can be

4 Journal of Catalysts

Table 1 List of some of the industrially applied reactions and catalysts

Reaction Catalyst Inventor (Year)Sulphuric acid (leadmdashchamber process) NO

119909Clement Desormes (1806)

Chlorine production by HCl oxidation CuSO4 Deacon (1867)Nitric acid by NH3 oxidation Pt Rh nets Ostwald (1906)Fat hardening Ni Normann (1907)

Ammonia synthesis (H2 + N2) Fe Mittach Haber Bosch (1908)Production 1913 BASF

Hydrogenation of coal to hydrocarbons Fe Mo Sn Bergius (1913) Pier (1927)Methanol synthesis from CoH2 ZnoCr2O3 Mittach (1923)Hydrocarbons from COH2 (motor fuels) Fe Co Ni Fischer Tropsch (1925)Alkylation of olefins to gasoline AlCl3 Pines (1932)Cracking of hydrocarbons Al2O3SiO2 Houdry (1937)Cracking in a fluidized bed Aluminosilicates Lewis Gilliland (1939)Ethylene polymerization at low pressure Ti compounds Ziegler Natta (1954)Hydrogenation isomerization hydroformylation Rh- Ru complexes Wilkinson (1964)

Methanol carbonylation to acetic acidCoiodide BASF (1960)Rhiodide Monsanto Co (1966)Iridium BP Chemicals Ltd (2000)

Asymmetric hydrogenation Rhchiral phosphine Knowles (1974)Three-way catalyst Pt Rhmonolith General Motors (1974)Methanol conversion to hydrocarbons Zeolites Mobil Chemical Co (1975)Alpha-olefins from ethylene Nichelate phosphine Shell company (1977)Sharpless (epi) oxidation TIROOHTartarate May Baker Upjohn ARCO (1981)Selective oxidations with H2O2 TS-1 (titanium silicate) Enichem (1983)Hydroformylation Rhphosphine Rhone-Poulene-Ruhrchemie (1984)Polymerization of olefins ZirconoceneMAO Sinn Kaminsky (1985)Selective catalytic reduction (SCR) V W Ti oxidesmonolith 1986

Table 2 Differences between homogeneous catalysts and heteroge-neous catalysts

Homogeneous catalysts Heterogeneous catalystsSame phase as reaction medium Solid phaseDifficult separation Easily separableNo recyclability Recyclability and regenerationOften high rates of reaction Low rates of reactionNo diffusion control Diffusion controlRobust to poisoning Poisoning deactivationHigh selectivity Low selectivityShort life Long catalytic lifeMild conditions Energy-consuming processWell understood mechanism Poor mechanistic understanding

neutralized easily separated from organic materials anddisposed of This contributes to the huge quantity of aqueoussalt waste generated by industry Organometallic catalysts arecurrently widely used in industry but the search for improvedefficiencies enantioselectivities or recycling is still a matterof intense researches [29ndash33] It is true that homogeneouslycatalyzed processes such as hydroformylation carbonylationoxidation hydrogenation metathesis and hydrocyanationcontribute with millions of tons to the bulk chemicals but

on the other hand the progress of homogeneous catalysisis also going on with fine chemicals [25 33] In spirit ofthat the beginning of this century saw the renaissance oforganocatalysis presenting an environmental advantage overmetal based catalysts for stereoselective or asymmetric syn-thetic methodologiesThe absence of metal in organocatalystbrings an undeniable advantage considering the principles ofldquogreen chemistryrdquo and the economic point of view (Tables 3and 4)

Understanding catalytic systems involve study of struc-ture state and composition of catalysts and the phase inwhich they perform And for this one needs to understandchemistry of molecules and materials useful as catalysts andor catalyst carriers

4 Materials for Catalysis

The diversity of research field connected to the chemistry ofmaterials is significant for their applications in many areasincluding adsorption catalysis electrochemistry and surfacescience Nanoparticles [34] metal oxide and mixed metaloxides [35ndash38] prepared by simple methods are useful cata-lysts Research involving metal-organic frameworks [39 40]mesoporous silica [41ndash43] microporous or open-frameworkinorganic [44ndash46] andor mesopore modified [47] materials

Journal of Catalysts 5

Table 3 Comparison among organometallic catalysts enzyme catalysts and organocatalysts

Organometallic catalyst Enzyme catalyst Organocatalyst

Wide substrate scope high catalyticactivity involving tedious processpotential heavy metal pollution

Limited substrate scope highselectivity and catalytic activity

usually single enantiomer

Robust inexpensive readily available nontoxic inert towardmoisture and oxygen method especially attractive for the

preparation of compound that do not tolerate metal contamination(pharmaceutical products)

Table 4 Advantages and disadvantages of organocatalysts

Advantages DisadvantagesEasy preparation or availability High catalyst loadingEasy handling inert towards moisture(water) and air (oxygen) Relatively premature field

Easy scale-upNo metal contaminationEasy screeningUseful in complex (steric) reactions

has steadily increased following the widespread utility ofaluminosilicate zeolites [48ndash51] titanosilicates [52 53] andaluminium phosphates [54 55]

In industries research endeavours are mainly devotedtowards the study and development of zeolites or zeoliticmaterials with several attractive features such as cat-alytic active site(s) large surface area zeolitic pore wallsand pore size control The synthesis and characteriza-tion of the crystalline aluminosilicate materials with tun-able meso-microporosity and their strong acidity havepotentially important technological implications for shape-selective catalytic reactions ion exchange and adsorption oforganic compounds [56ndash58]Thepore diameters can be finelychosen tuned and utilized for exhibiting shape-selectivecatalysis depending on the molecular shapesize of organicreactant and product The widespread interest has beendeveloped in the zeolitic science towards the developmentand discovery of zeolites with desired characteristics sinceconventional zeolites lack fine tuning of their properties toacidbase and redox or bifunctional or multifunctional prop-erties Organic functionalization adds new catalytic functionsto zeolites [59]

Zeolites are microporous crystalline aluminosilicateswith unique properties used for many processes Zeolitespossess acid sites that are associated with the tetrahedralaluminium atoms in their framework and therefore theamount of acidity depends on the aluminium content ofthe zeolite Zeolite acid catalysts have wide application inindustrial processesThe introduction of Y-zeolites to replaceamorphous silica-alumina in fluidized catalytic cracking(FCC) and in hydrocracking processes in the early 1960rsquos wasa breakthrough application in acid catalysis With the everincreasing research efforts in this area leading to discoveriesof new structures and modification schemes by academicand industrial laboratories the potential of solid acids hasevolved tremendously However with the exception of theZSM-5 Mordenite and to some extent Beta zeolite very few

of these structures have been applied in industrial processesto any significant extent Yet one can account for relativelyfew applications to the huge number of new materialsintroduced Notable examples are the reported uses of SAPOsin lube dewaxing and in natural gas to olefin technologiesand MCM-22 in aromatics alkylation The zeolite structureswith large-porebimodal porosity and tunable acidity canbe a remarkable benefit for catalytic processes in industriesWithin industrial catalysis there are constant innovation andchanging approaches to provision of selective economicallyviable and environmentally benign processes

Recently enormous growth in the chemical diversity ofinorganic materials with transition-metal incorporation innew compositional domains has also been explored dueto their potential application in adsorption and catalysisInorganic polymers transition metal phosphates and metal-organic frameworks [39 40] with novel catalytic electronicmagnetic and unique structural properties are particularlypromising candidates [60ndash64] The mesoporous structurewith strong acidity can be a remarkable benefit for catalyticreactions involving large organic molecules in which diffu-sion constraints andor adsorption of reactantmolecules ontothe strong acid sites are the main concern A lot has beenreported about the pathways to developmesostructured silica[65] In terms of surface functionalization the performanceof mesoporous silica has been polished by several methodssuch as metal incorporation [66] metal deposition [67]grafting by organic functional groups [68] and immobiliz-ing metal complex [69] New approaches to synthesis andcharacterization of bimodal that is micro-mesoporous andor meso-macroporous materials might assist us in under-standing the phenomena of diffusion confinement effectsselectivity and so forth [47]

5 Organocatalysis A NovelSynthetic Philosophy

The term ldquoorganocatalystrdquo is a concatenation of the wordsldquoorganicrdquo and ldquocatalystrdquo The definition corresponds to a lowmolecular weight organicmolecule which in substoichiomet-ric amounts catalyzes a chemical reactionThe organocatalystcould be achiral or chiral and could be composed of CH N S and P Organocatalysis has several advantages notonly because of its synthetic range but also for the economicreasons The absence of metal in organocatalyst brings anundeniable advantage considering both the principles ofldquogreen chemistryrdquo and the economic point of view (Figure 3)

Nowadays organocatalysis is one of the hot researchtopics in advanced organic chemistry It is a novel syn-thetic philosophy and mostly an alternative to the prevalent

6 Journal of Catalysts

N

H

L-ProlineN

N

DMAP

OH

Nobin

N

NO

H

MacMillanrsquos catalyst

O

N

HO N

Quinine

CO2H

NH2

∙ ∙

Figure 3 Few famous examples of organocatalysts L-proline DMAP quinine and MacMillanrsquos catalyst

transition metal catalysis Organocatalysts are often basedon nontoxic organic compounds originating from biologicalmaterials Organocatalysts can be Lewis bases Lewis acidsBroslashnsted bases and Broslashnsted acids Most of the organocatal-ysis reported so far are explained by Lewis base mechanismThe Lewis base mechanism can be simplified as follows

Step I Lewis base for example cinchona alkaloidinitiates catalysis via a nucleophilic addition to ordeprotonation of the substrateStep II the chiral intermediate undergoes reactionStep III separation of product(s) from the catalystoccursStep IV regeneration of the catalyst and its availabilityfor a new catalytic cycle occurs

There are many organocatalytic reactions that need a secondmechanism to explain the catalytic cycle involved This iscalled bifunctional organocatalysis in which the organocata-lyst possesses not only a Lewis base (nitrogen or phosphorusatom) but also a Broslashnsted acidic site There is a lot to be donein redox catalysis and in exploitation of the synergetic effect ofdifferent catalytic active sites within one organic compoundor material

Some advantages of organocatalysts include the following

(i) Reactions performed by organocatalysts have poten-tial application in large scale production in industries

(ii) Scope organic reactions occur which are not inpractice and not possible by other forms of catalystsfor example asymmetric synthetic processes

(iii) PriceAvailability Low cost alkaloids natural aminoacids L-proline tartaric acid and so forth are easilyavailable and are economically attractive

(iv) Recycling issues immobilization of the catalyst is thesimplest way to recover it

(v) Some of the examples include bioderived andbiodegradable organocatalysts

(vi) Organocatalysts work at mild reaction conditions(vii) Sometimes the final products of reactions contain

high levels of metal contamination derived from cat-alyst degradation phenomena which pose a seriousdrawback if the metal is toxic for pharmaceutical andfood industries Absence of transition-metal bringsorganocatalysis at the heart of greening chemistry

Organocatalysis can be categorized into our different typesas follows

Type-I activation of the reaction based on the nucle-ophilicelectrophilic properties of the catalyst is done(Scheme 1)

Type-II organic molecules form reactive intermedi-ates The chiral catalyst is consumed in the reactionand requires regeneration in parallel catalytic cycle asit is reported in Scheme 2

Type-III phase transfer reactions occur The chiralcatalyst forms a host-guest complexwith the substrateand shuttles between the standard organic solvent anda second phase

Journal of Catalysts 7

O

O

O

O

OOH

100

N

H

3mol L-proline

DMF 20∘C 20h

CO2H

Scheme 1 Hajos and Parrish [70]

O

O

OOO

O

O

30mol catalyst

30 H2O2 (3 equivalent)

CH3CNndashK2CO3

R1R3

R2

R1R3

R2

Scheme 2 Shu and Shi [71]

Catalytic enantioselective enolate alkylation(Scheme 3) occurs

Type-IV molecular-cavity-accelerated asymmetrictransformations occur in which the catalyst mayselect from competing substrates depending on sizeand structure criteria (Scheme 4)

6 Discovery and the History ofOrganocatalysis

Liebigrsquos synthesis of oxamide from dicyan and water is thefirst organocatalytic reaction reported [74] Acetaldehydewasfurther identified to behave as the then-named ldquofermentrdquonow called as enzyme Dakin in 1909 demonstrated that ina Knoevenagel type condensation between aldehydes andcarboxylic acids or esters with active methylene groups theamine catalysts could be mediated by amino acids [75]Langenbeck is remembered for developing enamine typereactions and the application of simple amino acids andsmall oligopeptides as catalysts [76ndash78] Natural products inparticular strychnine brucine and cinchona alkaloids andamino acids (including short oligopeptides) were amongthe first organic catalysts tested [79 80] Though the fieldof small-molecule catalysts seems very simple there are

evidences that prove their pivotal role in synthesis of buildingblocks for life L-Alanine andL-isovaline capable of catalyzingcertain CndashC bond formation reactions had been found onmeteorites [81]

An asymmetric transformation with an organic moleculewas published in 1912 by Bredig and Fiske [82] Pracejusapplied cinchona alkaloids in the asymmetric conversionof ketenes to (S)-methyl hydratropate [83 84] An initialresearch byYamadaampOtaniwas important too [85]The sev-enties brought anothermilestone Hajos and Parrish reporteda L-proline catalyzed Robinson annulation in excellent enan-tioselectivities [70 86 87] Eder et al reported organocat-alytic aldol reactions in good enantioselectivities [88] Tosummarize in 1970s Hajos and Parrish and independentlyEder Sauer and Wiechert published a series of papers andpatents involving such organocatalytic transformations Theasymmetric synthesis of enediones useful building blocksin natural product total syntheses was achieved (S)-Prolineinduced the formation of (S)-enediones

Two mechanisms [89] were proposed (1) involving theformation of a carbinolamine intermediate followed by thedisplacement of the proline moiety by nucleophilic attackof the enol from the side chain ketone (2) involving anenaminium intermediate acting as a nucleophile in the CndashCbond formation with concomitant NHsdot sdot sdotO hydrogen trans-fer Wynberg firstly published various 12 and 14 additionscatalyzed by cinchona bifunctional organocatalysis [90ndash92]

8 Journal of Catalysts

N

O

Ph

Ph

Ph

Ph

N

O

OO

O

81 96 eeO

O

O

O

H N

Chiral quaternary ammonium catalyst10mol catalyst

CH2Cl2BrH2C

Ot-Bu

Ot-Buminus78

∘C 24h

+

Brminus

CsOHmiddotH2O

Scheme 3 Corey et al [72]

O

BOCHN BOCHN

OO OH

Nu

OH

(2) Nu

(1) Polymer

HO

N

HN

HO

O

O

OH

NO2

NO2

+

Scheme 4 Sellergren et al [73]

All these research endeavours were not carefully looked intotill List et al reported in 2000 proline catalyzed aldol reactionin good enantiomeric excesses [93 94]

Asymmetric catalysis constitutes one of the most impor-tant subjects in synthetic organic chemistry Asymmetricsynthesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the application of such methodologies inchemical industry is rather limited due to the high cost ofchiral ligands and noble metals used in such transformationsMoreover the pharmaceutical entities and food industryproducts do not tolerate a contamination of even traces ofany such metals for that matter Synthesis of chiral drugshas a major financial impact in pharmaceutical industrieson a global scale Different enantiomers or diastereomers ofa molecule often have different biological activity Most ofthe drugs might be soon sold as single enantiomers in thecoming years There is a huge demand for organocatalystsleading to 100 yield 100 ee of the desired product Theneed from chemical industry especially pharmaceutical forreliable asymmetric transformations of molecular skeletonsis higher than ever Therefore asymmetric organocatalysisis in a process of attaining maturity into a very powerful

practical and broadly applicable methodological approach inthe catalytic asymmetric synthesis

7 Some Examples and Developments inCatalyst Structural Variants

Following are the famous examples of organocatalysts

71 Proline and Derivatives The proline catalyzed Robinsonannulation was one of the earliest examples of an enantios-elective reaction using an organic catalyst [85] This aminoacid contains both a nucleophilic secondary amino groupand a carboxylic acid moiety functioning as a Broslashnstedacid The availability of proline in both enantiomeric formsbrings advantages over enzymatic methods Arguably thefirst example of proline catalyzed asymmetric aldol reactionis reported by Hajos and Parrish [70 86 87] The Wieland-Miescher ketone is a useful synthetic building block forwhich a classical asymmetric procedure using (S)-prolinewas published forty years ago [88] It is quite significant thatthe first efficient organocatalyzed asymmetric reactions weredescribed by Hajos amp Parrish [86 87] and by Eder et al [88]

Journal of Catalysts 9

both teams from pharmaceutical companies (Hoffmann-la-Roche and Schering) The asymmetric synthesis of theWieland-Miescher ketone is also based on proline andanother early application was one of the transformations inthe total synthesis of erythromycin by Woodward et al [95]Proline is recognized as a versatile organocatalyst of thesetimes (Scheme 5)

In fact the renewal of proline catalyzed transformationsin early 2000 by D W C MacMillan Carlos F Barbas IIIand Benjamin List saw the renaissance of the concept and itwas the starting point of the word ldquoorganocatalysisrdquo ProfessorAhrendt group reported the first enantioselective organocat-alytic Diels-Alder reaction [96] Proline was identified asan effective organocatalyst for asymmetric aldol reaction[97] The catalytic asymmetric 120572-alkylation of aldehydeswas reported by Vignola and List [98] This transformationhad been accomplished with the help of covalently attachedauxiliaries 120572-Methyl L-proline exhibits higher enantioselec-tivities and improved reaction rates when compared to L-proline In recent years proline especially L-proline hasbeen used to catalyze essential transformations used in thefine chemical and pharmaceutical industries such as thedirect asymmetric aldol reactions [99ndash107] Diels-Alder reac-tions Michael reactions [108ndash115] Mannich reaction [116ndash122] Multicomponent reactions [123 124] and 120572-amination[125] 120572-aminoxylation [126ndash128] 120572-oxyaldehyde dimer-ization [100] 120572-functionalization of carbonyl compounds[129] and 120572-alkylation of aldehydes [130] Organocat-alytic cyclopropanation reactions were typically performedusing catalyst-bound ylides However Kunz and MacMil-lan demonstrated that activation of olefin substrates usingcatalytic (S)-(minus)-indoline-2-carboxylic acid is a viable routefor the formation of highly enantioenriched cyclopropanes[131]

Prof K A Joslashrgensen has made an importantbreakthrough in asymmetric synthesis by developing (R)-and (S)-120572120572-bis[35-bis(trifluoromethyl)phenyl]-2-pyrroli-dinemethanol trimethylsilyl ether as excellent chiral organ-ocatalysts in the direct organocatalytic 120572-functionaliza-tion of aldehydes Diarylprolinol silyl ether reagents werefound to catalyze CndashC CndashN CndashO CndashS and CndashHal bondforming reactions [132ndash138] Cascade or domino reactionsswiftly construct complex biologically important compoundsand minimize waste and also the laboratory operations [139]Endersrsquo group developed proline derived organocatalyst fora chemo- diastereo- and enantioselective three-componentdomino reaction to yield tetrasubstituted cyclohexenecarbaldehydes [140] The four stereogenic centers aregenerated in three consecutive CndashC bond formations thatis MichaelMichaelaldol condensation with high diastereo-and complete enantiocontrolThe synthesis of polyfunctionalcyclohexene building blocks involving proline catalytic stepsis reported in this domino reaction

Though this segment of our review is dedicated to prolineas an important class of organocatalysts it would also be agood place to acknowledge the research contributions fromprofessor Ahrendt et al to the field of organocatalysis [96 99100 103 127 131 141ndash150]

Heterogenized Proline An explosion of research articles inthe area of homogeneous organocatalysis occurredwithin thelast decade or so In addition to the initial proline catalyzedreactions the word ldquoorganocatalysisrdquo covers nowadays manyotherwell-knownorganocatalysts and organic reactions Pro-line immobilized onto some sort of inorganic support pavesthe way towards heterogenization of other organocatalysts[151ndash153] A simple and efficient synthesis of polystyrene-supported proline and prolinamide is reported Polystyrene-supported proline catalyzes the asymmetric aldol reactionbetween cyclohexanone and substituted benzaldehydes inwater High yields diastereoselectivities and ee values havebeen observedThe versatility of this resinwas also confirmedby selenenylation of aldehydes Both proline and prolinamideresins gave high yields Recycling studies showed that theproline resin performs as better heterogeneous organocat-alyst as compared to the prolinamide resin [153] An aldolreaction catalyzed by proline functionalized silica gel wasinvestigated in continuous flow microreactors by reaction-progress kinetic analysis and nonlinear chromatography[154]

Though the research community advocates asymmetricsynthesis for industrial application organocatalysts havebeen seldom applied in industry due to insufficient efficiencyand the difficulties in catalyst separation and recycling[155ndash161] The concept of heterogenizing organocatalyst onsupports combines the advantages of both homogeneousorganocatalysis and heterogeneous recycling Though thismight seem simple and present opportunities in indus-trial chemical processes the research in heterogeneousorganocatalysis demands a multidisciplinary approach byidentifying catalytic activity upon bonding organocatalystcovalently to the support understanding noncovalent inter-action as structure-reactivity and conformation decidingfactor taking into consideration the characteristic propertiesof the supports confinement effects if any and so forthSome recent examples will be described on the applicationsof supported proline as organocatalysts for their preindus-trialization study The latter half of this review in generalirons out the detailed discussion on key trendswith examplesscope challenges and ldquogreenrdquo applications of heterogeneousorganocatalysts

72 Other Amino Acids Barbas and coworkers found theproteinogenic amino acid tryptophan (Figure 4) to be anexcellent organocatalyst for the Mannich reaction of hydrox-yacetone with a variety of imines performed in DMF leadingthe desired anti-amino alcohols in excellent diastereoselec-tivities (up to gt19 1) and enantioselectivities (90ndash98 ee)Similarly t-butyl protected threonine catalyzed the aldolreaction of hydroxyacetone and various aldehydes in NMP togive the corresponding syn-aldol adducts in high yields andgood to excellent enantio- and diastereoselectivities [162]Zhao et al reported [163] the development of an aminoacid based small molecule capable of promoting asymmetricmonosilylation of meso-12-diols Furthermore the catalystcan be recycled with equal efficiency Three-componentreaction involving condensation of aldehyde 13-carbonyl

10 Journal of Catalysts

NH

OH

OH

O

O NHPh

O PhH

H

ON

NH

H

O OH

CO2BnCO2Bn

NO2

R1 R2

Scheme 5

NH

OH

O

H2N

Figure 4 L-Tryptophan

compound and (thio)urea is known as Biginelli reactionVarious organocatalysts such as tartaric acid oxalic acidcitric acid and lactic acid were found effective in producingBiginelli products [164ndash172]

Because of the ldquoprivilegedrdquo green nature of this fieldit has become an obligation for scientific community andacademic institutions to be mindful and teach this branchof catalysis to students and also keep it as a driving force inthe generation and dissemination of knowledge in pursuitof efficient synthetic methodologies and processes usingorganocatalysts The synthesis of new chiral building blocksor complex molecular structures involving organocatalyticstep(s) is being reported almost every day in scientificliterature As it is not possible here to discuss all the catalystsindividually in detail the author decides to present salientdevelopments in organocatalysis and allied research areas

Synthesis of prochiral cyclohexanones by amine cat-alyzed self-Diels-Alder reactions of 120572120573-unsaturated ketonesin water brought coupled the concept of green chemistry

with catalysis Useful asymmetric heterodomino reactionsfor the highly diastereoselective synthesis of symmetri-cal and nonsymmetrical synthons of benzoannelated cen-tropolyquinanes were reported [173 174]

In recent years trials are being made by using aminoacids especially L-proline to catalyze essential transforma-tions in the fine chemical and pharmaceutical industriesTheinterest in this field has thus increased spectacularly in the lastfew years However organocatalytic methods often requirecatalyst loadings as high as 30mol for the achievement ofhigh conversions in reasonable reaction times [175] Somecritics suggest that low turnover numbers might limit thepotential uses of organocatalysis for industrial applicationsProcess development and scale-up are being tested for severalorganocatalytic reactions confirming organocatalysis as avaluable tool for industrial scale solutions Scientists arereporting novel organocatalytic systems in various reputedinternational research journals and those catalysts exhibitvarious valuable functions derived from a variety of struc-tural ionicelectronic and chemical properties Broad varietyof efficient syntheses will contribute to an increasing numberof organocatalytic large scale reactions in the future Theorganocatalysts shall be used in various fields especially inasymmetric organic synthesis

73 Amine and Chiral Vicinal Diamines Proline and pyrro-lidine derivatives commonly known as Hayashi-Joslashrgensencatalysts in the form of ferrocenyl pyrrolidine are appliedas organocatalyst wherein the ferrocene moiety controls theconformational space and a simple alkyl group effectivelycovers a face of the derived enamine (Figure 5) [180]

Journal of Catalysts 11

R

RNR

REthanol rt

N

O

H

N

R R

+

10mol catalyst

R1

R1

R1R2

R3H2N

middotTfOH

Scheme 6

H NH

O

R

trans H N

O

H

RCis

Reactive conformation

Si

O

H

R

H

Ph

O

Ph

HO

SiCl3 Cl3

Scheme 7

Sulzer-Mosse and Alexakis reported chiral amines cat-alyzing asymmetric conjugate addition to nitroolefins andvinyl sulfones via enamine activation [181]

A bifunctional H-bond directing aminocatalytic systemis found to achieve high stereo- and regiocontrol overdienamine mediated hetero-Diels-Alder reaction [183]

Though amine catalysis is constructing a wide varietyof chiral scaffolds in asymmetric synthesis organocatalysiswith amines for nonasymmetric transformations is alsodeveloping very fast [184 185] The [2+2] cycloaddition ofenals with nitroalkenes is catalyzed by a chiral secondaryamine in the presence of an achiral thiourea for the enantio-and diastereoselective synthesis of highly functionalizedcyclobutanes Mechanistically two consecutiveMichael reac-tions proceed through an unprecedented combination ofdienamineiminium activation mode [186] The reactionengineering of dienamine catalysis for single-step synthesesof highly functionalized molecules such as natural productsor bioactive compounds is reviewed in literature [187]

Chin and coworkers have recently reported some pre-liminary theoretical and experimental studies for convertinga parent diamine into other chiral vicinal diamines Thesediamines can be handy as ligands for chiral catalysts or theycanmake chiral heterocyclic rings and betalactams [188ndash190]

There are some CndashC bonds forming reactions catalyzed bysuch diamine organocatalysts (Scheme 6) [191]

74 Amides Recently the synthesis of multifunctional or-ganocatalysts easily obtained by the condensation of (S)-proline with 2-aminopyridine 26-diaminopyridine or 2-aminoimidazole is reported These chiral prolinamides pro-moted the aldol condensation between cyclohexanone anddifferent aromatic aldehydes (up to 98ee) and also catalyzedDiels-Alder and Michael reactions [192 193]

Rationally designed pyrazole amides function as Michaeldonors in urea catalyzed asymmetric Michael reactions withexcellent chemical and optical yields [194]

A structure-activity relationship with regard to for-mamides as organocatalysts is exploredThis study highlightsthat the cis-conformation of secondary formamides is thereactive conformation in the allylation of aldehydes withallyltrichlorosilane (Scheme 7) [195]

75 Imidazolidinones A certain class of imidazolidinonecompounds (also called MacMillan imidazolidinone organ-ocatalysts) function as catalysts for many asymmetric organictransformations such as asymmetric Diels-Alder reactions

12 Journal of Catalysts

O

N

O

H

O

Up to 97 ee

OHH

N

NO

H20 mol catalyst

CHCl3 minus30∘C

C2H5O OC2H5

R1

R1

R2

R2

+

middotCF3CO2H

Scheme 8 Ouellet et al [202]

R

R

N

One favoured conformer

High enantioselectivity

R = alkyl

Fe

Figure 5

The original such compound was derived from the chi-ral biomolecule phenylalanine [196 197] The first highlyenantioselective organocatalytic Diels-Alder reaction usinga chiral organocatalyst was reported in MacMillanrsquos pio-neering work where the activated iminium ion formedthrough condensation of the imidazolidinone and an 120572120573-unsaturated aldehyde reacted with various dienes to give[4+2] cycloadducts in excellent yields and enantioselectivi-ties Ahrendt et al reportedmany other asymmetric reactionssuch as the 13-dipolar cycloadditions Friedel-Crafts alky-lations 120572-chlorinations 120572-fluorinations and intramolecularMichael reactions usingMacMillanrsquos organocatalysts [96 150198ndash201]

Ouellet et al also reported the combination of imida-zolidinone organocatalyst and Hantzsch ester to facilitatethe first enantioselective organocatalytic hydride reductionof 120572120573-unsaturated aldehydes (Scheme 8) [202 203] Thisimitated naturersquos stereoselective enzymatic transfer hydro-genation with NADH cofactor

Noncovalent interaction is a structure-reactivity andconformation deciding factor which requires immediateattention for understanding organocatalysis [204] Of specialinterest would be the identifying and understanding of othernoncovalent interactions such as charge transfer [205] pndashp stacking immobilization [206] and adsorption or entrap-ment of organocatalysts in nanomaterials [207]

Homogeneous and HeterogenizedMacMillanrsquos OrganocatalystAn asymmetric Diels-Alder reaction was catalyzed with highefficiency and recyclability by a soluble ldquoself-supportedrdquochiral organosilica polymer with embedded imidazolidinonecatalytic moieties [208]

76 Chiral Phosphoric Acids BINOL derived phosphoricacids catalyze nucleophilic addition reactions to imine sub-strates A direct Pictet-Spengler reaction was reported usinga geminally disubstituted tryptamine organocatalyst to formisoquinolines in excellent yield and enantiomeric excess[209] Phosphoric acid catalyzing the reduction of an iminewith a Hantzsch ester in good enantiomeric excess was firstlyreported by Rueping et al Hoffmann et al reported animprovement to this methodology [210 211]

Storer research group reported a one-pot reductive ami-nation of a range of methyl ketones and aryl amines [212]Reductive amination of 2-butanone over silylated phosphoricacid MacMillan TiPSY catalyst was obtained with goodenantiomeric excess

Zhou and List published on the use of chiral Broslashnstedacid (R)-TRIP for highly enantioselective synthesis of phar-maceutically relevant 3-substituted cyclohexylamines from26-diketones wherein the achiral amine substrate acceleratesthe cascade reaction before getting incorporated into the finalproduct (Scheme 9) [213]

Rowland et al reported VAPOL derived phosphoric acidcatalyzed addition of sulfonamides to BOC protected arylimines and protected aminals in excellent enantioselectivities[214]

The (R)-TRIP catalyzed the aza-Diels-Alder reaction ofaldimines with Danishefskyrsquos diene to yield piperidinonederivatives with high enantioselectivity Addition of aceticacid was found to improve both reactivity and enantiose-lectivity [215] Six chemical bonds five stereogenic centersand three cycles were formed in one-pot four-componentUgitype reaction catalyzed by a chiral BINOLderived phosphoricacid [216] BINAP is one of the earliy commercially appliedligands in industrial catalysis [217] Amicroporous recyclableheterogeneous catalyst offering excellent enantioselectivitywas made from a 111015840-binaphthalene-221015840-diol (binol) derivedphosphoric acid chloride and was found as active as thecorresponding homogeneous catalyst [218]

Journal of Catalysts 13

O

O

Ph

OEt HH

Ph

HN

OEt

i-Pr

i-Pr

i-Pri-Pr

i-Pr

i-Pr

O

OP O

OH

EtO2C CO2Et

CyclohexaneMS 5 A 50∘C

NH2

(R)-TRIP (10mol)

82 dr = 24 1 er = 98 21 22

Scheme 9 Zhou and List [213]

NO

N NHH N

HO

S

N

H R

BocO-PrTBS-O

Pr-O

HN

Boc

5mol catalyst+

t-Bu

t-Bu t-Bu

(2) TFA 2min(1) Toluene minus30∘C 48hr

86ndash98 ee

Scheme 10

HO OH

O O

Figure 6

77 Chiral Diols Huang et al reported on use of TADDOLs(Figure 6) as Broslashnsted acid organocatalysts in highly stereos-elective hetero-Diels-Alder reactions [219]

The 120572-amination of carbonyl compounds has also beenaccomplished by using the 1-naphthyl TADDOL derivative asa Broslashnsted acid organocatalyst [220] McDougal and Schausreported asymmetric Morita-Baylis-Hillman reaction that

is the addition of cyclohexenone to different aldehydescatalyzed by octahydro-BINOL derived Broslashnsted acid [221]

78 JacobsenThioureas ProfessorsVachal and Jacobsen iden-tified chiral thioureas (Figure 7) as versatile and effectiveorganocatalysts 1mol of the thiourea was reported to havecatalytic activity in the hydrocyanation (Strecker reaction) ofboth aldimines and ketoimines with very high enantioselec-tivities [222]

Imine hydrophosphonylation particularly effective withelectron-withdrawing ester substituents on the phosphatetook place in the presence of 10mol of the catalyst [223]Mannich reactions of BOC protected imines have also beenreported (Scheme 10) [224] with excellent yields and enan-tioselectivities and show heterocyclic substrate tolerance

A variant of thiourea organocatalyst was found to catalyzethe cyanosilylation of ketones and aldehydes in high yieldsand enantiomeric excesses [225] Thiourea organocatalystwas put to use in the acyl-Pictet-Spengler reaction to formtetrahydro-120573-carbolines [226] The acyl-Mannich reactionproviding a route to enantioenriched heterocycles from

14 Journal of Catalysts

N N N

H H NO H

HO

O

O

O

t-Bu

t-Bu

t-Bu

Figure 7

aromatic starting materials and trichloroethyl chloroformate(TrocCl) is also catalyzed by the thiourea organocatalyst[227] Bifunctional thiourea-base catalyzed double-Michaeladdition of benzofuran-2-ones to dienones is reported forthe synthesis of optically enriched spirocyclic benzofuran-2-ones [228] In another interesting example benzoylthiourea-pyrrolidine catalyst was synthesized and used in the asym-metric Michael addition of ketones to nitroalkenes [229]

Primary amine-thioureas were improvised to catalyzedifficult Michael reactions synthesizing (S)-baclofen (R)-baclofen and (S)-phenibut [230]

79 Cinchona Alkaloids The cinchona alkaloids catalyzemany useful processes with high enantioselectivities Asym-metric phase transfer catalysis (PTC) presents a ldquogreenrdquoalternative to homogeneous synthetic organic chemistrymethodologies Cinchona alkaloids are synthetically mod-ified for their usage in asymmetric PTC O-Alkyl N-arylmethyl derivatives of cinchona alkaloid led highly enantiose-lective alkylation of glycine imines to generate 120572-amino acidderivatives And for the same reaction dimeric cinchonaalkaloid obtained 97ndash99 enantiomeric excess [231 232]Cinchona alkaloids deprotonate substrates with relativelyacidic protons forming a contact ion pair between the result-ing anion and protonated amineThis interaction generates achiral pool around the anion and facilitates enantioselectivereactions with electrophiles The control over the formationof quaternary asymmetric centers is essential to obtain highenantiomeric excesses The 120572-functionalization of ketones(Scheme 11) by the addition of TMSCN to the correspondingcyanohydrin in excellent yield and enantiomeric excess iscatalyzed by the (DHQD)

2AQN catalyst [233]

Increasingly remote stereocenters are being targeted inasymmetric aminocatalysis Organocatalytic allylic amina-tion presents an alternative to the conventional palladiumcatalyzed methodology Amination at the remote 120574-positionusing (DHQ)

2PYR forms highly functionalized amine com-

pounds [234]Bella and Joslashrgensenrsquos reported the first enantioselective

conjugate addition of 120573-diketones to both aromatic andaliphatic alkynones using (DHQ)

2PHAL catalyst [235] Cin-

chona based primary amine catalysis is found to offer high

efficiency and reliability in the asymmetric functionalizationof carbonyl compounds [236 237] Organocatalysts derivedfrom cinchona alkaloids function as Lewis base catalyst inthe cyclizations of allenoates with electron deficient olefinsand imines and emerged as important synthetic tool inthe preparation of biologically active and pharmaceuticallyinteresting cyclic compounds including natural products[238] Recently cinchona thioureas have been reported forthe first time as catalysts in the area of asymmetric oxi-dations [239] Cinchona and cinchonidine derived catalystsperform asymmetric direct aldol reaction of pyruvic aldehydedimethyl acetal with isatin derivatives [240] Likewise thereare various other examples reported where cinchona or itsvariants are used as organocatalysts for syntheses of variousbiologically important molecules [241ndash246]

710 Maruoka Phase Transfer Catalysts The chiral catalystforms a host-guest complex with the substrate and shuttlesbetween the standard organic solvent and a second phaseexample catalytic enantioselective enolate alkylation [72]As we know chiral quaternary ammonium catalysts can beuseful in asymmetric synthesis Kitamura et al reported C2-symmetric ammonium salts catalyzing monoalkylation ofglycine derived Schiff bases with alkyl halides to synthesize120572-alkyl-120572-amino acids under remarkably low catalyst loadings[247ndash249]

Utilizing the solubility of aqueous quaternary ammoniumsalts into organic solvents professor Maruoka developedspirotype chiral ammonium salt with two binaphthyl ringsas a novel chiral phase transfer catalyst Figure 8 depicts theorganocatalyst for direct asymmetric aldol reaction of 120573-hydroxy-120572-amino acid derivative

711 Oxazaborolidines Chiral oxazaborolidines (known asCBS oxazaborolidines after Corey Bakshi and Shibata)catalyze the reduction of prochiral ketones imines andoximes to produce chiral alcohols amines and amino alco-hols respectively in high yields and excellent enantiomericexcesses The chiral Lewis acid generated from o-tolyl-CBS-oxazaborolidine after protonation with trifluoromethanesul-fonimide is very useful in the enantioselective Diels-Alderreaction (Scheme 12) [250ndash256]

Journal of Catalysts 15

O NC OTMSN

OH

N

N

OH

N

OO

2 to 20mol catalyst

TMSCN CHCl3

OC2H5

OC2H5

OC2H5

OC2H5

H3CO

C6H5C6H5

OCH3

Scheme 11 Tian et al [233]

OO

O

OO

II

CH3CH3

CH3

H3C

H3C TIPSOTIPSO

H

H

H

PhPh

NB

minus

+

+

(CF3SO2)2N

20mol catalyst

16hoursDichloromethane minus78∘C

Scheme 12 See [250ndash256]

712 Shi Epoxidation Catalyst Tu et al reported a fructosederived ketone in efficient asymmetric epoxidation of trans-olefins (Scheme 13) [257] Epoxidation catalyst is able toepoxidize trans-alkenes and certain cis-alkenes with good toexcellent yields and selectivities [258 259] Marigo et alrsquosgroup reported an asymmetric organocatalytic epoxidationof 120572 120573-unsaturated aldehydes with environmentally friendlyoxidant hydrogen peroxide [260]

713 N-Heterocyclic Carbene (NHC) as Organocatalysts

7131 Rovis Catalyst The conjugate addition of an aldehydeto an 120572120573-unsaturated compound (Stetter reaction) is apractical methodology for the construction of 14-dicarbonylcompounds bearing quaternary stereocenters Triazoliumsalt in the presence of a base functions as an N-heterocycliccarbene organocatalyst (Figure 9) in highly enantioselectiveintramolecular Stetter reactions [261 262]

7132 Bode Catalyst Bodersquos studies on NHCs (Figure 10)mainly involve catalytic generation of reactive speciessuch as enolates homoenolates and activated carboxylates

N-Mesityl substituent on an imidazolium or triazoliumNHCprecursor generates highly enantioselective annulations fromsimple starting materials under mild reaction conditions[263 264] In an interesting example the catalysts facilitatehighly enantioselective cyclopentene forming annulations ofsimple enals and activated enones [265] Redox esterificationsand amidations of 120572-functionalized aldehydes using achiralcatalyst are also reported [266] Uniting unique activationmodes of N-heterocyclic carbene (NHC) catalysts with theconcept of domino reactions a new fast-growing field cameinto the spotlight in last couple of years or so [267ndash269]

Domino Michaelaldol reaction between 2-mercapto-quinoline-3-carbaldehydes and enals was catalyzed by di-phenylprolinol silyl ether producing 2H-thiopyrano[23-b]-quinolines in excellent yields and enantioselectivities [270]Zhao et al reported studies on ldquocooperative NHC andrutheniun redox catalysisrdquo in the oxidative esterificationof aldehydes [271] Blanc et al reported NHC mediatedorganocatalytic one-pot allylstannation to generate syn-diols[272] With enals as starting aldehydes elegant cascadeprocesses have been developed using oxidative carbene catal-ysis [273ndash276] Over the last few years there are examplesreported in literature where various organocatalysts rally

16 Journal of Catalysts

O

Oxone

OO

O

O

OO

R1 R1

R3

R3

R2 R2H2OCH3CN

Scheme 13

F3C

N+

F3C

Brminus

CF3

CF3

Figure 8 See [176]

N

O

N

N

F

F

F

F

F

+BF4minus

Figure 9

domino reactions and attract their application in organicprocesses in industries [174 175 180 181 183]

Apart from the aforementioned organocatalysts thereare other organic systems which upon appropriate acti-vation function as catalysts in useful asymmetric synthe-ses [155ndash157] 12-Dicarbonyl compounds because of theiradjacent multiple reactive centers upon activation act asefficient pronucleophiles in asymmetric organocatalyzed

N

O

NN+

Clminus

Figure 10

sequential or domino transformations including CndashC or CndashN bond formation [277] Cyclopropenone catalyzed con-version of aldoximes and primary amides into nitriles ina one-pot mild reaction widens the scope of the utiliza-tion of cyclopropenones in organic synthesis [278] Thefirst asymmetric organocatalytic synthesis by phosphinecatalyzed [3+2] cycloaddition of allenoates onto fullereneis reported to yield enantiomerically pure carbocyclicfullerene derivatives under mild conditions [279] A new[3+2] cycloadditioncycloreversion strategy for organocat-alytic and thermally allowed carbonyl-olefin metathesis isreported [280] Recently a strong evidence for halogenbond based organocatalysis is reported for the reactionof 1-chloroisochroman with ketene silyl acetals [281] Acidcatalyzed asymmetric acetalizations of aldehydes are alsodescribed [282] beta-Isocupreidine catalyzed the enantios-elective Morita-Baylis-Hillman reaction of maleimides withisatin derivatives to form 3-substituted 3-hydroxyoxindolederivatives [283 284]

Recent advances in asymmetric catalysis resulted in uti-lizing the less discussed electrophilic properties of iminiumtype intermediates in complex annulations of indoles [285286] and also pyridines [287 288] Shibatomi and Narayamadiscussed the catalytic enantioselective 120572-chlorination of car-bonyl compounds and stereospecific substitution reactions ofthe resulting optically active alkyl chlorides [289]

Though there is no relation between the developmentof two different fields of organocatalysis and gold catalysis

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

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[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

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[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

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[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

2 Journal of Catalysts

(1) P

reve

nt w

aste

(2) M

axim

ize a

tom

econ

omy

(3) L

ess h

azar

dous

chem

ical

synt

hesis

(4) Safer chemicals and products

(5) Safety solvents and reaction conditions

(6) Increase energy efficiency

(7) U

se re

new

able

feed

stock

s

(8) A

void

chem

ical

der

ivat

ives

(pro

tect

ing

grou

ps)

(9) U

se ca

taly

sts

(10) Design chemicalsand products to degrade after use

(11) Analyze in real timeto prevent pollution

(12) Minimize potentialfor accidents

Figure 1 Inspired by the 12 principles of green chemistry from [3]

2 Catalysis A MultidisciplinaryArea of Chemistry

Catalyst is one of the few conceptual words that havecarried over broadly outside scientific language Catalysis isa significant multidisciplinary area of chemistry The termldquocatalysisrdquo was first introduced in 1836 by Berzelius whotried to explain special powers of some chemical substancescapable of influencing various decomposition and chemicaltransformations

According to Ostwald [6] ldquoa catalyst accelerates a chemi-cal reaction without affecting the position of the equilibriumrdquoA catalyst works by interacting with reactants generatingintermediates that react to give products It affects the rate ofapproach to equilibrium of a reaction but not the position ofthe equilibrium (Figure 2) Most of the times it also providessubtle control of chemical conversions increasing the rate ofa desired reaction pathway but not the rates of undesired sidereactions (ie the selectivity of a chemical process)

Catalysts are usually classified according to structurecomposition area of application or state of aggregation

Reaction coordinate

Transition state

Catalysis

Ener

gy

C + DA + B

Ea

Figure 2 Schematic illustration of the effect of a catalyst on thetransformation of A + B into C + D

Journal of Catalysts 3

According to the state of aggregation in which the catalystsact there are two main groups homogeneous catalysts andheterogeneous catalysts Homogeneous catalysts are well-defined chemical compounds or coordination complexeswhich together with the reactants are molecularly dispersedin the reaction medium and carry out processes in a uniformgas or liquid phase Heterogeneous catalysis takes placebetween different phases Generally the catalyst is in solidstate and the reactants are gases or liquids The immobilizedcatalysts obtained by attaching homogeneous catalysts tosolid are in between In supported catalysts the catalyticallyactive substance is applied to a support material that hasa large surface area and is usually porous Arguments forand against shall always be made while discussing the meritsand limitations of individual groups of catalysts for theirrespective applications in industries

3 Application of Catalysis

Catalysis has played a pivotal role in the success of thechemistry industry in the twentieth century More than 90of chemical manufacturing processes in the world utilizecatalysts [7 8] Historically the first industrially appliedcatalytic process was for the hydrogenation of oils and fatsto produce margarine using finely divided nickel as catalystThus heterogeneous catalysis was applied first industriallyThe issue of metal leaching and the avoidance of tracecatalyst residues are very important from environmentalhealth point of view All the basic raw materials or buildingblocks for chemicals are manufactured by very important setof heterogeneous catalytic reactions (Table 1) [8] Althoughcatalysts are not consumed by the reaction itself they may beinhibited deactivated or destroyed by secondary processesThe solid-state catalyticmaterials are themost important typeof catalysts

Implementation of ldquocleanrdquo and ldquogreenrdquo chemical technol-ogy in industries may help address the problem of envi-ronmental degradation besides producing useful chemicals[9ndash12] Some catalysts also present important technology inthe prevention of emissions for example catalytic converterfor automobiles Keeping in mind the fragile ecosystem andthe importance of preserving the environment the hetero-geneous catalysts are tested in the pollution abatement [1314] and to remove aqueous organic wastes volatile organiccompound and vehicular primary emissions such as COunburned hydrocarbon NOx and soot

Heterogeneous catalysis which takes place between dif-ferent phases has now grown into an important branch ofscience [8ndash12 15] Exciting new opportunities are emergingin this field based on nanotechnology approaches Henceresearch efforts are being directed to develop chemistry ofnanomaterials and their applications in catalysis for devel-oping cost-effective selective energy sufficient ecofriendlyand environmentally benign synthetic processes for indus-tries Though this involves a great scientific economic andtechnological challenge it is essential to a sustainable andhealthy way of life

The petroleum and fine chemical and pharmaceuticalindustries mostly rely on catalysts to produce everything

from natural gasfuels to various commodities [15 16] Thereare a variety of new challenges in creating alternative fuelsreducing harmful by-products in manufacturing cleaningup the environment and preventing future pollution deal-ing with the causes of global warming and creating safechemicals and pharmaceuticals Thus catalysts are needed tomeet these challenges of health safety and environmentalenergy-related and economic issues but their complexityand diversity demand an insight on the way catalysts arestudied designed and used This could come into realityonly through the application of an interdisciplinary approachinvolving new methods for synthesizing and characteriz-ing molecular and material systems Research in heteroge-neous catalysis demands the cooperation of scientists fromanalytical chemistry solid-state chemistry (nano)materialschemistry physical chemistry surface science computationaland theoretical chemistry reaction kinetics and mecha-nisms reaction engineering and so forth Opportunities tounderstand and predict how catalysts work at the atomicscale are now appearing made possible by breakthroughsin the last decade in computation measurement techniquescharacterization spectroscopy and imaging and especiallyby new developments in surface-reactivity studies modelcatalyst design and evaluation [16 17] Surface science andspectroscopy has its prominent role in analysing surfacereaction chemistry on the catalyst [18 19]

Fermentation of sugar to ethanol and the conversionof ethanol to acetic acid catalyzed by enzymes were anexample of catalysis in antiquity Off late enzymatic catalysisis considered as a separate branch of (biological) catalysis It isthe most recent branch widely included in many commercialapplications [20 21] Enzymes are also highly active undermild conditions such as temperature pressure and pHwhichmake them easier to work with on a small scale but are alsomore appealing on an industrial scale on a cost and efficiencybasis Another benefit is that reactions are preferentiallycarried out in aqueous media therefore providing a ldquogreenerrdquoroute Not to forget the development of water based organictransformations is also an area of rapidly growing importancein chemistry [22 23]

The homogeneous catalysis prior to the recognition ofthe effects of heterogeneous catalysts started with the actionof nitrous oxides in the lead chamber process Althoughthe fundamental processes for refining petroleum and itsconversion to basic building blocks are based on heteroge-neous catalysts many important value-added products aremanufactured by homogeneous catalytic processes (Table 2)[12] Homogeneous catalysts have been well researchedsince their catalytic centers can be relatively easily definedand understood but difficulties in separation and catalystregeneration prevent their wider use [12 24ndash28] The mostwidely used homogeneous catalysts are simple acids orbases which catalyze well-known reactions such as esterand amide hydrolysis or esterification The market share ofhomogeneous catalysts is estimated to be only ca 10ndash15Many of the benefits of homogeneous catalysts especiallyhigh selectivity arise from tailored made catalysts involvingtransition metals (or lanthanides) and appropriate ligandsSuch catalysts are inexpensive enough that they can be

4 Journal of Catalysts

Table 1 List of some of the industrially applied reactions and catalysts

Reaction Catalyst Inventor (Year)Sulphuric acid (leadmdashchamber process) NO

119909Clement Desormes (1806)

Chlorine production by HCl oxidation CuSO4 Deacon (1867)Nitric acid by NH3 oxidation Pt Rh nets Ostwald (1906)Fat hardening Ni Normann (1907)

Ammonia synthesis (H2 + N2) Fe Mittach Haber Bosch (1908)Production 1913 BASF

Hydrogenation of coal to hydrocarbons Fe Mo Sn Bergius (1913) Pier (1927)Methanol synthesis from CoH2 ZnoCr2O3 Mittach (1923)Hydrocarbons from COH2 (motor fuels) Fe Co Ni Fischer Tropsch (1925)Alkylation of olefins to gasoline AlCl3 Pines (1932)Cracking of hydrocarbons Al2O3SiO2 Houdry (1937)Cracking in a fluidized bed Aluminosilicates Lewis Gilliland (1939)Ethylene polymerization at low pressure Ti compounds Ziegler Natta (1954)Hydrogenation isomerization hydroformylation Rh- Ru complexes Wilkinson (1964)

Methanol carbonylation to acetic acidCoiodide BASF (1960)Rhiodide Monsanto Co (1966)Iridium BP Chemicals Ltd (2000)

Asymmetric hydrogenation Rhchiral phosphine Knowles (1974)Three-way catalyst Pt Rhmonolith General Motors (1974)Methanol conversion to hydrocarbons Zeolites Mobil Chemical Co (1975)Alpha-olefins from ethylene Nichelate phosphine Shell company (1977)Sharpless (epi) oxidation TIROOHTartarate May Baker Upjohn ARCO (1981)Selective oxidations with H2O2 TS-1 (titanium silicate) Enichem (1983)Hydroformylation Rhphosphine Rhone-Poulene-Ruhrchemie (1984)Polymerization of olefins ZirconoceneMAO Sinn Kaminsky (1985)Selective catalytic reduction (SCR) V W Ti oxidesmonolith 1986

Table 2 Differences between homogeneous catalysts and heteroge-neous catalysts

Homogeneous catalysts Heterogeneous catalystsSame phase as reaction medium Solid phaseDifficult separation Easily separableNo recyclability Recyclability and regenerationOften high rates of reaction Low rates of reactionNo diffusion control Diffusion controlRobust to poisoning Poisoning deactivationHigh selectivity Low selectivityShort life Long catalytic lifeMild conditions Energy-consuming processWell understood mechanism Poor mechanistic understanding

neutralized easily separated from organic materials anddisposed of This contributes to the huge quantity of aqueoussalt waste generated by industry Organometallic catalysts arecurrently widely used in industry but the search for improvedefficiencies enantioselectivities or recycling is still a matterof intense researches [29ndash33] It is true that homogeneouslycatalyzed processes such as hydroformylation carbonylationoxidation hydrogenation metathesis and hydrocyanationcontribute with millions of tons to the bulk chemicals but

on the other hand the progress of homogeneous catalysisis also going on with fine chemicals [25 33] In spirit ofthat the beginning of this century saw the renaissance oforganocatalysis presenting an environmental advantage overmetal based catalysts for stereoselective or asymmetric syn-thetic methodologiesThe absence of metal in organocatalystbrings an undeniable advantage considering the principles ofldquogreen chemistryrdquo and the economic point of view (Tables 3and 4)

Understanding catalytic systems involve study of struc-ture state and composition of catalysts and the phase inwhich they perform And for this one needs to understandchemistry of molecules and materials useful as catalysts andor catalyst carriers

4 Materials for Catalysis

The diversity of research field connected to the chemistry ofmaterials is significant for their applications in many areasincluding adsorption catalysis electrochemistry and surfacescience Nanoparticles [34] metal oxide and mixed metaloxides [35ndash38] prepared by simple methods are useful cata-lysts Research involving metal-organic frameworks [39 40]mesoporous silica [41ndash43] microporous or open-frameworkinorganic [44ndash46] andor mesopore modified [47] materials

Journal of Catalysts 5

Table 3 Comparison among organometallic catalysts enzyme catalysts and organocatalysts

Organometallic catalyst Enzyme catalyst Organocatalyst

Wide substrate scope high catalyticactivity involving tedious processpotential heavy metal pollution

Limited substrate scope highselectivity and catalytic activity

usually single enantiomer

Robust inexpensive readily available nontoxic inert towardmoisture and oxygen method especially attractive for the

preparation of compound that do not tolerate metal contamination(pharmaceutical products)

Table 4 Advantages and disadvantages of organocatalysts

Advantages DisadvantagesEasy preparation or availability High catalyst loadingEasy handling inert towards moisture(water) and air (oxygen) Relatively premature field

Easy scale-upNo metal contaminationEasy screeningUseful in complex (steric) reactions

has steadily increased following the widespread utility ofaluminosilicate zeolites [48ndash51] titanosilicates [52 53] andaluminium phosphates [54 55]

In industries research endeavours are mainly devotedtowards the study and development of zeolites or zeoliticmaterials with several attractive features such as cat-alytic active site(s) large surface area zeolitic pore wallsand pore size control The synthesis and characteriza-tion of the crystalline aluminosilicate materials with tun-able meso-microporosity and their strong acidity havepotentially important technological implications for shape-selective catalytic reactions ion exchange and adsorption oforganic compounds [56ndash58]Thepore diameters can be finelychosen tuned and utilized for exhibiting shape-selectivecatalysis depending on the molecular shapesize of organicreactant and product The widespread interest has beendeveloped in the zeolitic science towards the developmentand discovery of zeolites with desired characteristics sinceconventional zeolites lack fine tuning of their properties toacidbase and redox or bifunctional or multifunctional prop-erties Organic functionalization adds new catalytic functionsto zeolites [59]

Zeolites are microporous crystalline aluminosilicateswith unique properties used for many processes Zeolitespossess acid sites that are associated with the tetrahedralaluminium atoms in their framework and therefore theamount of acidity depends on the aluminium content ofthe zeolite Zeolite acid catalysts have wide application inindustrial processesThe introduction of Y-zeolites to replaceamorphous silica-alumina in fluidized catalytic cracking(FCC) and in hydrocracking processes in the early 1960rsquos wasa breakthrough application in acid catalysis With the everincreasing research efforts in this area leading to discoveriesof new structures and modification schemes by academicand industrial laboratories the potential of solid acids hasevolved tremendously However with the exception of theZSM-5 Mordenite and to some extent Beta zeolite very few

of these structures have been applied in industrial processesto any significant extent Yet one can account for relativelyfew applications to the huge number of new materialsintroduced Notable examples are the reported uses of SAPOsin lube dewaxing and in natural gas to olefin technologiesand MCM-22 in aromatics alkylation The zeolite structureswith large-porebimodal porosity and tunable acidity canbe a remarkable benefit for catalytic processes in industriesWithin industrial catalysis there are constant innovation andchanging approaches to provision of selective economicallyviable and environmentally benign processes

Recently enormous growth in the chemical diversity ofinorganic materials with transition-metal incorporation innew compositional domains has also been explored dueto their potential application in adsorption and catalysisInorganic polymers transition metal phosphates and metal-organic frameworks [39 40] with novel catalytic electronicmagnetic and unique structural properties are particularlypromising candidates [60ndash64] The mesoporous structurewith strong acidity can be a remarkable benefit for catalyticreactions involving large organic molecules in which diffu-sion constraints andor adsorption of reactantmolecules ontothe strong acid sites are the main concern A lot has beenreported about the pathways to developmesostructured silica[65] In terms of surface functionalization the performanceof mesoporous silica has been polished by several methodssuch as metal incorporation [66] metal deposition [67]grafting by organic functional groups [68] and immobiliz-ing metal complex [69] New approaches to synthesis andcharacterization of bimodal that is micro-mesoporous andor meso-macroporous materials might assist us in under-standing the phenomena of diffusion confinement effectsselectivity and so forth [47]

5 Organocatalysis A NovelSynthetic Philosophy

The term ldquoorganocatalystrdquo is a concatenation of the wordsldquoorganicrdquo and ldquocatalystrdquo The definition corresponds to a lowmolecular weight organicmolecule which in substoichiomet-ric amounts catalyzes a chemical reactionThe organocatalystcould be achiral or chiral and could be composed of CH N S and P Organocatalysis has several advantages notonly because of its synthetic range but also for the economicreasons The absence of metal in organocatalyst brings anundeniable advantage considering both the principles ofldquogreen chemistryrdquo and the economic point of view (Figure 3)

Nowadays organocatalysis is one of the hot researchtopics in advanced organic chemistry It is a novel syn-thetic philosophy and mostly an alternative to the prevalent

6 Journal of Catalysts

N

H

L-ProlineN

N

DMAP

OH

Nobin

N

NO

H

MacMillanrsquos catalyst

O

N

HO N

Quinine

CO2H

NH2

∙ ∙

Figure 3 Few famous examples of organocatalysts L-proline DMAP quinine and MacMillanrsquos catalyst

transition metal catalysis Organocatalysts are often basedon nontoxic organic compounds originating from biologicalmaterials Organocatalysts can be Lewis bases Lewis acidsBroslashnsted bases and Broslashnsted acids Most of the organocatal-ysis reported so far are explained by Lewis base mechanismThe Lewis base mechanism can be simplified as follows

Step I Lewis base for example cinchona alkaloidinitiates catalysis via a nucleophilic addition to ordeprotonation of the substrateStep II the chiral intermediate undergoes reactionStep III separation of product(s) from the catalystoccursStep IV regeneration of the catalyst and its availabilityfor a new catalytic cycle occurs

There are many organocatalytic reactions that need a secondmechanism to explain the catalytic cycle involved This iscalled bifunctional organocatalysis in which the organocata-lyst possesses not only a Lewis base (nitrogen or phosphorusatom) but also a Broslashnsted acidic site There is a lot to be donein redox catalysis and in exploitation of the synergetic effect ofdifferent catalytic active sites within one organic compoundor material

Some advantages of organocatalysts include the following

(i) Reactions performed by organocatalysts have poten-tial application in large scale production in industries

(ii) Scope organic reactions occur which are not inpractice and not possible by other forms of catalystsfor example asymmetric synthetic processes

(iii) PriceAvailability Low cost alkaloids natural aminoacids L-proline tartaric acid and so forth are easilyavailable and are economically attractive

(iv) Recycling issues immobilization of the catalyst is thesimplest way to recover it

(v) Some of the examples include bioderived andbiodegradable organocatalysts

(vi) Organocatalysts work at mild reaction conditions(vii) Sometimes the final products of reactions contain

high levels of metal contamination derived from cat-alyst degradation phenomena which pose a seriousdrawback if the metal is toxic for pharmaceutical andfood industries Absence of transition-metal bringsorganocatalysis at the heart of greening chemistry

Organocatalysis can be categorized into our different typesas follows

Type-I activation of the reaction based on the nucle-ophilicelectrophilic properties of the catalyst is done(Scheme 1)

Type-II organic molecules form reactive intermedi-ates The chiral catalyst is consumed in the reactionand requires regeneration in parallel catalytic cycle asit is reported in Scheme 2

Type-III phase transfer reactions occur The chiralcatalyst forms a host-guest complexwith the substrateand shuttles between the standard organic solvent anda second phase

Journal of Catalysts 7

O

O

O

O

OOH

100

N

H

3mol L-proline

DMF 20∘C 20h

CO2H

Scheme 1 Hajos and Parrish [70]

O

O

OOO

O

O

30mol catalyst

30 H2O2 (3 equivalent)

CH3CNndashK2CO3

R1R3

R2

R1R3

R2

Scheme 2 Shu and Shi [71]

Catalytic enantioselective enolate alkylation(Scheme 3) occurs

Type-IV molecular-cavity-accelerated asymmetrictransformations occur in which the catalyst mayselect from competing substrates depending on sizeand structure criteria (Scheme 4)

6 Discovery and the History ofOrganocatalysis

Liebigrsquos synthesis of oxamide from dicyan and water is thefirst organocatalytic reaction reported [74] Acetaldehydewasfurther identified to behave as the then-named ldquofermentrdquonow called as enzyme Dakin in 1909 demonstrated that ina Knoevenagel type condensation between aldehydes andcarboxylic acids or esters with active methylene groups theamine catalysts could be mediated by amino acids [75]Langenbeck is remembered for developing enamine typereactions and the application of simple amino acids andsmall oligopeptides as catalysts [76ndash78] Natural products inparticular strychnine brucine and cinchona alkaloids andamino acids (including short oligopeptides) were amongthe first organic catalysts tested [79 80] Though the fieldof small-molecule catalysts seems very simple there are

evidences that prove their pivotal role in synthesis of buildingblocks for life L-Alanine andL-isovaline capable of catalyzingcertain CndashC bond formation reactions had been found onmeteorites [81]

An asymmetric transformation with an organic moleculewas published in 1912 by Bredig and Fiske [82] Pracejusapplied cinchona alkaloids in the asymmetric conversionof ketenes to (S)-methyl hydratropate [83 84] An initialresearch byYamadaampOtaniwas important too [85]The sev-enties brought anothermilestone Hajos and Parrish reporteda L-proline catalyzed Robinson annulation in excellent enan-tioselectivities [70 86 87] Eder et al reported organocat-alytic aldol reactions in good enantioselectivities [88] Tosummarize in 1970s Hajos and Parrish and independentlyEder Sauer and Wiechert published a series of papers andpatents involving such organocatalytic transformations Theasymmetric synthesis of enediones useful building blocksin natural product total syntheses was achieved (S)-Prolineinduced the formation of (S)-enediones

Two mechanisms [89] were proposed (1) involving theformation of a carbinolamine intermediate followed by thedisplacement of the proline moiety by nucleophilic attackof the enol from the side chain ketone (2) involving anenaminium intermediate acting as a nucleophile in the CndashCbond formation with concomitant NHsdot sdot sdotO hydrogen trans-fer Wynberg firstly published various 12 and 14 additionscatalyzed by cinchona bifunctional organocatalysis [90ndash92]

8 Journal of Catalysts

N

O

Ph

Ph

Ph

Ph

N

O

OO

O

81 96 eeO

O

O

O

H N

Chiral quaternary ammonium catalyst10mol catalyst

CH2Cl2BrH2C

Ot-Bu

Ot-Buminus78

∘C 24h

+

Brminus

CsOHmiddotH2O

Scheme 3 Corey et al [72]

O

BOCHN BOCHN

OO OH

Nu

OH

(2) Nu

(1) Polymer

HO

N

HN

HO

O

O

OH

NO2

NO2

+

Scheme 4 Sellergren et al [73]

All these research endeavours were not carefully looked intotill List et al reported in 2000 proline catalyzed aldol reactionin good enantiomeric excesses [93 94]

Asymmetric catalysis constitutes one of the most impor-tant subjects in synthetic organic chemistry Asymmetricsynthesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the application of such methodologies inchemical industry is rather limited due to the high cost ofchiral ligands and noble metals used in such transformationsMoreover the pharmaceutical entities and food industryproducts do not tolerate a contamination of even traces ofany such metals for that matter Synthesis of chiral drugshas a major financial impact in pharmaceutical industrieson a global scale Different enantiomers or diastereomers ofa molecule often have different biological activity Most ofthe drugs might be soon sold as single enantiomers in thecoming years There is a huge demand for organocatalystsleading to 100 yield 100 ee of the desired product Theneed from chemical industry especially pharmaceutical forreliable asymmetric transformations of molecular skeletonsis higher than ever Therefore asymmetric organocatalysisis in a process of attaining maturity into a very powerful

practical and broadly applicable methodological approach inthe catalytic asymmetric synthesis

7 Some Examples and Developments inCatalyst Structural Variants

Following are the famous examples of organocatalysts

71 Proline and Derivatives The proline catalyzed Robinsonannulation was one of the earliest examples of an enantios-elective reaction using an organic catalyst [85] This aminoacid contains both a nucleophilic secondary amino groupand a carboxylic acid moiety functioning as a Broslashnstedacid The availability of proline in both enantiomeric formsbrings advantages over enzymatic methods Arguably thefirst example of proline catalyzed asymmetric aldol reactionis reported by Hajos and Parrish [70 86 87] The Wieland-Miescher ketone is a useful synthetic building block forwhich a classical asymmetric procedure using (S)-prolinewas published forty years ago [88] It is quite significant thatthe first efficient organocatalyzed asymmetric reactions weredescribed by Hajos amp Parrish [86 87] and by Eder et al [88]

Journal of Catalysts 9

both teams from pharmaceutical companies (Hoffmann-la-Roche and Schering) The asymmetric synthesis of theWieland-Miescher ketone is also based on proline andanother early application was one of the transformations inthe total synthesis of erythromycin by Woodward et al [95]Proline is recognized as a versatile organocatalyst of thesetimes (Scheme 5)

In fact the renewal of proline catalyzed transformationsin early 2000 by D W C MacMillan Carlos F Barbas IIIand Benjamin List saw the renaissance of the concept and itwas the starting point of the word ldquoorganocatalysisrdquo ProfessorAhrendt group reported the first enantioselective organocat-alytic Diels-Alder reaction [96] Proline was identified asan effective organocatalyst for asymmetric aldol reaction[97] The catalytic asymmetric 120572-alkylation of aldehydeswas reported by Vignola and List [98] This transformationhad been accomplished with the help of covalently attachedauxiliaries 120572-Methyl L-proline exhibits higher enantioselec-tivities and improved reaction rates when compared to L-proline In recent years proline especially L-proline hasbeen used to catalyze essential transformations used in thefine chemical and pharmaceutical industries such as thedirect asymmetric aldol reactions [99ndash107] Diels-Alder reac-tions Michael reactions [108ndash115] Mannich reaction [116ndash122] Multicomponent reactions [123 124] and 120572-amination[125] 120572-aminoxylation [126ndash128] 120572-oxyaldehyde dimer-ization [100] 120572-functionalization of carbonyl compounds[129] and 120572-alkylation of aldehydes [130] Organocat-alytic cyclopropanation reactions were typically performedusing catalyst-bound ylides However Kunz and MacMil-lan demonstrated that activation of olefin substrates usingcatalytic (S)-(minus)-indoline-2-carboxylic acid is a viable routefor the formation of highly enantioenriched cyclopropanes[131]

Prof K A Joslashrgensen has made an importantbreakthrough in asymmetric synthesis by developing (R)-and (S)-120572120572-bis[35-bis(trifluoromethyl)phenyl]-2-pyrroli-dinemethanol trimethylsilyl ether as excellent chiral organ-ocatalysts in the direct organocatalytic 120572-functionaliza-tion of aldehydes Diarylprolinol silyl ether reagents werefound to catalyze CndashC CndashN CndashO CndashS and CndashHal bondforming reactions [132ndash138] Cascade or domino reactionsswiftly construct complex biologically important compoundsand minimize waste and also the laboratory operations [139]Endersrsquo group developed proline derived organocatalyst fora chemo- diastereo- and enantioselective three-componentdomino reaction to yield tetrasubstituted cyclohexenecarbaldehydes [140] The four stereogenic centers aregenerated in three consecutive CndashC bond formations thatis MichaelMichaelaldol condensation with high diastereo-and complete enantiocontrolThe synthesis of polyfunctionalcyclohexene building blocks involving proline catalytic stepsis reported in this domino reaction

Though this segment of our review is dedicated to prolineas an important class of organocatalysts it would also be agood place to acknowledge the research contributions fromprofessor Ahrendt et al to the field of organocatalysis [96 99100 103 127 131 141ndash150]

Heterogenized Proline An explosion of research articles inthe area of homogeneous organocatalysis occurredwithin thelast decade or so In addition to the initial proline catalyzedreactions the word ldquoorganocatalysisrdquo covers nowadays manyotherwell-knownorganocatalysts and organic reactions Pro-line immobilized onto some sort of inorganic support pavesthe way towards heterogenization of other organocatalysts[151ndash153] A simple and efficient synthesis of polystyrene-supported proline and prolinamide is reported Polystyrene-supported proline catalyzes the asymmetric aldol reactionbetween cyclohexanone and substituted benzaldehydes inwater High yields diastereoselectivities and ee values havebeen observedThe versatility of this resinwas also confirmedby selenenylation of aldehydes Both proline and prolinamideresins gave high yields Recycling studies showed that theproline resin performs as better heterogeneous organocat-alyst as compared to the prolinamide resin [153] An aldolreaction catalyzed by proline functionalized silica gel wasinvestigated in continuous flow microreactors by reaction-progress kinetic analysis and nonlinear chromatography[154]

Though the research community advocates asymmetricsynthesis for industrial application organocatalysts havebeen seldom applied in industry due to insufficient efficiencyand the difficulties in catalyst separation and recycling[155ndash161] The concept of heterogenizing organocatalyst onsupports combines the advantages of both homogeneousorganocatalysis and heterogeneous recycling Though thismight seem simple and present opportunities in indus-trial chemical processes the research in heterogeneousorganocatalysis demands a multidisciplinary approach byidentifying catalytic activity upon bonding organocatalystcovalently to the support understanding noncovalent inter-action as structure-reactivity and conformation decidingfactor taking into consideration the characteristic propertiesof the supports confinement effects if any and so forthSome recent examples will be described on the applicationsof supported proline as organocatalysts for their preindus-trialization study The latter half of this review in generalirons out the detailed discussion on key trendswith examplesscope challenges and ldquogreenrdquo applications of heterogeneousorganocatalysts

72 Other Amino Acids Barbas and coworkers found theproteinogenic amino acid tryptophan (Figure 4) to be anexcellent organocatalyst for the Mannich reaction of hydrox-yacetone with a variety of imines performed in DMF leadingthe desired anti-amino alcohols in excellent diastereoselec-tivities (up to gt19 1) and enantioselectivities (90ndash98 ee)Similarly t-butyl protected threonine catalyzed the aldolreaction of hydroxyacetone and various aldehydes in NMP togive the corresponding syn-aldol adducts in high yields andgood to excellent enantio- and diastereoselectivities [162]Zhao et al reported [163] the development of an aminoacid based small molecule capable of promoting asymmetricmonosilylation of meso-12-diols Furthermore the catalystcan be recycled with equal efficiency Three-componentreaction involving condensation of aldehyde 13-carbonyl

10 Journal of Catalysts

NH

OH

OH

O

O NHPh

O PhH

H

ON

NH

H

O OH

CO2BnCO2Bn

NO2

R1 R2

Scheme 5

NH

OH

O

H2N

Figure 4 L-Tryptophan

compound and (thio)urea is known as Biginelli reactionVarious organocatalysts such as tartaric acid oxalic acidcitric acid and lactic acid were found effective in producingBiginelli products [164ndash172]

Because of the ldquoprivilegedrdquo green nature of this fieldit has become an obligation for scientific community andacademic institutions to be mindful and teach this branchof catalysis to students and also keep it as a driving force inthe generation and dissemination of knowledge in pursuitof efficient synthetic methodologies and processes usingorganocatalysts The synthesis of new chiral building blocksor complex molecular structures involving organocatalyticstep(s) is being reported almost every day in scientificliterature As it is not possible here to discuss all the catalystsindividually in detail the author decides to present salientdevelopments in organocatalysis and allied research areas

Synthesis of prochiral cyclohexanones by amine cat-alyzed self-Diels-Alder reactions of 120572120573-unsaturated ketonesin water brought coupled the concept of green chemistry

with catalysis Useful asymmetric heterodomino reactionsfor the highly diastereoselective synthesis of symmetri-cal and nonsymmetrical synthons of benzoannelated cen-tropolyquinanes were reported [173 174]

In recent years trials are being made by using aminoacids especially L-proline to catalyze essential transforma-tions in the fine chemical and pharmaceutical industriesTheinterest in this field has thus increased spectacularly in the lastfew years However organocatalytic methods often requirecatalyst loadings as high as 30mol for the achievement ofhigh conversions in reasonable reaction times [175] Somecritics suggest that low turnover numbers might limit thepotential uses of organocatalysis for industrial applicationsProcess development and scale-up are being tested for severalorganocatalytic reactions confirming organocatalysis as avaluable tool for industrial scale solutions Scientists arereporting novel organocatalytic systems in various reputedinternational research journals and those catalysts exhibitvarious valuable functions derived from a variety of struc-tural ionicelectronic and chemical properties Broad varietyof efficient syntheses will contribute to an increasing numberof organocatalytic large scale reactions in the future Theorganocatalysts shall be used in various fields especially inasymmetric organic synthesis

73 Amine and Chiral Vicinal Diamines Proline and pyrro-lidine derivatives commonly known as Hayashi-Joslashrgensencatalysts in the form of ferrocenyl pyrrolidine are appliedas organocatalyst wherein the ferrocene moiety controls theconformational space and a simple alkyl group effectivelycovers a face of the derived enamine (Figure 5) [180]

Journal of Catalysts 11

R

RNR

REthanol rt

N

O

H

N

R R

+

10mol catalyst

R1

R1

R1R2

R3H2N

middotTfOH

Scheme 6

H NH

O

R

trans H N

O

H

RCis

Reactive conformation

Si

O

H

R

H

Ph

O

Ph

HO

SiCl3 Cl3

Scheme 7

Sulzer-Mosse and Alexakis reported chiral amines cat-alyzing asymmetric conjugate addition to nitroolefins andvinyl sulfones via enamine activation [181]

A bifunctional H-bond directing aminocatalytic systemis found to achieve high stereo- and regiocontrol overdienamine mediated hetero-Diels-Alder reaction [183]

Though amine catalysis is constructing a wide varietyof chiral scaffolds in asymmetric synthesis organocatalysiswith amines for nonasymmetric transformations is alsodeveloping very fast [184 185] The [2+2] cycloaddition ofenals with nitroalkenes is catalyzed by a chiral secondaryamine in the presence of an achiral thiourea for the enantio-and diastereoselective synthesis of highly functionalizedcyclobutanes Mechanistically two consecutiveMichael reac-tions proceed through an unprecedented combination ofdienamineiminium activation mode [186] The reactionengineering of dienamine catalysis for single-step synthesesof highly functionalized molecules such as natural productsor bioactive compounds is reviewed in literature [187]

Chin and coworkers have recently reported some pre-liminary theoretical and experimental studies for convertinga parent diamine into other chiral vicinal diamines Thesediamines can be handy as ligands for chiral catalysts or theycanmake chiral heterocyclic rings and betalactams [188ndash190]

There are some CndashC bonds forming reactions catalyzed bysuch diamine organocatalysts (Scheme 6) [191]

74 Amides Recently the synthesis of multifunctional or-ganocatalysts easily obtained by the condensation of (S)-proline with 2-aminopyridine 26-diaminopyridine or 2-aminoimidazole is reported These chiral prolinamides pro-moted the aldol condensation between cyclohexanone anddifferent aromatic aldehydes (up to 98ee) and also catalyzedDiels-Alder and Michael reactions [192 193]

Rationally designed pyrazole amides function as Michaeldonors in urea catalyzed asymmetric Michael reactions withexcellent chemical and optical yields [194]

A structure-activity relationship with regard to for-mamides as organocatalysts is exploredThis study highlightsthat the cis-conformation of secondary formamides is thereactive conformation in the allylation of aldehydes withallyltrichlorosilane (Scheme 7) [195]

75 Imidazolidinones A certain class of imidazolidinonecompounds (also called MacMillan imidazolidinone organ-ocatalysts) function as catalysts for many asymmetric organictransformations such as asymmetric Diels-Alder reactions

12 Journal of Catalysts

O

N

O

H

O

Up to 97 ee

OHH

N

NO

H20 mol catalyst

CHCl3 minus30∘C

C2H5O OC2H5

R1

R1

R2

R2

+

middotCF3CO2H

Scheme 8 Ouellet et al [202]

R

R

N

One favoured conformer

High enantioselectivity

R = alkyl

Fe

Figure 5

The original such compound was derived from the chi-ral biomolecule phenylalanine [196 197] The first highlyenantioselective organocatalytic Diels-Alder reaction usinga chiral organocatalyst was reported in MacMillanrsquos pio-neering work where the activated iminium ion formedthrough condensation of the imidazolidinone and an 120572120573-unsaturated aldehyde reacted with various dienes to give[4+2] cycloadducts in excellent yields and enantioselectivi-ties Ahrendt et al reportedmany other asymmetric reactionssuch as the 13-dipolar cycloadditions Friedel-Crafts alky-lations 120572-chlorinations 120572-fluorinations and intramolecularMichael reactions usingMacMillanrsquos organocatalysts [96 150198ndash201]

Ouellet et al also reported the combination of imida-zolidinone organocatalyst and Hantzsch ester to facilitatethe first enantioselective organocatalytic hydride reductionof 120572120573-unsaturated aldehydes (Scheme 8) [202 203] Thisimitated naturersquos stereoselective enzymatic transfer hydro-genation with NADH cofactor

Noncovalent interaction is a structure-reactivity andconformation deciding factor which requires immediateattention for understanding organocatalysis [204] Of specialinterest would be the identifying and understanding of othernoncovalent interactions such as charge transfer [205] pndashp stacking immobilization [206] and adsorption or entrap-ment of organocatalysts in nanomaterials [207]

Homogeneous and HeterogenizedMacMillanrsquos OrganocatalystAn asymmetric Diels-Alder reaction was catalyzed with highefficiency and recyclability by a soluble ldquoself-supportedrdquochiral organosilica polymer with embedded imidazolidinonecatalytic moieties [208]

76 Chiral Phosphoric Acids BINOL derived phosphoricacids catalyze nucleophilic addition reactions to imine sub-strates A direct Pictet-Spengler reaction was reported usinga geminally disubstituted tryptamine organocatalyst to formisoquinolines in excellent yield and enantiomeric excess[209] Phosphoric acid catalyzing the reduction of an iminewith a Hantzsch ester in good enantiomeric excess was firstlyreported by Rueping et al Hoffmann et al reported animprovement to this methodology [210 211]

Storer research group reported a one-pot reductive ami-nation of a range of methyl ketones and aryl amines [212]Reductive amination of 2-butanone over silylated phosphoricacid MacMillan TiPSY catalyst was obtained with goodenantiomeric excess

Zhou and List published on the use of chiral Broslashnstedacid (R)-TRIP for highly enantioselective synthesis of phar-maceutically relevant 3-substituted cyclohexylamines from26-diketones wherein the achiral amine substrate acceleratesthe cascade reaction before getting incorporated into the finalproduct (Scheme 9) [213]

Rowland et al reported VAPOL derived phosphoric acidcatalyzed addition of sulfonamides to BOC protected arylimines and protected aminals in excellent enantioselectivities[214]

The (R)-TRIP catalyzed the aza-Diels-Alder reaction ofaldimines with Danishefskyrsquos diene to yield piperidinonederivatives with high enantioselectivity Addition of aceticacid was found to improve both reactivity and enantiose-lectivity [215] Six chemical bonds five stereogenic centersand three cycles were formed in one-pot four-componentUgitype reaction catalyzed by a chiral BINOLderived phosphoricacid [216] BINAP is one of the earliy commercially appliedligands in industrial catalysis [217] Amicroporous recyclableheterogeneous catalyst offering excellent enantioselectivitywas made from a 111015840-binaphthalene-221015840-diol (binol) derivedphosphoric acid chloride and was found as active as thecorresponding homogeneous catalyst [218]

Journal of Catalysts 13

O

O

Ph

OEt HH

Ph

HN

OEt

i-Pr

i-Pr

i-Pri-Pr

i-Pr

i-Pr

O

OP O

OH

EtO2C CO2Et

CyclohexaneMS 5 A 50∘C

NH2

(R)-TRIP (10mol)

82 dr = 24 1 er = 98 21 22

Scheme 9 Zhou and List [213]

NO

N NHH N

HO

S

N

H R

BocO-PrTBS-O

Pr-O

HN

Boc

5mol catalyst+

t-Bu

t-Bu t-Bu

(2) TFA 2min(1) Toluene minus30∘C 48hr

86ndash98 ee

Scheme 10

HO OH

O O

Figure 6

77 Chiral Diols Huang et al reported on use of TADDOLs(Figure 6) as Broslashnsted acid organocatalysts in highly stereos-elective hetero-Diels-Alder reactions [219]

The 120572-amination of carbonyl compounds has also beenaccomplished by using the 1-naphthyl TADDOL derivative asa Broslashnsted acid organocatalyst [220] McDougal and Schausreported asymmetric Morita-Baylis-Hillman reaction that

is the addition of cyclohexenone to different aldehydescatalyzed by octahydro-BINOL derived Broslashnsted acid [221]

78 JacobsenThioureas ProfessorsVachal and Jacobsen iden-tified chiral thioureas (Figure 7) as versatile and effectiveorganocatalysts 1mol of the thiourea was reported to havecatalytic activity in the hydrocyanation (Strecker reaction) ofboth aldimines and ketoimines with very high enantioselec-tivities [222]

Imine hydrophosphonylation particularly effective withelectron-withdrawing ester substituents on the phosphatetook place in the presence of 10mol of the catalyst [223]Mannich reactions of BOC protected imines have also beenreported (Scheme 10) [224] with excellent yields and enan-tioselectivities and show heterocyclic substrate tolerance

A variant of thiourea organocatalyst was found to catalyzethe cyanosilylation of ketones and aldehydes in high yieldsand enantiomeric excesses [225] Thiourea organocatalystwas put to use in the acyl-Pictet-Spengler reaction to formtetrahydro-120573-carbolines [226] The acyl-Mannich reactionproviding a route to enantioenriched heterocycles from

14 Journal of Catalysts

N N N

H H NO H

HO

O

O

O

t-Bu

t-Bu

t-Bu

Figure 7

aromatic starting materials and trichloroethyl chloroformate(TrocCl) is also catalyzed by the thiourea organocatalyst[227] Bifunctional thiourea-base catalyzed double-Michaeladdition of benzofuran-2-ones to dienones is reported forthe synthesis of optically enriched spirocyclic benzofuran-2-ones [228] In another interesting example benzoylthiourea-pyrrolidine catalyst was synthesized and used in the asym-metric Michael addition of ketones to nitroalkenes [229]

Primary amine-thioureas were improvised to catalyzedifficult Michael reactions synthesizing (S)-baclofen (R)-baclofen and (S)-phenibut [230]

79 Cinchona Alkaloids The cinchona alkaloids catalyzemany useful processes with high enantioselectivities Asym-metric phase transfer catalysis (PTC) presents a ldquogreenrdquoalternative to homogeneous synthetic organic chemistrymethodologies Cinchona alkaloids are synthetically mod-ified for their usage in asymmetric PTC O-Alkyl N-arylmethyl derivatives of cinchona alkaloid led highly enantiose-lective alkylation of glycine imines to generate 120572-amino acidderivatives And for the same reaction dimeric cinchonaalkaloid obtained 97ndash99 enantiomeric excess [231 232]Cinchona alkaloids deprotonate substrates with relativelyacidic protons forming a contact ion pair between the result-ing anion and protonated amineThis interaction generates achiral pool around the anion and facilitates enantioselectivereactions with electrophiles The control over the formationof quaternary asymmetric centers is essential to obtain highenantiomeric excesses The 120572-functionalization of ketones(Scheme 11) by the addition of TMSCN to the correspondingcyanohydrin in excellent yield and enantiomeric excess iscatalyzed by the (DHQD)

2AQN catalyst [233]

Increasingly remote stereocenters are being targeted inasymmetric aminocatalysis Organocatalytic allylic amina-tion presents an alternative to the conventional palladiumcatalyzed methodology Amination at the remote 120574-positionusing (DHQ)

2PYR forms highly functionalized amine com-

pounds [234]Bella and Joslashrgensenrsquos reported the first enantioselective

conjugate addition of 120573-diketones to both aromatic andaliphatic alkynones using (DHQ)

2PHAL catalyst [235] Cin-

chona based primary amine catalysis is found to offer high

efficiency and reliability in the asymmetric functionalizationof carbonyl compounds [236 237] Organocatalysts derivedfrom cinchona alkaloids function as Lewis base catalyst inthe cyclizations of allenoates with electron deficient olefinsand imines and emerged as important synthetic tool inthe preparation of biologically active and pharmaceuticallyinteresting cyclic compounds including natural products[238] Recently cinchona thioureas have been reported forthe first time as catalysts in the area of asymmetric oxi-dations [239] Cinchona and cinchonidine derived catalystsperform asymmetric direct aldol reaction of pyruvic aldehydedimethyl acetal with isatin derivatives [240] Likewise thereare various other examples reported where cinchona or itsvariants are used as organocatalysts for syntheses of variousbiologically important molecules [241ndash246]

710 Maruoka Phase Transfer Catalysts The chiral catalystforms a host-guest complex with the substrate and shuttlesbetween the standard organic solvent and a second phaseexample catalytic enantioselective enolate alkylation [72]As we know chiral quaternary ammonium catalysts can beuseful in asymmetric synthesis Kitamura et al reported C2-symmetric ammonium salts catalyzing monoalkylation ofglycine derived Schiff bases with alkyl halides to synthesize120572-alkyl-120572-amino acids under remarkably low catalyst loadings[247ndash249]

Utilizing the solubility of aqueous quaternary ammoniumsalts into organic solvents professor Maruoka developedspirotype chiral ammonium salt with two binaphthyl ringsas a novel chiral phase transfer catalyst Figure 8 depicts theorganocatalyst for direct asymmetric aldol reaction of 120573-hydroxy-120572-amino acid derivative

711 Oxazaborolidines Chiral oxazaborolidines (known asCBS oxazaborolidines after Corey Bakshi and Shibata)catalyze the reduction of prochiral ketones imines andoximes to produce chiral alcohols amines and amino alco-hols respectively in high yields and excellent enantiomericexcesses The chiral Lewis acid generated from o-tolyl-CBS-oxazaborolidine after protonation with trifluoromethanesul-fonimide is very useful in the enantioselective Diels-Alderreaction (Scheme 12) [250ndash256]

Journal of Catalysts 15

O NC OTMSN

OH

N

N

OH

N

OO

2 to 20mol catalyst

TMSCN CHCl3

OC2H5

OC2H5

OC2H5

OC2H5

H3CO

C6H5C6H5

OCH3

Scheme 11 Tian et al [233]

OO

O

OO

II

CH3CH3

CH3

H3C

H3C TIPSOTIPSO

H

H

H

PhPh

NB

minus

+

+

(CF3SO2)2N

20mol catalyst

16hoursDichloromethane minus78∘C

Scheme 12 See [250ndash256]

712 Shi Epoxidation Catalyst Tu et al reported a fructosederived ketone in efficient asymmetric epoxidation of trans-olefins (Scheme 13) [257] Epoxidation catalyst is able toepoxidize trans-alkenes and certain cis-alkenes with good toexcellent yields and selectivities [258 259] Marigo et alrsquosgroup reported an asymmetric organocatalytic epoxidationof 120572 120573-unsaturated aldehydes with environmentally friendlyoxidant hydrogen peroxide [260]

713 N-Heterocyclic Carbene (NHC) as Organocatalysts

7131 Rovis Catalyst The conjugate addition of an aldehydeto an 120572120573-unsaturated compound (Stetter reaction) is apractical methodology for the construction of 14-dicarbonylcompounds bearing quaternary stereocenters Triazoliumsalt in the presence of a base functions as an N-heterocycliccarbene organocatalyst (Figure 9) in highly enantioselectiveintramolecular Stetter reactions [261 262]

7132 Bode Catalyst Bodersquos studies on NHCs (Figure 10)mainly involve catalytic generation of reactive speciessuch as enolates homoenolates and activated carboxylates

N-Mesityl substituent on an imidazolium or triazoliumNHCprecursor generates highly enantioselective annulations fromsimple starting materials under mild reaction conditions[263 264] In an interesting example the catalysts facilitatehighly enantioselective cyclopentene forming annulations ofsimple enals and activated enones [265] Redox esterificationsand amidations of 120572-functionalized aldehydes using achiralcatalyst are also reported [266] Uniting unique activationmodes of N-heterocyclic carbene (NHC) catalysts with theconcept of domino reactions a new fast-growing field cameinto the spotlight in last couple of years or so [267ndash269]

Domino Michaelaldol reaction between 2-mercapto-quinoline-3-carbaldehydes and enals was catalyzed by di-phenylprolinol silyl ether producing 2H-thiopyrano[23-b]-quinolines in excellent yields and enantioselectivities [270]Zhao et al reported studies on ldquocooperative NHC andrutheniun redox catalysisrdquo in the oxidative esterificationof aldehydes [271] Blanc et al reported NHC mediatedorganocatalytic one-pot allylstannation to generate syn-diols[272] With enals as starting aldehydes elegant cascadeprocesses have been developed using oxidative carbene catal-ysis [273ndash276] Over the last few years there are examplesreported in literature where various organocatalysts rally

16 Journal of Catalysts

O

Oxone

OO

O

O

OO

R1 R1

R3

R3

R2 R2H2OCH3CN

Scheme 13

F3C

N+

F3C

Brminus

CF3

CF3

Figure 8 See [176]

N

O

N

N

F

F

F

F

F

+BF4minus

Figure 9

domino reactions and attract their application in organicprocesses in industries [174 175 180 181 183]

Apart from the aforementioned organocatalysts thereare other organic systems which upon appropriate acti-vation function as catalysts in useful asymmetric synthe-ses [155ndash157] 12-Dicarbonyl compounds because of theiradjacent multiple reactive centers upon activation act asefficient pronucleophiles in asymmetric organocatalyzed

N

O

NN+

Clminus

Figure 10

sequential or domino transformations including CndashC or CndashN bond formation [277] Cyclopropenone catalyzed con-version of aldoximes and primary amides into nitriles ina one-pot mild reaction widens the scope of the utiliza-tion of cyclopropenones in organic synthesis [278] Thefirst asymmetric organocatalytic synthesis by phosphinecatalyzed [3+2] cycloaddition of allenoates onto fullereneis reported to yield enantiomerically pure carbocyclicfullerene derivatives under mild conditions [279] A new[3+2] cycloadditioncycloreversion strategy for organocat-alytic and thermally allowed carbonyl-olefin metathesis isreported [280] Recently a strong evidence for halogenbond based organocatalysis is reported for the reactionof 1-chloroisochroman with ketene silyl acetals [281] Acidcatalyzed asymmetric acetalizations of aldehydes are alsodescribed [282] beta-Isocupreidine catalyzed the enantios-elective Morita-Baylis-Hillman reaction of maleimides withisatin derivatives to form 3-substituted 3-hydroxyoxindolederivatives [283 284]

Recent advances in asymmetric catalysis resulted in uti-lizing the less discussed electrophilic properties of iminiumtype intermediates in complex annulations of indoles [285286] and also pyridines [287 288] Shibatomi and Narayamadiscussed the catalytic enantioselective 120572-chlorination of car-bonyl compounds and stereospecific substitution reactions ofthe resulting optically active alkyl chlorides [289]

Though there is no relation between the developmentof two different fields of organocatalysis and gold catalysis

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

[1] ldquoOur Common Future Report of the World Commissionon Environment and Development United Nations (UN)Commission on Environment and Development (BrundtlandCommission) 1987rdquo Published as Annex to General Assem-bly document A42427 Development and International Co-operation Environment August 1987

[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

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[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

[17] J R Anderson and K C Pratt Introduction To Characterisationand Testing of Catalysts Academic Press Sydney Australia1985

[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

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Analytical Methods in Chemistry

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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

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Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

Journal of Catalysts 3

According to the state of aggregation in which the catalystsact there are two main groups homogeneous catalysts andheterogeneous catalysts Homogeneous catalysts are well-defined chemical compounds or coordination complexeswhich together with the reactants are molecularly dispersedin the reaction medium and carry out processes in a uniformgas or liquid phase Heterogeneous catalysis takes placebetween different phases Generally the catalyst is in solidstate and the reactants are gases or liquids The immobilizedcatalysts obtained by attaching homogeneous catalysts tosolid are in between In supported catalysts the catalyticallyactive substance is applied to a support material that hasa large surface area and is usually porous Arguments forand against shall always be made while discussing the meritsand limitations of individual groups of catalysts for theirrespective applications in industries

3 Application of Catalysis

Catalysis has played a pivotal role in the success of thechemistry industry in the twentieth century More than 90of chemical manufacturing processes in the world utilizecatalysts [7 8] Historically the first industrially appliedcatalytic process was for the hydrogenation of oils and fatsto produce margarine using finely divided nickel as catalystThus heterogeneous catalysis was applied first industriallyThe issue of metal leaching and the avoidance of tracecatalyst residues are very important from environmentalhealth point of view All the basic raw materials or buildingblocks for chemicals are manufactured by very important setof heterogeneous catalytic reactions (Table 1) [8] Althoughcatalysts are not consumed by the reaction itself they may beinhibited deactivated or destroyed by secondary processesThe solid-state catalyticmaterials are themost important typeof catalysts

Implementation of ldquocleanrdquo and ldquogreenrdquo chemical technol-ogy in industries may help address the problem of envi-ronmental degradation besides producing useful chemicals[9ndash12] Some catalysts also present important technology inthe prevention of emissions for example catalytic converterfor automobiles Keeping in mind the fragile ecosystem andthe importance of preserving the environment the hetero-geneous catalysts are tested in the pollution abatement [1314] and to remove aqueous organic wastes volatile organiccompound and vehicular primary emissions such as COunburned hydrocarbon NOx and soot

Heterogeneous catalysis which takes place between dif-ferent phases has now grown into an important branch ofscience [8ndash12 15] Exciting new opportunities are emergingin this field based on nanotechnology approaches Henceresearch efforts are being directed to develop chemistry ofnanomaterials and their applications in catalysis for devel-oping cost-effective selective energy sufficient ecofriendlyand environmentally benign synthetic processes for indus-tries Though this involves a great scientific economic andtechnological challenge it is essential to a sustainable andhealthy way of life

The petroleum and fine chemical and pharmaceuticalindustries mostly rely on catalysts to produce everything

from natural gasfuels to various commodities [15 16] Thereare a variety of new challenges in creating alternative fuelsreducing harmful by-products in manufacturing cleaningup the environment and preventing future pollution deal-ing with the causes of global warming and creating safechemicals and pharmaceuticals Thus catalysts are needed tomeet these challenges of health safety and environmentalenergy-related and economic issues but their complexityand diversity demand an insight on the way catalysts arestudied designed and used This could come into realityonly through the application of an interdisciplinary approachinvolving new methods for synthesizing and characteriz-ing molecular and material systems Research in heteroge-neous catalysis demands the cooperation of scientists fromanalytical chemistry solid-state chemistry (nano)materialschemistry physical chemistry surface science computationaland theoretical chemistry reaction kinetics and mecha-nisms reaction engineering and so forth Opportunities tounderstand and predict how catalysts work at the atomicscale are now appearing made possible by breakthroughsin the last decade in computation measurement techniquescharacterization spectroscopy and imaging and especiallyby new developments in surface-reactivity studies modelcatalyst design and evaluation [16 17] Surface science andspectroscopy has its prominent role in analysing surfacereaction chemistry on the catalyst [18 19]

Fermentation of sugar to ethanol and the conversionof ethanol to acetic acid catalyzed by enzymes were anexample of catalysis in antiquity Off late enzymatic catalysisis considered as a separate branch of (biological) catalysis It isthe most recent branch widely included in many commercialapplications [20 21] Enzymes are also highly active undermild conditions such as temperature pressure and pHwhichmake them easier to work with on a small scale but are alsomore appealing on an industrial scale on a cost and efficiencybasis Another benefit is that reactions are preferentiallycarried out in aqueous media therefore providing a ldquogreenerrdquoroute Not to forget the development of water based organictransformations is also an area of rapidly growing importancein chemistry [22 23]

The homogeneous catalysis prior to the recognition ofthe effects of heterogeneous catalysts started with the actionof nitrous oxides in the lead chamber process Althoughthe fundamental processes for refining petroleum and itsconversion to basic building blocks are based on heteroge-neous catalysts many important value-added products aremanufactured by homogeneous catalytic processes (Table 2)[12] Homogeneous catalysts have been well researchedsince their catalytic centers can be relatively easily definedand understood but difficulties in separation and catalystregeneration prevent their wider use [12 24ndash28] The mostwidely used homogeneous catalysts are simple acids orbases which catalyze well-known reactions such as esterand amide hydrolysis or esterification The market share ofhomogeneous catalysts is estimated to be only ca 10ndash15Many of the benefits of homogeneous catalysts especiallyhigh selectivity arise from tailored made catalysts involvingtransition metals (or lanthanides) and appropriate ligandsSuch catalysts are inexpensive enough that they can be

4 Journal of Catalysts

Table 1 List of some of the industrially applied reactions and catalysts

Reaction Catalyst Inventor (Year)Sulphuric acid (leadmdashchamber process) NO

119909Clement Desormes (1806)

Chlorine production by HCl oxidation CuSO4 Deacon (1867)Nitric acid by NH3 oxidation Pt Rh nets Ostwald (1906)Fat hardening Ni Normann (1907)

Ammonia synthesis (H2 + N2) Fe Mittach Haber Bosch (1908)Production 1913 BASF

Hydrogenation of coal to hydrocarbons Fe Mo Sn Bergius (1913) Pier (1927)Methanol synthesis from CoH2 ZnoCr2O3 Mittach (1923)Hydrocarbons from COH2 (motor fuels) Fe Co Ni Fischer Tropsch (1925)Alkylation of olefins to gasoline AlCl3 Pines (1932)Cracking of hydrocarbons Al2O3SiO2 Houdry (1937)Cracking in a fluidized bed Aluminosilicates Lewis Gilliland (1939)Ethylene polymerization at low pressure Ti compounds Ziegler Natta (1954)Hydrogenation isomerization hydroformylation Rh- Ru complexes Wilkinson (1964)

Methanol carbonylation to acetic acidCoiodide BASF (1960)Rhiodide Monsanto Co (1966)Iridium BP Chemicals Ltd (2000)

Asymmetric hydrogenation Rhchiral phosphine Knowles (1974)Three-way catalyst Pt Rhmonolith General Motors (1974)Methanol conversion to hydrocarbons Zeolites Mobil Chemical Co (1975)Alpha-olefins from ethylene Nichelate phosphine Shell company (1977)Sharpless (epi) oxidation TIROOHTartarate May Baker Upjohn ARCO (1981)Selective oxidations with H2O2 TS-1 (titanium silicate) Enichem (1983)Hydroformylation Rhphosphine Rhone-Poulene-Ruhrchemie (1984)Polymerization of olefins ZirconoceneMAO Sinn Kaminsky (1985)Selective catalytic reduction (SCR) V W Ti oxidesmonolith 1986

Table 2 Differences between homogeneous catalysts and heteroge-neous catalysts

Homogeneous catalysts Heterogeneous catalystsSame phase as reaction medium Solid phaseDifficult separation Easily separableNo recyclability Recyclability and regenerationOften high rates of reaction Low rates of reactionNo diffusion control Diffusion controlRobust to poisoning Poisoning deactivationHigh selectivity Low selectivityShort life Long catalytic lifeMild conditions Energy-consuming processWell understood mechanism Poor mechanistic understanding

neutralized easily separated from organic materials anddisposed of This contributes to the huge quantity of aqueoussalt waste generated by industry Organometallic catalysts arecurrently widely used in industry but the search for improvedefficiencies enantioselectivities or recycling is still a matterof intense researches [29ndash33] It is true that homogeneouslycatalyzed processes such as hydroformylation carbonylationoxidation hydrogenation metathesis and hydrocyanationcontribute with millions of tons to the bulk chemicals but

on the other hand the progress of homogeneous catalysisis also going on with fine chemicals [25 33] In spirit ofthat the beginning of this century saw the renaissance oforganocatalysis presenting an environmental advantage overmetal based catalysts for stereoselective or asymmetric syn-thetic methodologiesThe absence of metal in organocatalystbrings an undeniable advantage considering the principles ofldquogreen chemistryrdquo and the economic point of view (Tables 3and 4)

Understanding catalytic systems involve study of struc-ture state and composition of catalysts and the phase inwhich they perform And for this one needs to understandchemistry of molecules and materials useful as catalysts andor catalyst carriers

4 Materials for Catalysis

The diversity of research field connected to the chemistry ofmaterials is significant for their applications in many areasincluding adsorption catalysis electrochemistry and surfacescience Nanoparticles [34] metal oxide and mixed metaloxides [35ndash38] prepared by simple methods are useful cata-lysts Research involving metal-organic frameworks [39 40]mesoporous silica [41ndash43] microporous or open-frameworkinorganic [44ndash46] andor mesopore modified [47] materials

Journal of Catalysts 5

Table 3 Comparison among organometallic catalysts enzyme catalysts and organocatalysts

Organometallic catalyst Enzyme catalyst Organocatalyst

Wide substrate scope high catalyticactivity involving tedious processpotential heavy metal pollution

Limited substrate scope highselectivity and catalytic activity

usually single enantiomer

Robust inexpensive readily available nontoxic inert towardmoisture and oxygen method especially attractive for the

preparation of compound that do not tolerate metal contamination(pharmaceutical products)

Table 4 Advantages and disadvantages of organocatalysts

Advantages DisadvantagesEasy preparation or availability High catalyst loadingEasy handling inert towards moisture(water) and air (oxygen) Relatively premature field

Easy scale-upNo metal contaminationEasy screeningUseful in complex (steric) reactions

has steadily increased following the widespread utility ofaluminosilicate zeolites [48ndash51] titanosilicates [52 53] andaluminium phosphates [54 55]

In industries research endeavours are mainly devotedtowards the study and development of zeolites or zeoliticmaterials with several attractive features such as cat-alytic active site(s) large surface area zeolitic pore wallsand pore size control The synthesis and characteriza-tion of the crystalline aluminosilicate materials with tun-able meso-microporosity and their strong acidity havepotentially important technological implications for shape-selective catalytic reactions ion exchange and adsorption oforganic compounds [56ndash58]Thepore diameters can be finelychosen tuned and utilized for exhibiting shape-selectivecatalysis depending on the molecular shapesize of organicreactant and product The widespread interest has beendeveloped in the zeolitic science towards the developmentand discovery of zeolites with desired characteristics sinceconventional zeolites lack fine tuning of their properties toacidbase and redox or bifunctional or multifunctional prop-erties Organic functionalization adds new catalytic functionsto zeolites [59]

Zeolites are microporous crystalline aluminosilicateswith unique properties used for many processes Zeolitespossess acid sites that are associated with the tetrahedralaluminium atoms in their framework and therefore theamount of acidity depends on the aluminium content ofthe zeolite Zeolite acid catalysts have wide application inindustrial processesThe introduction of Y-zeolites to replaceamorphous silica-alumina in fluidized catalytic cracking(FCC) and in hydrocracking processes in the early 1960rsquos wasa breakthrough application in acid catalysis With the everincreasing research efforts in this area leading to discoveriesof new structures and modification schemes by academicand industrial laboratories the potential of solid acids hasevolved tremendously However with the exception of theZSM-5 Mordenite and to some extent Beta zeolite very few

of these structures have been applied in industrial processesto any significant extent Yet one can account for relativelyfew applications to the huge number of new materialsintroduced Notable examples are the reported uses of SAPOsin lube dewaxing and in natural gas to olefin technologiesand MCM-22 in aromatics alkylation The zeolite structureswith large-porebimodal porosity and tunable acidity canbe a remarkable benefit for catalytic processes in industriesWithin industrial catalysis there are constant innovation andchanging approaches to provision of selective economicallyviable and environmentally benign processes

Recently enormous growth in the chemical diversity ofinorganic materials with transition-metal incorporation innew compositional domains has also been explored dueto their potential application in adsorption and catalysisInorganic polymers transition metal phosphates and metal-organic frameworks [39 40] with novel catalytic electronicmagnetic and unique structural properties are particularlypromising candidates [60ndash64] The mesoporous structurewith strong acidity can be a remarkable benefit for catalyticreactions involving large organic molecules in which diffu-sion constraints andor adsorption of reactantmolecules ontothe strong acid sites are the main concern A lot has beenreported about the pathways to developmesostructured silica[65] In terms of surface functionalization the performanceof mesoporous silica has been polished by several methodssuch as metal incorporation [66] metal deposition [67]grafting by organic functional groups [68] and immobiliz-ing metal complex [69] New approaches to synthesis andcharacterization of bimodal that is micro-mesoporous andor meso-macroporous materials might assist us in under-standing the phenomena of diffusion confinement effectsselectivity and so forth [47]

5 Organocatalysis A NovelSynthetic Philosophy

The term ldquoorganocatalystrdquo is a concatenation of the wordsldquoorganicrdquo and ldquocatalystrdquo The definition corresponds to a lowmolecular weight organicmolecule which in substoichiomet-ric amounts catalyzes a chemical reactionThe organocatalystcould be achiral or chiral and could be composed of CH N S and P Organocatalysis has several advantages notonly because of its synthetic range but also for the economicreasons The absence of metal in organocatalyst brings anundeniable advantage considering both the principles ofldquogreen chemistryrdquo and the economic point of view (Figure 3)

Nowadays organocatalysis is one of the hot researchtopics in advanced organic chemistry It is a novel syn-thetic philosophy and mostly an alternative to the prevalent

6 Journal of Catalysts

N

H

L-ProlineN

N

DMAP

OH

Nobin

N

NO

H

MacMillanrsquos catalyst

O

N

HO N

Quinine

CO2H

NH2

∙ ∙

Figure 3 Few famous examples of organocatalysts L-proline DMAP quinine and MacMillanrsquos catalyst

transition metal catalysis Organocatalysts are often basedon nontoxic organic compounds originating from biologicalmaterials Organocatalysts can be Lewis bases Lewis acidsBroslashnsted bases and Broslashnsted acids Most of the organocatal-ysis reported so far are explained by Lewis base mechanismThe Lewis base mechanism can be simplified as follows

Step I Lewis base for example cinchona alkaloidinitiates catalysis via a nucleophilic addition to ordeprotonation of the substrateStep II the chiral intermediate undergoes reactionStep III separation of product(s) from the catalystoccursStep IV regeneration of the catalyst and its availabilityfor a new catalytic cycle occurs

There are many organocatalytic reactions that need a secondmechanism to explain the catalytic cycle involved This iscalled bifunctional organocatalysis in which the organocata-lyst possesses not only a Lewis base (nitrogen or phosphorusatom) but also a Broslashnsted acidic site There is a lot to be donein redox catalysis and in exploitation of the synergetic effect ofdifferent catalytic active sites within one organic compoundor material

Some advantages of organocatalysts include the following

(i) Reactions performed by organocatalysts have poten-tial application in large scale production in industries

(ii) Scope organic reactions occur which are not inpractice and not possible by other forms of catalystsfor example asymmetric synthetic processes

(iii) PriceAvailability Low cost alkaloids natural aminoacids L-proline tartaric acid and so forth are easilyavailable and are economically attractive

(iv) Recycling issues immobilization of the catalyst is thesimplest way to recover it

(v) Some of the examples include bioderived andbiodegradable organocatalysts

(vi) Organocatalysts work at mild reaction conditions(vii) Sometimes the final products of reactions contain

high levels of metal contamination derived from cat-alyst degradation phenomena which pose a seriousdrawback if the metal is toxic for pharmaceutical andfood industries Absence of transition-metal bringsorganocatalysis at the heart of greening chemistry

Organocatalysis can be categorized into our different typesas follows

Type-I activation of the reaction based on the nucle-ophilicelectrophilic properties of the catalyst is done(Scheme 1)

Type-II organic molecules form reactive intermedi-ates The chiral catalyst is consumed in the reactionand requires regeneration in parallel catalytic cycle asit is reported in Scheme 2

Type-III phase transfer reactions occur The chiralcatalyst forms a host-guest complexwith the substrateand shuttles between the standard organic solvent anda second phase

Journal of Catalysts 7

O

O

O

O

OOH

100

N

H

3mol L-proline

DMF 20∘C 20h

CO2H

Scheme 1 Hajos and Parrish [70]

O

O

OOO

O

O

30mol catalyst

30 H2O2 (3 equivalent)

CH3CNndashK2CO3

R1R3

R2

R1R3

R2

Scheme 2 Shu and Shi [71]

Catalytic enantioselective enolate alkylation(Scheme 3) occurs

Type-IV molecular-cavity-accelerated asymmetrictransformations occur in which the catalyst mayselect from competing substrates depending on sizeand structure criteria (Scheme 4)

6 Discovery and the History ofOrganocatalysis

Liebigrsquos synthesis of oxamide from dicyan and water is thefirst organocatalytic reaction reported [74] Acetaldehydewasfurther identified to behave as the then-named ldquofermentrdquonow called as enzyme Dakin in 1909 demonstrated that ina Knoevenagel type condensation between aldehydes andcarboxylic acids or esters with active methylene groups theamine catalysts could be mediated by amino acids [75]Langenbeck is remembered for developing enamine typereactions and the application of simple amino acids andsmall oligopeptides as catalysts [76ndash78] Natural products inparticular strychnine brucine and cinchona alkaloids andamino acids (including short oligopeptides) were amongthe first organic catalysts tested [79 80] Though the fieldof small-molecule catalysts seems very simple there are

evidences that prove their pivotal role in synthesis of buildingblocks for life L-Alanine andL-isovaline capable of catalyzingcertain CndashC bond formation reactions had been found onmeteorites [81]

An asymmetric transformation with an organic moleculewas published in 1912 by Bredig and Fiske [82] Pracejusapplied cinchona alkaloids in the asymmetric conversionof ketenes to (S)-methyl hydratropate [83 84] An initialresearch byYamadaampOtaniwas important too [85]The sev-enties brought anothermilestone Hajos and Parrish reporteda L-proline catalyzed Robinson annulation in excellent enan-tioselectivities [70 86 87] Eder et al reported organocat-alytic aldol reactions in good enantioselectivities [88] Tosummarize in 1970s Hajos and Parrish and independentlyEder Sauer and Wiechert published a series of papers andpatents involving such organocatalytic transformations Theasymmetric synthesis of enediones useful building blocksin natural product total syntheses was achieved (S)-Prolineinduced the formation of (S)-enediones

Two mechanisms [89] were proposed (1) involving theformation of a carbinolamine intermediate followed by thedisplacement of the proline moiety by nucleophilic attackof the enol from the side chain ketone (2) involving anenaminium intermediate acting as a nucleophile in the CndashCbond formation with concomitant NHsdot sdot sdotO hydrogen trans-fer Wynberg firstly published various 12 and 14 additionscatalyzed by cinchona bifunctional organocatalysis [90ndash92]

8 Journal of Catalysts

N

O

Ph

Ph

Ph

Ph

N

O

OO

O

81 96 eeO

O

O

O

H N

Chiral quaternary ammonium catalyst10mol catalyst

CH2Cl2BrH2C

Ot-Bu

Ot-Buminus78

∘C 24h

+

Brminus

CsOHmiddotH2O

Scheme 3 Corey et al [72]

O

BOCHN BOCHN

OO OH

Nu

OH

(2) Nu

(1) Polymer

HO

N

HN

HO

O

O

OH

NO2

NO2

+

Scheme 4 Sellergren et al [73]

All these research endeavours were not carefully looked intotill List et al reported in 2000 proline catalyzed aldol reactionin good enantiomeric excesses [93 94]

Asymmetric catalysis constitutes one of the most impor-tant subjects in synthetic organic chemistry Asymmetricsynthesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the application of such methodologies inchemical industry is rather limited due to the high cost ofchiral ligands and noble metals used in such transformationsMoreover the pharmaceutical entities and food industryproducts do not tolerate a contamination of even traces ofany such metals for that matter Synthesis of chiral drugshas a major financial impact in pharmaceutical industrieson a global scale Different enantiomers or diastereomers ofa molecule often have different biological activity Most ofthe drugs might be soon sold as single enantiomers in thecoming years There is a huge demand for organocatalystsleading to 100 yield 100 ee of the desired product Theneed from chemical industry especially pharmaceutical forreliable asymmetric transformations of molecular skeletonsis higher than ever Therefore asymmetric organocatalysisis in a process of attaining maturity into a very powerful

practical and broadly applicable methodological approach inthe catalytic asymmetric synthesis

7 Some Examples and Developments inCatalyst Structural Variants

Following are the famous examples of organocatalysts

71 Proline and Derivatives The proline catalyzed Robinsonannulation was one of the earliest examples of an enantios-elective reaction using an organic catalyst [85] This aminoacid contains both a nucleophilic secondary amino groupand a carboxylic acid moiety functioning as a Broslashnstedacid The availability of proline in both enantiomeric formsbrings advantages over enzymatic methods Arguably thefirst example of proline catalyzed asymmetric aldol reactionis reported by Hajos and Parrish [70 86 87] The Wieland-Miescher ketone is a useful synthetic building block forwhich a classical asymmetric procedure using (S)-prolinewas published forty years ago [88] It is quite significant thatthe first efficient organocatalyzed asymmetric reactions weredescribed by Hajos amp Parrish [86 87] and by Eder et al [88]

Journal of Catalysts 9

both teams from pharmaceutical companies (Hoffmann-la-Roche and Schering) The asymmetric synthesis of theWieland-Miescher ketone is also based on proline andanother early application was one of the transformations inthe total synthesis of erythromycin by Woodward et al [95]Proline is recognized as a versatile organocatalyst of thesetimes (Scheme 5)

In fact the renewal of proline catalyzed transformationsin early 2000 by D W C MacMillan Carlos F Barbas IIIand Benjamin List saw the renaissance of the concept and itwas the starting point of the word ldquoorganocatalysisrdquo ProfessorAhrendt group reported the first enantioselective organocat-alytic Diels-Alder reaction [96] Proline was identified asan effective organocatalyst for asymmetric aldol reaction[97] The catalytic asymmetric 120572-alkylation of aldehydeswas reported by Vignola and List [98] This transformationhad been accomplished with the help of covalently attachedauxiliaries 120572-Methyl L-proline exhibits higher enantioselec-tivities and improved reaction rates when compared to L-proline In recent years proline especially L-proline hasbeen used to catalyze essential transformations used in thefine chemical and pharmaceutical industries such as thedirect asymmetric aldol reactions [99ndash107] Diels-Alder reac-tions Michael reactions [108ndash115] Mannich reaction [116ndash122] Multicomponent reactions [123 124] and 120572-amination[125] 120572-aminoxylation [126ndash128] 120572-oxyaldehyde dimer-ization [100] 120572-functionalization of carbonyl compounds[129] and 120572-alkylation of aldehydes [130] Organocat-alytic cyclopropanation reactions were typically performedusing catalyst-bound ylides However Kunz and MacMil-lan demonstrated that activation of olefin substrates usingcatalytic (S)-(minus)-indoline-2-carboxylic acid is a viable routefor the formation of highly enantioenriched cyclopropanes[131]

Prof K A Joslashrgensen has made an importantbreakthrough in asymmetric synthesis by developing (R)-and (S)-120572120572-bis[35-bis(trifluoromethyl)phenyl]-2-pyrroli-dinemethanol trimethylsilyl ether as excellent chiral organ-ocatalysts in the direct organocatalytic 120572-functionaliza-tion of aldehydes Diarylprolinol silyl ether reagents werefound to catalyze CndashC CndashN CndashO CndashS and CndashHal bondforming reactions [132ndash138] Cascade or domino reactionsswiftly construct complex biologically important compoundsand minimize waste and also the laboratory operations [139]Endersrsquo group developed proline derived organocatalyst fora chemo- diastereo- and enantioselective three-componentdomino reaction to yield tetrasubstituted cyclohexenecarbaldehydes [140] The four stereogenic centers aregenerated in three consecutive CndashC bond formations thatis MichaelMichaelaldol condensation with high diastereo-and complete enantiocontrolThe synthesis of polyfunctionalcyclohexene building blocks involving proline catalytic stepsis reported in this domino reaction

Though this segment of our review is dedicated to prolineas an important class of organocatalysts it would also be agood place to acknowledge the research contributions fromprofessor Ahrendt et al to the field of organocatalysis [96 99100 103 127 131 141ndash150]

Heterogenized Proline An explosion of research articles inthe area of homogeneous organocatalysis occurredwithin thelast decade or so In addition to the initial proline catalyzedreactions the word ldquoorganocatalysisrdquo covers nowadays manyotherwell-knownorganocatalysts and organic reactions Pro-line immobilized onto some sort of inorganic support pavesthe way towards heterogenization of other organocatalysts[151ndash153] A simple and efficient synthesis of polystyrene-supported proline and prolinamide is reported Polystyrene-supported proline catalyzes the asymmetric aldol reactionbetween cyclohexanone and substituted benzaldehydes inwater High yields diastereoselectivities and ee values havebeen observedThe versatility of this resinwas also confirmedby selenenylation of aldehydes Both proline and prolinamideresins gave high yields Recycling studies showed that theproline resin performs as better heterogeneous organocat-alyst as compared to the prolinamide resin [153] An aldolreaction catalyzed by proline functionalized silica gel wasinvestigated in continuous flow microreactors by reaction-progress kinetic analysis and nonlinear chromatography[154]

Though the research community advocates asymmetricsynthesis for industrial application organocatalysts havebeen seldom applied in industry due to insufficient efficiencyand the difficulties in catalyst separation and recycling[155ndash161] The concept of heterogenizing organocatalyst onsupports combines the advantages of both homogeneousorganocatalysis and heterogeneous recycling Though thismight seem simple and present opportunities in indus-trial chemical processes the research in heterogeneousorganocatalysis demands a multidisciplinary approach byidentifying catalytic activity upon bonding organocatalystcovalently to the support understanding noncovalent inter-action as structure-reactivity and conformation decidingfactor taking into consideration the characteristic propertiesof the supports confinement effects if any and so forthSome recent examples will be described on the applicationsof supported proline as organocatalysts for their preindus-trialization study The latter half of this review in generalirons out the detailed discussion on key trendswith examplesscope challenges and ldquogreenrdquo applications of heterogeneousorganocatalysts

72 Other Amino Acids Barbas and coworkers found theproteinogenic amino acid tryptophan (Figure 4) to be anexcellent organocatalyst for the Mannich reaction of hydrox-yacetone with a variety of imines performed in DMF leadingthe desired anti-amino alcohols in excellent diastereoselec-tivities (up to gt19 1) and enantioselectivities (90ndash98 ee)Similarly t-butyl protected threonine catalyzed the aldolreaction of hydroxyacetone and various aldehydes in NMP togive the corresponding syn-aldol adducts in high yields andgood to excellent enantio- and diastereoselectivities [162]Zhao et al reported [163] the development of an aminoacid based small molecule capable of promoting asymmetricmonosilylation of meso-12-diols Furthermore the catalystcan be recycled with equal efficiency Three-componentreaction involving condensation of aldehyde 13-carbonyl

10 Journal of Catalysts

NH

OH

OH

O

O NHPh

O PhH

H

ON

NH

H

O OH

CO2BnCO2Bn

NO2

R1 R2

Scheme 5

NH

OH

O

H2N

Figure 4 L-Tryptophan

compound and (thio)urea is known as Biginelli reactionVarious organocatalysts such as tartaric acid oxalic acidcitric acid and lactic acid were found effective in producingBiginelli products [164ndash172]

Because of the ldquoprivilegedrdquo green nature of this fieldit has become an obligation for scientific community andacademic institutions to be mindful and teach this branchof catalysis to students and also keep it as a driving force inthe generation and dissemination of knowledge in pursuitof efficient synthetic methodologies and processes usingorganocatalysts The synthesis of new chiral building blocksor complex molecular structures involving organocatalyticstep(s) is being reported almost every day in scientificliterature As it is not possible here to discuss all the catalystsindividually in detail the author decides to present salientdevelopments in organocatalysis and allied research areas

Synthesis of prochiral cyclohexanones by amine cat-alyzed self-Diels-Alder reactions of 120572120573-unsaturated ketonesin water brought coupled the concept of green chemistry

with catalysis Useful asymmetric heterodomino reactionsfor the highly diastereoselective synthesis of symmetri-cal and nonsymmetrical synthons of benzoannelated cen-tropolyquinanes were reported [173 174]

In recent years trials are being made by using aminoacids especially L-proline to catalyze essential transforma-tions in the fine chemical and pharmaceutical industriesTheinterest in this field has thus increased spectacularly in the lastfew years However organocatalytic methods often requirecatalyst loadings as high as 30mol for the achievement ofhigh conversions in reasonable reaction times [175] Somecritics suggest that low turnover numbers might limit thepotential uses of organocatalysis for industrial applicationsProcess development and scale-up are being tested for severalorganocatalytic reactions confirming organocatalysis as avaluable tool for industrial scale solutions Scientists arereporting novel organocatalytic systems in various reputedinternational research journals and those catalysts exhibitvarious valuable functions derived from a variety of struc-tural ionicelectronic and chemical properties Broad varietyof efficient syntheses will contribute to an increasing numberof organocatalytic large scale reactions in the future Theorganocatalysts shall be used in various fields especially inasymmetric organic synthesis

73 Amine and Chiral Vicinal Diamines Proline and pyrro-lidine derivatives commonly known as Hayashi-Joslashrgensencatalysts in the form of ferrocenyl pyrrolidine are appliedas organocatalyst wherein the ferrocene moiety controls theconformational space and a simple alkyl group effectivelycovers a face of the derived enamine (Figure 5) [180]

Journal of Catalysts 11

R

RNR

REthanol rt

N

O

H

N

R R

+

10mol catalyst

R1

R1

R1R2

R3H2N

middotTfOH

Scheme 6

H NH

O

R

trans H N

O

H

RCis

Reactive conformation

Si

O

H

R

H

Ph

O

Ph

HO

SiCl3 Cl3

Scheme 7

Sulzer-Mosse and Alexakis reported chiral amines cat-alyzing asymmetric conjugate addition to nitroolefins andvinyl sulfones via enamine activation [181]

A bifunctional H-bond directing aminocatalytic systemis found to achieve high stereo- and regiocontrol overdienamine mediated hetero-Diels-Alder reaction [183]

Though amine catalysis is constructing a wide varietyof chiral scaffolds in asymmetric synthesis organocatalysiswith amines for nonasymmetric transformations is alsodeveloping very fast [184 185] The [2+2] cycloaddition ofenals with nitroalkenes is catalyzed by a chiral secondaryamine in the presence of an achiral thiourea for the enantio-and diastereoselective synthesis of highly functionalizedcyclobutanes Mechanistically two consecutiveMichael reac-tions proceed through an unprecedented combination ofdienamineiminium activation mode [186] The reactionengineering of dienamine catalysis for single-step synthesesof highly functionalized molecules such as natural productsor bioactive compounds is reviewed in literature [187]

Chin and coworkers have recently reported some pre-liminary theoretical and experimental studies for convertinga parent diamine into other chiral vicinal diamines Thesediamines can be handy as ligands for chiral catalysts or theycanmake chiral heterocyclic rings and betalactams [188ndash190]

There are some CndashC bonds forming reactions catalyzed bysuch diamine organocatalysts (Scheme 6) [191]

74 Amides Recently the synthesis of multifunctional or-ganocatalysts easily obtained by the condensation of (S)-proline with 2-aminopyridine 26-diaminopyridine or 2-aminoimidazole is reported These chiral prolinamides pro-moted the aldol condensation between cyclohexanone anddifferent aromatic aldehydes (up to 98ee) and also catalyzedDiels-Alder and Michael reactions [192 193]

Rationally designed pyrazole amides function as Michaeldonors in urea catalyzed asymmetric Michael reactions withexcellent chemical and optical yields [194]

A structure-activity relationship with regard to for-mamides as organocatalysts is exploredThis study highlightsthat the cis-conformation of secondary formamides is thereactive conformation in the allylation of aldehydes withallyltrichlorosilane (Scheme 7) [195]

75 Imidazolidinones A certain class of imidazolidinonecompounds (also called MacMillan imidazolidinone organ-ocatalysts) function as catalysts for many asymmetric organictransformations such as asymmetric Diels-Alder reactions

12 Journal of Catalysts

O

N

O

H

O

Up to 97 ee

OHH

N

NO

H20 mol catalyst

CHCl3 minus30∘C

C2H5O OC2H5

R1

R1

R2

R2

+

middotCF3CO2H

Scheme 8 Ouellet et al [202]

R

R

N

One favoured conformer

High enantioselectivity

R = alkyl

Fe

Figure 5

The original such compound was derived from the chi-ral biomolecule phenylalanine [196 197] The first highlyenantioselective organocatalytic Diels-Alder reaction usinga chiral organocatalyst was reported in MacMillanrsquos pio-neering work where the activated iminium ion formedthrough condensation of the imidazolidinone and an 120572120573-unsaturated aldehyde reacted with various dienes to give[4+2] cycloadducts in excellent yields and enantioselectivi-ties Ahrendt et al reportedmany other asymmetric reactionssuch as the 13-dipolar cycloadditions Friedel-Crafts alky-lations 120572-chlorinations 120572-fluorinations and intramolecularMichael reactions usingMacMillanrsquos organocatalysts [96 150198ndash201]

Ouellet et al also reported the combination of imida-zolidinone organocatalyst and Hantzsch ester to facilitatethe first enantioselective organocatalytic hydride reductionof 120572120573-unsaturated aldehydes (Scheme 8) [202 203] Thisimitated naturersquos stereoselective enzymatic transfer hydro-genation with NADH cofactor

Noncovalent interaction is a structure-reactivity andconformation deciding factor which requires immediateattention for understanding organocatalysis [204] Of specialinterest would be the identifying and understanding of othernoncovalent interactions such as charge transfer [205] pndashp stacking immobilization [206] and adsorption or entrap-ment of organocatalysts in nanomaterials [207]

Homogeneous and HeterogenizedMacMillanrsquos OrganocatalystAn asymmetric Diels-Alder reaction was catalyzed with highefficiency and recyclability by a soluble ldquoself-supportedrdquochiral organosilica polymer with embedded imidazolidinonecatalytic moieties [208]

76 Chiral Phosphoric Acids BINOL derived phosphoricacids catalyze nucleophilic addition reactions to imine sub-strates A direct Pictet-Spengler reaction was reported usinga geminally disubstituted tryptamine organocatalyst to formisoquinolines in excellent yield and enantiomeric excess[209] Phosphoric acid catalyzing the reduction of an iminewith a Hantzsch ester in good enantiomeric excess was firstlyreported by Rueping et al Hoffmann et al reported animprovement to this methodology [210 211]

Storer research group reported a one-pot reductive ami-nation of a range of methyl ketones and aryl amines [212]Reductive amination of 2-butanone over silylated phosphoricacid MacMillan TiPSY catalyst was obtained with goodenantiomeric excess

Zhou and List published on the use of chiral Broslashnstedacid (R)-TRIP for highly enantioselective synthesis of phar-maceutically relevant 3-substituted cyclohexylamines from26-diketones wherein the achiral amine substrate acceleratesthe cascade reaction before getting incorporated into the finalproduct (Scheme 9) [213]

Rowland et al reported VAPOL derived phosphoric acidcatalyzed addition of sulfonamides to BOC protected arylimines and protected aminals in excellent enantioselectivities[214]

The (R)-TRIP catalyzed the aza-Diels-Alder reaction ofaldimines with Danishefskyrsquos diene to yield piperidinonederivatives with high enantioselectivity Addition of aceticacid was found to improve both reactivity and enantiose-lectivity [215] Six chemical bonds five stereogenic centersand three cycles were formed in one-pot four-componentUgitype reaction catalyzed by a chiral BINOLderived phosphoricacid [216] BINAP is one of the earliy commercially appliedligands in industrial catalysis [217] Amicroporous recyclableheterogeneous catalyst offering excellent enantioselectivitywas made from a 111015840-binaphthalene-221015840-diol (binol) derivedphosphoric acid chloride and was found as active as thecorresponding homogeneous catalyst [218]

Journal of Catalysts 13

O

O

Ph

OEt HH

Ph

HN

OEt

i-Pr

i-Pr

i-Pri-Pr

i-Pr

i-Pr

O

OP O

OH

EtO2C CO2Et

CyclohexaneMS 5 A 50∘C

NH2

(R)-TRIP (10mol)

82 dr = 24 1 er = 98 21 22

Scheme 9 Zhou and List [213]

NO

N NHH N

HO

S

N

H R

BocO-PrTBS-O

Pr-O

HN

Boc

5mol catalyst+

t-Bu

t-Bu t-Bu

(2) TFA 2min(1) Toluene minus30∘C 48hr

86ndash98 ee

Scheme 10

HO OH

O O

Figure 6

77 Chiral Diols Huang et al reported on use of TADDOLs(Figure 6) as Broslashnsted acid organocatalysts in highly stereos-elective hetero-Diels-Alder reactions [219]

The 120572-amination of carbonyl compounds has also beenaccomplished by using the 1-naphthyl TADDOL derivative asa Broslashnsted acid organocatalyst [220] McDougal and Schausreported asymmetric Morita-Baylis-Hillman reaction that

is the addition of cyclohexenone to different aldehydescatalyzed by octahydro-BINOL derived Broslashnsted acid [221]

78 JacobsenThioureas ProfessorsVachal and Jacobsen iden-tified chiral thioureas (Figure 7) as versatile and effectiveorganocatalysts 1mol of the thiourea was reported to havecatalytic activity in the hydrocyanation (Strecker reaction) ofboth aldimines and ketoimines with very high enantioselec-tivities [222]

Imine hydrophosphonylation particularly effective withelectron-withdrawing ester substituents on the phosphatetook place in the presence of 10mol of the catalyst [223]Mannich reactions of BOC protected imines have also beenreported (Scheme 10) [224] with excellent yields and enan-tioselectivities and show heterocyclic substrate tolerance

A variant of thiourea organocatalyst was found to catalyzethe cyanosilylation of ketones and aldehydes in high yieldsand enantiomeric excesses [225] Thiourea organocatalystwas put to use in the acyl-Pictet-Spengler reaction to formtetrahydro-120573-carbolines [226] The acyl-Mannich reactionproviding a route to enantioenriched heterocycles from

14 Journal of Catalysts

N N N

H H NO H

HO

O

O

O

t-Bu

t-Bu

t-Bu

Figure 7

aromatic starting materials and trichloroethyl chloroformate(TrocCl) is also catalyzed by the thiourea organocatalyst[227] Bifunctional thiourea-base catalyzed double-Michaeladdition of benzofuran-2-ones to dienones is reported forthe synthesis of optically enriched spirocyclic benzofuran-2-ones [228] In another interesting example benzoylthiourea-pyrrolidine catalyst was synthesized and used in the asym-metric Michael addition of ketones to nitroalkenes [229]

Primary amine-thioureas were improvised to catalyzedifficult Michael reactions synthesizing (S)-baclofen (R)-baclofen and (S)-phenibut [230]

79 Cinchona Alkaloids The cinchona alkaloids catalyzemany useful processes with high enantioselectivities Asym-metric phase transfer catalysis (PTC) presents a ldquogreenrdquoalternative to homogeneous synthetic organic chemistrymethodologies Cinchona alkaloids are synthetically mod-ified for their usage in asymmetric PTC O-Alkyl N-arylmethyl derivatives of cinchona alkaloid led highly enantiose-lective alkylation of glycine imines to generate 120572-amino acidderivatives And for the same reaction dimeric cinchonaalkaloid obtained 97ndash99 enantiomeric excess [231 232]Cinchona alkaloids deprotonate substrates with relativelyacidic protons forming a contact ion pair between the result-ing anion and protonated amineThis interaction generates achiral pool around the anion and facilitates enantioselectivereactions with electrophiles The control over the formationof quaternary asymmetric centers is essential to obtain highenantiomeric excesses The 120572-functionalization of ketones(Scheme 11) by the addition of TMSCN to the correspondingcyanohydrin in excellent yield and enantiomeric excess iscatalyzed by the (DHQD)

2AQN catalyst [233]

Increasingly remote stereocenters are being targeted inasymmetric aminocatalysis Organocatalytic allylic amina-tion presents an alternative to the conventional palladiumcatalyzed methodology Amination at the remote 120574-positionusing (DHQ)

2PYR forms highly functionalized amine com-

pounds [234]Bella and Joslashrgensenrsquos reported the first enantioselective

conjugate addition of 120573-diketones to both aromatic andaliphatic alkynones using (DHQ)

2PHAL catalyst [235] Cin-

chona based primary amine catalysis is found to offer high

efficiency and reliability in the asymmetric functionalizationof carbonyl compounds [236 237] Organocatalysts derivedfrom cinchona alkaloids function as Lewis base catalyst inthe cyclizations of allenoates with electron deficient olefinsand imines and emerged as important synthetic tool inthe preparation of biologically active and pharmaceuticallyinteresting cyclic compounds including natural products[238] Recently cinchona thioureas have been reported forthe first time as catalysts in the area of asymmetric oxi-dations [239] Cinchona and cinchonidine derived catalystsperform asymmetric direct aldol reaction of pyruvic aldehydedimethyl acetal with isatin derivatives [240] Likewise thereare various other examples reported where cinchona or itsvariants are used as organocatalysts for syntheses of variousbiologically important molecules [241ndash246]

710 Maruoka Phase Transfer Catalysts The chiral catalystforms a host-guest complex with the substrate and shuttlesbetween the standard organic solvent and a second phaseexample catalytic enantioselective enolate alkylation [72]As we know chiral quaternary ammonium catalysts can beuseful in asymmetric synthesis Kitamura et al reported C2-symmetric ammonium salts catalyzing monoalkylation ofglycine derived Schiff bases with alkyl halides to synthesize120572-alkyl-120572-amino acids under remarkably low catalyst loadings[247ndash249]

Utilizing the solubility of aqueous quaternary ammoniumsalts into organic solvents professor Maruoka developedspirotype chiral ammonium salt with two binaphthyl ringsas a novel chiral phase transfer catalyst Figure 8 depicts theorganocatalyst for direct asymmetric aldol reaction of 120573-hydroxy-120572-amino acid derivative

711 Oxazaborolidines Chiral oxazaborolidines (known asCBS oxazaborolidines after Corey Bakshi and Shibata)catalyze the reduction of prochiral ketones imines andoximes to produce chiral alcohols amines and amino alco-hols respectively in high yields and excellent enantiomericexcesses The chiral Lewis acid generated from o-tolyl-CBS-oxazaborolidine after protonation with trifluoromethanesul-fonimide is very useful in the enantioselective Diels-Alderreaction (Scheme 12) [250ndash256]

Journal of Catalysts 15

O NC OTMSN

OH

N

N

OH

N

OO

2 to 20mol catalyst

TMSCN CHCl3

OC2H5

OC2H5

OC2H5

OC2H5

H3CO

C6H5C6H5

OCH3

Scheme 11 Tian et al [233]

OO

O

OO

II

CH3CH3

CH3

H3C

H3C TIPSOTIPSO

H

H

H

PhPh

NB

minus

+

+

(CF3SO2)2N

20mol catalyst

16hoursDichloromethane minus78∘C

Scheme 12 See [250ndash256]

712 Shi Epoxidation Catalyst Tu et al reported a fructosederived ketone in efficient asymmetric epoxidation of trans-olefins (Scheme 13) [257] Epoxidation catalyst is able toepoxidize trans-alkenes and certain cis-alkenes with good toexcellent yields and selectivities [258 259] Marigo et alrsquosgroup reported an asymmetric organocatalytic epoxidationof 120572 120573-unsaturated aldehydes with environmentally friendlyoxidant hydrogen peroxide [260]

713 N-Heterocyclic Carbene (NHC) as Organocatalysts

7131 Rovis Catalyst The conjugate addition of an aldehydeto an 120572120573-unsaturated compound (Stetter reaction) is apractical methodology for the construction of 14-dicarbonylcompounds bearing quaternary stereocenters Triazoliumsalt in the presence of a base functions as an N-heterocycliccarbene organocatalyst (Figure 9) in highly enantioselectiveintramolecular Stetter reactions [261 262]

7132 Bode Catalyst Bodersquos studies on NHCs (Figure 10)mainly involve catalytic generation of reactive speciessuch as enolates homoenolates and activated carboxylates

N-Mesityl substituent on an imidazolium or triazoliumNHCprecursor generates highly enantioselective annulations fromsimple starting materials under mild reaction conditions[263 264] In an interesting example the catalysts facilitatehighly enantioselective cyclopentene forming annulations ofsimple enals and activated enones [265] Redox esterificationsand amidations of 120572-functionalized aldehydes using achiralcatalyst are also reported [266] Uniting unique activationmodes of N-heterocyclic carbene (NHC) catalysts with theconcept of domino reactions a new fast-growing field cameinto the spotlight in last couple of years or so [267ndash269]

Domino Michaelaldol reaction between 2-mercapto-quinoline-3-carbaldehydes and enals was catalyzed by di-phenylprolinol silyl ether producing 2H-thiopyrano[23-b]-quinolines in excellent yields and enantioselectivities [270]Zhao et al reported studies on ldquocooperative NHC andrutheniun redox catalysisrdquo in the oxidative esterificationof aldehydes [271] Blanc et al reported NHC mediatedorganocatalytic one-pot allylstannation to generate syn-diols[272] With enals as starting aldehydes elegant cascadeprocesses have been developed using oxidative carbene catal-ysis [273ndash276] Over the last few years there are examplesreported in literature where various organocatalysts rally

16 Journal of Catalysts

O

Oxone

OO

O

O

OO

R1 R1

R3

R3

R2 R2H2OCH3CN

Scheme 13

F3C

N+

F3C

Brminus

CF3

CF3

Figure 8 See [176]

N

O

N

N

F

F

F

F

F

+BF4minus

Figure 9

domino reactions and attract their application in organicprocesses in industries [174 175 180 181 183]

Apart from the aforementioned organocatalysts thereare other organic systems which upon appropriate acti-vation function as catalysts in useful asymmetric synthe-ses [155ndash157] 12-Dicarbonyl compounds because of theiradjacent multiple reactive centers upon activation act asefficient pronucleophiles in asymmetric organocatalyzed

N

O

NN+

Clminus

Figure 10

sequential or domino transformations including CndashC or CndashN bond formation [277] Cyclopropenone catalyzed con-version of aldoximes and primary amides into nitriles ina one-pot mild reaction widens the scope of the utiliza-tion of cyclopropenones in organic synthesis [278] Thefirst asymmetric organocatalytic synthesis by phosphinecatalyzed [3+2] cycloaddition of allenoates onto fullereneis reported to yield enantiomerically pure carbocyclicfullerene derivatives under mild conditions [279] A new[3+2] cycloadditioncycloreversion strategy for organocat-alytic and thermally allowed carbonyl-olefin metathesis isreported [280] Recently a strong evidence for halogenbond based organocatalysis is reported for the reactionof 1-chloroisochroman with ketene silyl acetals [281] Acidcatalyzed asymmetric acetalizations of aldehydes are alsodescribed [282] beta-Isocupreidine catalyzed the enantios-elective Morita-Baylis-Hillman reaction of maleimides withisatin derivatives to form 3-substituted 3-hydroxyoxindolederivatives [283 284]

Recent advances in asymmetric catalysis resulted in uti-lizing the less discussed electrophilic properties of iminiumtype intermediates in complex annulations of indoles [285286] and also pyridines [287 288] Shibatomi and Narayamadiscussed the catalytic enantioselective 120572-chlorination of car-bonyl compounds and stereospecific substitution reactions ofthe resulting optically active alkyl chlorides [289]

Though there is no relation between the developmentof two different fields of organocatalysis and gold catalysis

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

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[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

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[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

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Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

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Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

4 Journal of Catalysts

Table 1 List of some of the industrially applied reactions and catalysts

Reaction Catalyst Inventor (Year)Sulphuric acid (leadmdashchamber process) NO

119909Clement Desormes (1806)

Chlorine production by HCl oxidation CuSO4 Deacon (1867)Nitric acid by NH3 oxidation Pt Rh nets Ostwald (1906)Fat hardening Ni Normann (1907)

Ammonia synthesis (H2 + N2) Fe Mittach Haber Bosch (1908)Production 1913 BASF

Hydrogenation of coal to hydrocarbons Fe Mo Sn Bergius (1913) Pier (1927)Methanol synthesis from CoH2 ZnoCr2O3 Mittach (1923)Hydrocarbons from COH2 (motor fuels) Fe Co Ni Fischer Tropsch (1925)Alkylation of olefins to gasoline AlCl3 Pines (1932)Cracking of hydrocarbons Al2O3SiO2 Houdry (1937)Cracking in a fluidized bed Aluminosilicates Lewis Gilliland (1939)Ethylene polymerization at low pressure Ti compounds Ziegler Natta (1954)Hydrogenation isomerization hydroformylation Rh- Ru complexes Wilkinson (1964)

Methanol carbonylation to acetic acidCoiodide BASF (1960)Rhiodide Monsanto Co (1966)Iridium BP Chemicals Ltd (2000)

Asymmetric hydrogenation Rhchiral phosphine Knowles (1974)Three-way catalyst Pt Rhmonolith General Motors (1974)Methanol conversion to hydrocarbons Zeolites Mobil Chemical Co (1975)Alpha-olefins from ethylene Nichelate phosphine Shell company (1977)Sharpless (epi) oxidation TIROOHTartarate May Baker Upjohn ARCO (1981)Selective oxidations with H2O2 TS-1 (titanium silicate) Enichem (1983)Hydroformylation Rhphosphine Rhone-Poulene-Ruhrchemie (1984)Polymerization of olefins ZirconoceneMAO Sinn Kaminsky (1985)Selective catalytic reduction (SCR) V W Ti oxidesmonolith 1986

Table 2 Differences between homogeneous catalysts and heteroge-neous catalysts

Homogeneous catalysts Heterogeneous catalystsSame phase as reaction medium Solid phaseDifficult separation Easily separableNo recyclability Recyclability and regenerationOften high rates of reaction Low rates of reactionNo diffusion control Diffusion controlRobust to poisoning Poisoning deactivationHigh selectivity Low selectivityShort life Long catalytic lifeMild conditions Energy-consuming processWell understood mechanism Poor mechanistic understanding

neutralized easily separated from organic materials anddisposed of This contributes to the huge quantity of aqueoussalt waste generated by industry Organometallic catalysts arecurrently widely used in industry but the search for improvedefficiencies enantioselectivities or recycling is still a matterof intense researches [29ndash33] It is true that homogeneouslycatalyzed processes such as hydroformylation carbonylationoxidation hydrogenation metathesis and hydrocyanationcontribute with millions of tons to the bulk chemicals but

on the other hand the progress of homogeneous catalysisis also going on with fine chemicals [25 33] In spirit ofthat the beginning of this century saw the renaissance oforganocatalysis presenting an environmental advantage overmetal based catalysts for stereoselective or asymmetric syn-thetic methodologiesThe absence of metal in organocatalystbrings an undeniable advantage considering the principles ofldquogreen chemistryrdquo and the economic point of view (Tables 3and 4)

Understanding catalytic systems involve study of struc-ture state and composition of catalysts and the phase inwhich they perform And for this one needs to understandchemistry of molecules and materials useful as catalysts andor catalyst carriers

4 Materials for Catalysis

The diversity of research field connected to the chemistry ofmaterials is significant for their applications in many areasincluding adsorption catalysis electrochemistry and surfacescience Nanoparticles [34] metal oxide and mixed metaloxides [35ndash38] prepared by simple methods are useful cata-lysts Research involving metal-organic frameworks [39 40]mesoporous silica [41ndash43] microporous or open-frameworkinorganic [44ndash46] andor mesopore modified [47] materials

Journal of Catalysts 5

Table 3 Comparison among organometallic catalysts enzyme catalysts and organocatalysts

Organometallic catalyst Enzyme catalyst Organocatalyst

Wide substrate scope high catalyticactivity involving tedious processpotential heavy metal pollution

Limited substrate scope highselectivity and catalytic activity

usually single enantiomer

Robust inexpensive readily available nontoxic inert towardmoisture and oxygen method especially attractive for the

preparation of compound that do not tolerate metal contamination(pharmaceutical products)

Table 4 Advantages and disadvantages of organocatalysts

Advantages DisadvantagesEasy preparation or availability High catalyst loadingEasy handling inert towards moisture(water) and air (oxygen) Relatively premature field

Easy scale-upNo metal contaminationEasy screeningUseful in complex (steric) reactions

has steadily increased following the widespread utility ofaluminosilicate zeolites [48ndash51] titanosilicates [52 53] andaluminium phosphates [54 55]

In industries research endeavours are mainly devotedtowards the study and development of zeolites or zeoliticmaterials with several attractive features such as cat-alytic active site(s) large surface area zeolitic pore wallsand pore size control The synthesis and characteriza-tion of the crystalline aluminosilicate materials with tun-able meso-microporosity and their strong acidity havepotentially important technological implications for shape-selective catalytic reactions ion exchange and adsorption oforganic compounds [56ndash58]Thepore diameters can be finelychosen tuned and utilized for exhibiting shape-selectivecatalysis depending on the molecular shapesize of organicreactant and product The widespread interest has beendeveloped in the zeolitic science towards the developmentand discovery of zeolites with desired characteristics sinceconventional zeolites lack fine tuning of their properties toacidbase and redox or bifunctional or multifunctional prop-erties Organic functionalization adds new catalytic functionsto zeolites [59]

Zeolites are microporous crystalline aluminosilicateswith unique properties used for many processes Zeolitespossess acid sites that are associated with the tetrahedralaluminium atoms in their framework and therefore theamount of acidity depends on the aluminium content ofthe zeolite Zeolite acid catalysts have wide application inindustrial processesThe introduction of Y-zeolites to replaceamorphous silica-alumina in fluidized catalytic cracking(FCC) and in hydrocracking processes in the early 1960rsquos wasa breakthrough application in acid catalysis With the everincreasing research efforts in this area leading to discoveriesof new structures and modification schemes by academicand industrial laboratories the potential of solid acids hasevolved tremendously However with the exception of theZSM-5 Mordenite and to some extent Beta zeolite very few

of these structures have been applied in industrial processesto any significant extent Yet one can account for relativelyfew applications to the huge number of new materialsintroduced Notable examples are the reported uses of SAPOsin lube dewaxing and in natural gas to olefin technologiesand MCM-22 in aromatics alkylation The zeolite structureswith large-porebimodal porosity and tunable acidity canbe a remarkable benefit for catalytic processes in industriesWithin industrial catalysis there are constant innovation andchanging approaches to provision of selective economicallyviable and environmentally benign processes

Recently enormous growth in the chemical diversity ofinorganic materials with transition-metal incorporation innew compositional domains has also been explored dueto their potential application in adsorption and catalysisInorganic polymers transition metal phosphates and metal-organic frameworks [39 40] with novel catalytic electronicmagnetic and unique structural properties are particularlypromising candidates [60ndash64] The mesoporous structurewith strong acidity can be a remarkable benefit for catalyticreactions involving large organic molecules in which diffu-sion constraints andor adsorption of reactantmolecules ontothe strong acid sites are the main concern A lot has beenreported about the pathways to developmesostructured silica[65] In terms of surface functionalization the performanceof mesoporous silica has been polished by several methodssuch as metal incorporation [66] metal deposition [67]grafting by organic functional groups [68] and immobiliz-ing metal complex [69] New approaches to synthesis andcharacterization of bimodal that is micro-mesoporous andor meso-macroporous materials might assist us in under-standing the phenomena of diffusion confinement effectsselectivity and so forth [47]

5 Organocatalysis A NovelSynthetic Philosophy

The term ldquoorganocatalystrdquo is a concatenation of the wordsldquoorganicrdquo and ldquocatalystrdquo The definition corresponds to a lowmolecular weight organicmolecule which in substoichiomet-ric amounts catalyzes a chemical reactionThe organocatalystcould be achiral or chiral and could be composed of CH N S and P Organocatalysis has several advantages notonly because of its synthetic range but also for the economicreasons The absence of metal in organocatalyst brings anundeniable advantage considering both the principles ofldquogreen chemistryrdquo and the economic point of view (Figure 3)

Nowadays organocatalysis is one of the hot researchtopics in advanced organic chemistry It is a novel syn-thetic philosophy and mostly an alternative to the prevalent

6 Journal of Catalysts

N

H

L-ProlineN

N

DMAP

OH

Nobin

N

NO

H

MacMillanrsquos catalyst

O

N

HO N

Quinine

CO2H

NH2

∙ ∙

Figure 3 Few famous examples of organocatalysts L-proline DMAP quinine and MacMillanrsquos catalyst

transition metal catalysis Organocatalysts are often basedon nontoxic organic compounds originating from biologicalmaterials Organocatalysts can be Lewis bases Lewis acidsBroslashnsted bases and Broslashnsted acids Most of the organocatal-ysis reported so far are explained by Lewis base mechanismThe Lewis base mechanism can be simplified as follows

Step I Lewis base for example cinchona alkaloidinitiates catalysis via a nucleophilic addition to ordeprotonation of the substrateStep II the chiral intermediate undergoes reactionStep III separation of product(s) from the catalystoccursStep IV regeneration of the catalyst and its availabilityfor a new catalytic cycle occurs

There are many organocatalytic reactions that need a secondmechanism to explain the catalytic cycle involved This iscalled bifunctional organocatalysis in which the organocata-lyst possesses not only a Lewis base (nitrogen or phosphorusatom) but also a Broslashnsted acidic site There is a lot to be donein redox catalysis and in exploitation of the synergetic effect ofdifferent catalytic active sites within one organic compoundor material

Some advantages of organocatalysts include the following

(i) Reactions performed by organocatalysts have poten-tial application in large scale production in industries

(ii) Scope organic reactions occur which are not inpractice and not possible by other forms of catalystsfor example asymmetric synthetic processes

(iii) PriceAvailability Low cost alkaloids natural aminoacids L-proline tartaric acid and so forth are easilyavailable and are economically attractive

(iv) Recycling issues immobilization of the catalyst is thesimplest way to recover it

(v) Some of the examples include bioderived andbiodegradable organocatalysts

(vi) Organocatalysts work at mild reaction conditions(vii) Sometimes the final products of reactions contain

high levels of metal contamination derived from cat-alyst degradation phenomena which pose a seriousdrawback if the metal is toxic for pharmaceutical andfood industries Absence of transition-metal bringsorganocatalysis at the heart of greening chemistry

Organocatalysis can be categorized into our different typesas follows

Type-I activation of the reaction based on the nucle-ophilicelectrophilic properties of the catalyst is done(Scheme 1)

Type-II organic molecules form reactive intermedi-ates The chiral catalyst is consumed in the reactionand requires regeneration in parallel catalytic cycle asit is reported in Scheme 2

Type-III phase transfer reactions occur The chiralcatalyst forms a host-guest complexwith the substrateand shuttles between the standard organic solvent anda second phase

Journal of Catalysts 7

O

O

O

O

OOH

100

N

H

3mol L-proline

DMF 20∘C 20h

CO2H

Scheme 1 Hajos and Parrish [70]

O

O

OOO

O

O

30mol catalyst

30 H2O2 (3 equivalent)

CH3CNndashK2CO3

R1R3

R2

R1R3

R2

Scheme 2 Shu and Shi [71]

Catalytic enantioselective enolate alkylation(Scheme 3) occurs

Type-IV molecular-cavity-accelerated asymmetrictransformations occur in which the catalyst mayselect from competing substrates depending on sizeand structure criteria (Scheme 4)

6 Discovery and the History ofOrganocatalysis

Liebigrsquos synthesis of oxamide from dicyan and water is thefirst organocatalytic reaction reported [74] Acetaldehydewasfurther identified to behave as the then-named ldquofermentrdquonow called as enzyme Dakin in 1909 demonstrated that ina Knoevenagel type condensation between aldehydes andcarboxylic acids or esters with active methylene groups theamine catalysts could be mediated by amino acids [75]Langenbeck is remembered for developing enamine typereactions and the application of simple amino acids andsmall oligopeptides as catalysts [76ndash78] Natural products inparticular strychnine brucine and cinchona alkaloids andamino acids (including short oligopeptides) were amongthe first organic catalysts tested [79 80] Though the fieldof small-molecule catalysts seems very simple there are

evidences that prove their pivotal role in synthesis of buildingblocks for life L-Alanine andL-isovaline capable of catalyzingcertain CndashC bond formation reactions had been found onmeteorites [81]

An asymmetric transformation with an organic moleculewas published in 1912 by Bredig and Fiske [82] Pracejusapplied cinchona alkaloids in the asymmetric conversionof ketenes to (S)-methyl hydratropate [83 84] An initialresearch byYamadaampOtaniwas important too [85]The sev-enties brought anothermilestone Hajos and Parrish reporteda L-proline catalyzed Robinson annulation in excellent enan-tioselectivities [70 86 87] Eder et al reported organocat-alytic aldol reactions in good enantioselectivities [88] Tosummarize in 1970s Hajos and Parrish and independentlyEder Sauer and Wiechert published a series of papers andpatents involving such organocatalytic transformations Theasymmetric synthesis of enediones useful building blocksin natural product total syntheses was achieved (S)-Prolineinduced the formation of (S)-enediones

Two mechanisms [89] were proposed (1) involving theformation of a carbinolamine intermediate followed by thedisplacement of the proline moiety by nucleophilic attackof the enol from the side chain ketone (2) involving anenaminium intermediate acting as a nucleophile in the CndashCbond formation with concomitant NHsdot sdot sdotO hydrogen trans-fer Wynberg firstly published various 12 and 14 additionscatalyzed by cinchona bifunctional organocatalysis [90ndash92]

8 Journal of Catalysts

N

O

Ph

Ph

Ph

Ph

N

O

OO

O

81 96 eeO

O

O

O

H N

Chiral quaternary ammonium catalyst10mol catalyst

CH2Cl2BrH2C

Ot-Bu

Ot-Buminus78

∘C 24h

+

Brminus

CsOHmiddotH2O

Scheme 3 Corey et al [72]

O

BOCHN BOCHN

OO OH

Nu

OH

(2) Nu

(1) Polymer

HO

N

HN

HO

O

O

OH

NO2

NO2

+

Scheme 4 Sellergren et al [73]

All these research endeavours were not carefully looked intotill List et al reported in 2000 proline catalyzed aldol reactionin good enantiomeric excesses [93 94]

Asymmetric catalysis constitutes one of the most impor-tant subjects in synthetic organic chemistry Asymmetricsynthesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the application of such methodologies inchemical industry is rather limited due to the high cost ofchiral ligands and noble metals used in such transformationsMoreover the pharmaceutical entities and food industryproducts do not tolerate a contamination of even traces ofany such metals for that matter Synthesis of chiral drugshas a major financial impact in pharmaceutical industrieson a global scale Different enantiomers or diastereomers ofa molecule often have different biological activity Most ofthe drugs might be soon sold as single enantiomers in thecoming years There is a huge demand for organocatalystsleading to 100 yield 100 ee of the desired product Theneed from chemical industry especially pharmaceutical forreliable asymmetric transformations of molecular skeletonsis higher than ever Therefore asymmetric organocatalysisis in a process of attaining maturity into a very powerful

practical and broadly applicable methodological approach inthe catalytic asymmetric synthesis

7 Some Examples and Developments inCatalyst Structural Variants

Following are the famous examples of organocatalysts

71 Proline and Derivatives The proline catalyzed Robinsonannulation was one of the earliest examples of an enantios-elective reaction using an organic catalyst [85] This aminoacid contains both a nucleophilic secondary amino groupand a carboxylic acid moiety functioning as a Broslashnstedacid The availability of proline in both enantiomeric formsbrings advantages over enzymatic methods Arguably thefirst example of proline catalyzed asymmetric aldol reactionis reported by Hajos and Parrish [70 86 87] The Wieland-Miescher ketone is a useful synthetic building block forwhich a classical asymmetric procedure using (S)-prolinewas published forty years ago [88] It is quite significant thatthe first efficient organocatalyzed asymmetric reactions weredescribed by Hajos amp Parrish [86 87] and by Eder et al [88]

Journal of Catalysts 9

both teams from pharmaceutical companies (Hoffmann-la-Roche and Schering) The asymmetric synthesis of theWieland-Miescher ketone is also based on proline andanother early application was one of the transformations inthe total synthesis of erythromycin by Woodward et al [95]Proline is recognized as a versatile organocatalyst of thesetimes (Scheme 5)

In fact the renewal of proline catalyzed transformationsin early 2000 by D W C MacMillan Carlos F Barbas IIIand Benjamin List saw the renaissance of the concept and itwas the starting point of the word ldquoorganocatalysisrdquo ProfessorAhrendt group reported the first enantioselective organocat-alytic Diels-Alder reaction [96] Proline was identified asan effective organocatalyst for asymmetric aldol reaction[97] The catalytic asymmetric 120572-alkylation of aldehydeswas reported by Vignola and List [98] This transformationhad been accomplished with the help of covalently attachedauxiliaries 120572-Methyl L-proline exhibits higher enantioselec-tivities and improved reaction rates when compared to L-proline In recent years proline especially L-proline hasbeen used to catalyze essential transformations used in thefine chemical and pharmaceutical industries such as thedirect asymmetric aldol reactions [99ndash107] Diels-Alder reac-tions Michael reactions [108ndash115] Mannich reaction [116ndash122] Multicomponent reactions [123 124] and 120572-amination[125] 120572-aminoxylation [126ndash128] 120572-oxyaldehyde dimer-ization [100] 120572-functionalization of carbonyl compounds[129] and 120572-alkylation of aldehydes [130] Organocat-alytic cyclopropanation reactions were typically performedusing catalyst-bound ylides However Kunz and MacMil-lan demonstrated that activation of olefin substrates usingcatalytic (S)-(minus)-indoline-2-carboxylic acid is a viable routefor the formation of highly enantioenriched cyclopropanes[131]

Prof K A Joslashrgensen has made an importantbreakthrough in asymmetric synthesis by developing (R)-and (S)-120572120572-bis[35-bis(trifluoromethyl)phenyl]-2-pyrroli-dinemethanol trimethylsilyl ether as excellent chiral organ-ocatalysts in the direct organocatalytic 120572-functionaliza-tion of aldehydes Diarylprolinol silyl ether reagents werefound to catalyze CndashC CndashN CndashO CndashS and CndashHal bondforming reactions [132ndash138] Cascade or domino reactionsswiftly construct complex biologically important compoundsand minimize waste and also the laboratory operations [139]Endersrsquo group developed proline derived organocatalyst fora chemo- diastereo- and enantioselective three-componentdomino reaction to yield tetrasubstituted cyclohexenecarbaldehydes [140] The four stereogenic centers aregenerated in three consecutive CndashC bond formations thatis MichaelMichaelaldol condensation with high diastereo-and complete enantiocontrolThe synthesis of polyfunctionalcyclohexene building blocks involving proline catalytic stepsis reported in this domino reaction

Though this segment of our review is dedicated to prolineas an important class of organocatalysts it would also be agood place to acknowledge the research contributions fromprofessor Ahrendt et al to the field of organocatalysis [96 99100 103 127 131 141ndash150]

Heterogenized Proline An explosion of research articles inthe area of homogeneous organocatalysis occurredwithin thelast decade or so In addition to the initial proline catalyzedreactions the word ldquoorganocatalysisrdquo covers nowadays manyotherwell-knownorganocatalysts and organic reactions Pro-line immobilized onto some sort of inorganic support pavesthe way towards heterogenization of other organocatalysts[151ndash153] A simple and efficient synthesis of polystyrene-supported proline and prolinamide is reported Polystyrene-supported proline catalyzes the asymmetric aldol reactionbetween cyclohexanone and substituted benzaldehydes inwater High yields diastereoselectivities and ee values havebeen observedThe versatility of this resinwas also confirmedby selenenylation of aldehydes Both proline and prolinamideresins gave high yields Recycling studies showed that theproline resin performs as better heterogeneous organocat-alyst as compared to the prolinamide resin [153] An aldolreaction catalyzed by proline functionalized silica gel wasinvestigated in continuous flow microreactors by reaction-progress kinetic analysis and nonlinear chromatography[154]

Though the research community advocates asymmetricsynthesis for industrial application organocatalysts havebeen seldom applied in industry due to insufficient efficiencyand the difficulties in catalyst separation and recycling[155ndash161] The concept of heterogenizing organocatalyst onsupports combines the advantages of both homogeneousorganocatalysis and heterogeneous recycling Though thismight seem simple and present opportunities in indus-trial chemical processes the research in heterogeneousorganocatalysis demands a multidisciplinary approach byidentifying catalytic activity upon bonding organocatalystcovalently to the support understanding noncovalent inter-action as structure-reactivity and conformation decidingfactor taking into consideration the characteristic propertiesof the supports confinement effects if any and so forthSome recent examples will be described on the applicationsof supported proline as organocatalysts for their preindus-trialization study The latter half of this review in generalirons out the detailed discussion on key trendswith examplesscope challenges and ldquogreenrdquo applications of heterogeneousorganocatalysts

72 Other Amino Acids Barbas and coworkers found theproteinogenic amino acid tryptophan (Figure 4) to be anexcellent organocatalyst for the Mannich reaction of hydrox-yacetone with a variety of imines performed in DMF leadingthe desired anti-amino alcohols in excellent diastereoselec-tivities (up to gt19 1) and enantioselectivities (90ndash98 ee)Similarly t-butyl protected threonine catalyzed the aldolreaction of hydroxyacetone and various aldehydes in NMP togive the corresponding syn-aldol adducts in high yields andgood to excellent enantio- and diastereoselectivities [162]Zhao et al reported [163] the development of an aminoacid based small molecule capable of promoting asymmetricmonosilylation of meso-12-diols Furthermore the catalystcan be recycled with equal efficiency Three-componentreaction involving condensation of aldehyde 13-carbonyl

10 Journal of Catalysts

NH

OH

OH

O

O NHPh

O PhH

H

ON

NH

H

O OH

CO2BnCO2Bn

NO2

R1 R2

Scheme 5

NH

OH

O

H2N

Figure 4 L-Tryptophan

compound and (thio)urea is known as Biginelli reactionVarious organocatalysts such as tartaric acid oxalic acidcitric acid and lactic acid were found effective in producingBiginelli products [164ndash172]

Because of the ldquoprivilegedrdquo green nature of this fieldit has become an obligation for scientific community andacademic institutions to be mindful and teach this branchof catalysis to students and also keep it as a driving force inthe generation and dissemination of knowledge in pursuitof efficient synthetic methodologies and processes usingorganocatalysts The synthesis of new chiral building blocksor complex molecular structures involving organocatalyticstep(s) is being reported almost every day in scientificliterature As it is not possible here to discuss all the catalystsindividually in detail the author decides to present salientdevelopments in organocatalysis and allied research areas

Synthesis of prochiral cyclohexanones by amine cat-alyzed self-Diels-Alder reactions of 120572120573-unsaturated ketonesin water brought coupled the concept of green chemistry

with catalysis Useful asymmetric heterodomino reactionsfor the highly diastereoselective synthesis of symmetri-cal and nonsymmetrical synthons of benzoannelated cen-tropolyquinanes were reported [173 174]

In recent years trials are being made by using aminoacids especially L-proline to catalyze essential transforma-tions in the fine chemical and pharmaceutical industriesTheinterest in this field has thus increased spectacularly in the lastfew years However organocatalytic methods often requirecatalyst loadings as high as 30mol for the achievement ofhigh conversions in reasonable reaction times [175] Somecritics suggest that low turnover numbers might limit thepotential uses of organocatalysis for industrial applicationsProcess development and scale-up are being tested for severalorganocatalytic reactions confirming organocatalysis as avaluable tool for industrial scale solutions Scientists arereporting novel organocatalytic systems in various reputedinternational research journals and those catalysts exhibitvarious valuable functions derived from a variety of struc-tural ionicelectronic and chemical properties Broad varietyof efficient syntheses will contribute to an increasing numberof organocatalytic large scale reactions in the future Theorganocatalysts shall be used in various fields especially inasymmetric organic synthesis

73 Amine and Chiral Vicinal Diamines Proline and pyrro-lidine derivatives commonly known as Hayashi-Joslashrgensencatalysts in the form of ferrocenyl pyrrolidine are appliedas organocatalyst wherein the ferrocene moiety controls theconformational space and a simple alkyl group effectivelycovers a face of the derived enamine (Figure 5) [180]

Journal of Catalysts 11

R

RNR

REthanol rt

N

O

H

N

R R

+

10mol catalyst

R1

R1

R1R2

R3H2N

middotTfOH

Scheme 6

H NH

O

R

trans H N

O

H

RCis

Reactive conformation

Si

O

H

R

H

Ph

O

Ph

HO

SiCl3 Cl3

Scheme 7

Sulzer-Mosse and Alexakis reported chiral amines cat-alyzing asymmetric conjugate addition to nitroolefins andvinyl sulfones via enamine activation [181]

A bifunctional H-bond directing aminocatalytic systemis found to achieve high stereo- and regiocontrol overdienamine mediated hetero-Diels-Alder reaction [183]

Though amine catalysis is constructing a wide varietyof chiral scaffolds in asymmetric synthesis organocatalysiswith amines for nonasymmetric transformations is alsodeveloping very fast [184 185] The [2+2] cycloaddition ofenals with nitroalkenes is catalyzed by a chiral secondaryamine in the presence of an achiral thiourea for the enantio-and diastereoselective synthesis of highly functionalizedcyclobutanes Mechanistically two consecutiveMichael reac-tions proceed through an unprecedented combination ofdienamineiminium activation mode [186] The reactionengineering of dienamine catalysis for single-step synthesesof highly functionalized molecules such as natural productsor bioactive compounds is reviewed in literature [187]

Chin and coworkers have recently reported some pre-liminary theoretical and experimental studies for convertinga parent diamine into other chiral vicinal diamines Thesediamines can be handy as ligands for chiral catalysts or theycanmake chiral heterocyclic rings and betalactams [188ndash190]

There are some CndashC bonds forming reactions catalyzed bysuch diamine organocatalysts (Scheme 6) [191]

74 Amides Recently the synthesis of multifunctional or-ganocatalysts easily obtained by the condensation of (S)-proline with 2-aminopyridine 26-diaminopyridine or 2-aminoimidazole is reported These chiral prolinamides pro-moted the aldol condensation between cyclohexanone anddifferent aromatic aldehydes (up to 98ee) and also catalyzedDiels-Alder and Michael reactions [192 193]

Rationally designed pyrazole amides function as Michaeldonors in urea catalyzed asymmetric Michael reactions withexcellent chemical and optical yields [194]

A structure-activity relationship with regard to for-mamides as organocatalysts is exploredThis study highlightsthat the cis-conformation of secondary formamides is thereactive conformation in the allylation of aldehydes withallyltrichlorosilane (Scheme 7) [195]

75 Imidazolidinones A certain class of imidazolidinonecompounds (also called MacMillan imidazolidinone organ-ocatalysts) function as catalysts for many asymmetric organictransformations such as asymmetric Diels-Alder reactions

12 Journal of Catalysts

O

N

O

H

O

Up to 97 ee

OHH

N

NO

H20 mol catalyst

CHCl3 minus30∘C

C2H5O OC2H5

R1

R1

R2

R2

+

middotCF3CO2H

Scheme 8 Ouellet et al [202]

R

R

N

One favoured conformer

High enantioselectivity

R = alkyl

Fe

Figure 5

The original such compound was derived from the chi-ral biomolecule phenylalanine [196 197] The first highlyenantioselective organocatalytic Diels-Alder reaction usinga chiral organocatalyst was reported in MacMillanrsquos pio-neering work where the activated iminium ion formedthrough condensation of the imidazolidinone and an 120572120573-unsaturated aldehyde reacted with various dienes to give[4+2] cycloadducts in excellent yields and enantioselectivi-ties Ahrendt et al reportedmany other asymmetric reactionssuch as the 13-dipolar cycloadditions Friedel-Crafts alky-lations 120572-chlorinations 120572-fluorinations and intramolecularMichael reactions usingMacMillanrsquos organocatalysts [96 150198ndash201]

Ouellet et al also reported the combination of imida-zolidinone organocatalyst and Hantzsch ester to facilitatethe first enantioselective organocatalytic hydride reductionof 120572120573-unsaturated aldehydes (Scheme 8) [202 203] Thisimitated naturersquos stereoselective enzymatic transfer hydro-genation with NADH cofactor

Noncovalent interaction is a structure-reactivity andconformation deciding factor which requires immediateattention for understanding organocatalysis [204] Of specialinterest would be the identifying and understanding of othernoncovalent interactions such as charge transfer [205] pndashp stacking immobilization [206] and adsorption or entrap-ment of organocatalysts in nanomaterials [207]

Homogeneous and HeterogenizedMacMillanrsquos OrganocatalystAn asymmetric Diels-Alder reaction was catalyzed with highefficiency and recyclability by a soluble ldquoself-supportedrdquochiral organosilica polymer with embedded imidazolidinonecatalytic moieties [208]

76 Chiral Phosphoric Acids BINOL derived phosphoricacids catalyze nucleophilic addition reactions to imine sub-strates A direct Pictet-Spengler reaction was reported usinga geminally disubstituted tryptamine organocatalyst to formisoquinolines in excellent yield and enantiomeric excess[209] Phosphoric acid catalyzing the reduction of an iminewith a Hantzsch ester in good enantiomeric excess was firstlyreported by Rueping et al Hoffmann et al reported animprovement to this methodology [210 211]

Storer research group reported a one-pot reductive ami-nation of a range of methyl ketones and aryl amines [212]Reductive amination of 2-butanone over silylated phosphoricacid MacMillan TiPSY catalyst was obtained with goodenantiomeric excess

Zhou and List published on the use of chiral Broslashnstedacid (R)-TRIP for highly enantioselective synthesis of phar-maceutically relevant 3-substituted cyclohexylamines from26-diketones wherein the achiral amine substrate acceleratesthe cascade reaction before getting incorporated into the finalproduct (Scheme 9) [213]

Rowland et al reported VAPOL derived phosphoric acidcatalyzed addition of sulfonamides to BOC protected arylimines and protected aminals in excellent enantioselectivities[214]

The (R)-TRIP catalyzed the aza-Diels-Alder reaction ofaldimines with Danishefskyrsquos diene to yield piperidinonederivatives with high enantioselectivity Addition of aceticacid was found to improve both reactivity and enantiose-lectivity [215] Six chemical bonds five stereogenic centersand three cycles were formed in one-pot four-componentUgitype reaction catalyzed by a chiral BINOLderived phosphoricacid [216] BINAP is one of the earliy commercially appliedligands in industrial catalysis [217] Amicroporous recyclableheterogeneous catalyst offering excellent enantioselectivitywas made from a 111015840-binaphthalene-221015840-diol (binol) derivedphosphoric acid chloride and was found as active as thecorresponding homogeneous catalyst [218]

Journal of Catalysts 13

O

O

Ph

OEt HH

Ph

HN

OEt

i-Pr

i-Pr

i-Pri-Pr

i-Pr

i-Pr

O

OP O

OH

EtO2C CO2Et

CyclohexaneMS 5 A 50∘C

NH2

(R)-TRIP (10mol)

82 dr = 24 1 er = 98 21 22

Scheme 9 Zhou and List [213]

NO

N NHH N

HO

S

N

H R

BocO-PrTBS-O

Pr-O

HN

Boc

5mol catalyst+

t-Bu

t-Bu t-Bu

(2) TFA 2min(1) Toluene minus30∘C 48hr

86ndash98 ee

Scheme 10

HO OH

O O

Figure 6

77 Chiral Diols Huang et al reported on use of TADDOLs(Figure 6) as Broslashnsted acid organocatalysts in highly stereos-elective hetero-Diels-Alder reactions [219]

The 120572-amination of carbonyl compounds has also beenaccomplished by using the 1-naphthyl TADDOL derivative asa Broslashnsted acid organocatalyst [220] McDougal and Schausreported asymmetric Morita-Baylis-Hillman reaction that

is the addition of cyclohexenone to different aldehydescatalyzed by octahydro-BINOL derived Broslashnsted acid [221]

78 JacobsenThioureas ProfessorsVachal and Jacobsen iden-tified chiral thioureas (Figure 7) as versatile and effectiveorganocatalysts 1mol of the thiourea was reported to havecatalytic activity in the hydrocyanation (Strecker reaction) ofboth aldimines and ketoimines with very high enantioselec-tivities [222]

Imine hydrophosphonylation particularly effective withelectron-withdrawing ester substituents on the phosphatetook place in the presence of 10mol of the catalyst [223]Mannich reactions of BOC protected imines have also beenreported (Scheme 10) [224] with excellent yields and enan-tioselectivities and show heterocyclic substrate tolerance

A variant of thiourea organocatalyst was found to catalyzethe cyanosilylation of ketones and aldehydes in high yieldsand enantiomeric excesses [225] Thiourea organocatalystwas put to use in the acyl-Pictet-Spengler reaction to formtetrahydro-120573-carbolines [226] The acyl-Mannich reactionproviding a route to enantioenriched heterocycles from

14 Journal of Catalysts

N N N

H H NO H

HO

O

O

O

t-Bu

t-Bu

t-Bu

Figure 7

aromatic starting materials and trichloroethyl chloroformate(TrocCl) is also catalyzed by the thiourea organocatalyst[227] Bifunctional thiourea-base catalyzed double-Michaeladdition of benzofuran-2-ones to dienones is reported forthe synthesis of optically enriched spirocyclic benzofuran-2-ones [228] In another interesting example benzoylthiourea-pyrrolidine catalyst was synthesized and used in the asym-metric Michael addition of ketones to nitroalkenes [229]

Primary amine-thioureas were improvised to catalyzedifficult Michael reactions synthesizing (S)-baclofen (R)-baclofen and (S)-phenibut [230]

79 Cinchona Alkaloids The cinchona alkaloids catalyzemany useful processes with high enantioselectivities Asym-metric phase transfer catalysis (PTC) presents a ldquogreenrdquoalternative to homogeneous synthetic organic chemistrymethodologies Cinchona alkaloids are synthetically mod-ified for their usage in asymmetric PTC O-Alkyl N-arylmethyl derivatives of cinchona alkaloid led highly enantiose-lective alkylation of glycine imines to generate 120572-amino acidderivatives And for the same reaction dimeric cinchonaalkaloid obtained 97ndash99 enantiomeric excess [231 232]Cinchona alkaloids deprotonate substrates with relativelyacidic protons forming a contact ion pair between the result-ing anion and protonated amineThis interaction generates achiral pool around the anion and facilitates enantioselectivereactions with electrophiles The control over the formationof quaternary asymmetric centers is essential to obtain highenantiomeric excesses The 120572-functionalization of ketones(Scheme 11) by the addition of TMSCN to the correspondingcyanohydrin in excellent yield and enantiomeric excess iscatalyzed by the (DHQD)

2AQN catalyst [233]

Increasingly remote stereocenters are being targeted inasymmetric aminocatalysis Organocatalytic allylic amina-tion presents an alternative to the conventional palladiumcatalyzed methodology Amination at the remote 120574-positionusing (DHQ)

2PYR forms highly functionalized amine com-

pounds [234]Bella and Joslashrgensenrsquos reported the first enantioselective

conjugate addition of 120573-diketones to both aromatic andaliphatic alkynones using (DHQ)

2PHAL catalyst [235] Cin-

chona based primary amine catalysis is found to offer high

efficiency and reliability in the asymmetric functionalizationof carbonyl compounds [236 237] Organocatalysts derivedfrom cinchona alkaloids function as Lewis base catalyst inthe cyclizations of allenoates with electron deficient olefinsand imines and emerged as important synthetic tool inthe preparation of biologically active and pharmaceuticallyinteresting cyclic compounds including natural products[238] Recently cinchona thioureas have been reported forthe first time as catalysts in the area of asymmetric oxi-dations [239] Cinchona and cinchonidine derived catalystsperform asymmetric direct aldol reaction of pyruvic aldehydedimethyl acetal with isatin derivatives [240] Likewise thereare various other examples reported where cinchona or itsvariants are used as organocatalysts for syntheses of variousbiologically important molecules [241ndash246]

710 Maruoka Phase Transfer Catalysts The chiral catalystforms a host-guest complex with the substrate and shuttlesbetween the standard organic solvent and a second phaseexample catalytic enantioselective enolate alkylation [72]As we know chiral quaternary ammonium catalysts can beuseful in asymmetric synthesis Kitamura et al reported C2-symmetric ammonium salts catalyzing monoalkylation ofglycine derived Schiff bases with alkyl halides to synthesize120572-alkyl-120572-amino acids under remarkably low catalyst loadings[247ndash249]

Utilizing the solubility of aqueous quaternary ammoniumsalts into organic solvents professor Maruoka developedspirotype chiral ammonium salt with two binaphthyl ringsas a novel chiral phase transfer catalyst Figure 8 depicts theorganocatalyst for direct asymmetric aldol reaction of 120573-hydroxy-120572-amino acid derivative

711 Oxazaborolidines Chiral oxazaborolidines (known asCBS oxazaborolidines after Corey Bakshi and Shibata)catalyze the reduction of prochiral ketones imines andoximes to produce chiral alcohols amines and amino alco-hols respectively in high yields and excellent enantiomericexcesses The chiral Lewis acid generated from o-tolyl-CBS-oxazaborolidine after protonation with trifluoromethanesul-fonimide is very useful in the enantioselective Diels-Alderreaction (Scheme 12) [250ndash256]

Journal of Catalysts 15

O NC OTMSN

OH

N

N

OH

N

OO

2 to 20mol catalyst

TMSCN CHCl3

OC2H5

OC2H5

OC2H5

OC2H5

H3CO

C6H5C6H5

OCH3

Scheme 11 Tian et al [233]

OO

O

OO

II

CH3CH3

CH3

H3C

H3C TIPSOTIPSO

H

H

H

PhPh

NB

minus

+

+

(CF3SO2)2N

20mol catalyst

16hoursDichloromethane minus78∘C

Scheme 12 See [250ndash256]

712 Shi Epoxidation Catalyst Tu et al reported a fructosederived ketone in efficient asymmetric epoxidation of trans-olefins (Scheme 13) [257] Epoxidation catalyst is able toepoxidize trans-alkenes and certain cis-alkenes with good toexcellent yields and selectivities [258 259] Marigo et alrsquosgroup reported an asymmetric organocatalytic epoxidationof 120572 120573-unsaturated aldehydes with environmentally friendlyoxidant hydrogen peroxide [260]

713 N-Heterocyclic Carbene (NHC) as Organocatalysts

7131 Rovis Catalyst The conjugate addition of an aldehydeto an 120572120573-unsaturated compound (Stetter reaction) is apractical methodology for the construction of 14-dicarbonylcompounds bearing quaternary stereocenters Triazoliumsalt in the presence of a base functions as an N-heterocycliccarbene organocatalyst (Figure 9) in highly enantioselectiveintramolecular Stetter reactions [261 262]

7132 Bode Catalyst Bodersquos studies on NHCs (Figure 10)mainly involve catalytic generation of reactive speciessuch as enolates homoenolates and activated carboxylates

N-Mesityl substituent on an imidazolium or triazoliumNHCprecursor generates highly enantioselective annulations fromsimple starting materials under mild reaction conditions[263 264] In an interesting example the catalysts facilitatehighly enantioselective cyclopentene forming annulations ofsimple enals and activated enones [265] Redox esterificationsand amidations of 120572-functionalized aldehydes using achiralcatalyst are also reported [266] Uniting unique activationmodes of N-heterocyclic carbene (NHC) catalysts with theconcept of domino reactions a new fast-growing field cameinto the spotlight in last couple of years or so [267ndash269]

Domino Michaelaldol reaction between 2-mercapto-quinoline-3-carbaldehydes and enals was catalyzed by di-phenylprolinol silyl ether producing 2H-thiopyrano[23-b]-quinolines in excellent yields and enantioselectivities [270]Zhao et al reported studies on ldquocooperative NHC andrutheniun redox catalysisrdquo in the oxidative esterificationof aldehydes [271] Blanc et al reported NHC mediatedorganocatalytic one-pot allylstannation to generate syn-diols[272] With enals as starting aldehydes elegant cascadeprocesses have been developed using oxidative carbene catal-ysis [273ndash276] Over the last few years there are examplesreported in literature where various organocatalysts rally

16 Journal of Catalysts

O

Oxone

OO

O

O

OO

R1 R1

R3

R3

R2 R2H2OCH3CN

Scheme 13

F3C

N+

F3C

Brminus

CF3

CF3

Figure 8 See [176]

N

O

N

N

F

F

F

F

F

+BF4minus

Figure 9

domino reactions and attract their application in organicprocesses in industries [174 175 180 181 183]

Apart from the aforementioned organocatalysts thereare other organic systems which upon appropriate acti-vation function as catalysts in useful asymmetric synthe-ses [155ndash157] 12-Dicarbonyl compounds because of theiradjacent multiple reactive centers upon activation act asefficient pronucleophiles in asymmetric organocatalyzed

N

O

NN+

Clminus

Figure 10

sequential or domino transformations including CndashC or CndashN bond formation [277] Cyclopropenone catalyzed con-version of aldoximes and primary amides into nitriles ina one-pot mild reaction widens the scope of the utiliza-tion of cyclopropenones in organic synthesis [278] Thefirst asymmetric organocatalytic synthesis by phosphinecatalyzed [3+2] cycloaddition of allenoates onto fullereneis reported to yield enantiomerically pure carbocyclicfullerene derivatives under mild conditions [279] A new[3+2] cycloadditioncycloreversion strategy for organocat-alytic and thermally allowed carbonyl-olefin metathesis isreported [280] Recently a strong evidence for halogenbond based organocatalysis is reported for the reactionof 1-chloroisochroman with ketene silyl acetals [281] Acidcatalyzed asymmetric acetalizations of aldehydes are alsodescribed [282] beta-Isocupreidine catalyzed the enantios-elective Morita-Baylis-Hillman reaction of maleimides withisatin derivatives to form 3-substituted 3-hydroxyoxindolederivatives [283 284]

Recent advances in asymmetric catalysis resulted in uti-lizing the less discussed electrophilic properties of iminiumtype intermediates in complex annulations of indoles [285286] and also pyridines [287 288] Shibatomi and Narayamadiscussed the catalytic enantioselective 120572-chlorination of car-bonyl compounds and stereospecific substitution reactions ofthe resulting optically active alkyl chlorides [289]

Though there is no relation between the developmentof two different fields of organocatalysis and gold catalysis

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

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[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

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[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

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[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

Journal of Catalysts 5

Table 3 Comparison among organometallic catalysts enzyme catalysts and organocatalysts

Organometallic catalyst Enzyme catalyst Organocatalyst

Wide substrate scope high catalyticactivity involving tedious processpotential heavy metal pollution

Limited substrate scope highselectivity and catalytic activity

usually single enantiomer

Robust inexpensive readily available nontoxic inert towardmoisture and oxygen method especially attractive for the

preparation of compound that do not tolerate metal contamination(pharmaceutical products)

Table 4 Advantages and disadvantages of organocatalysts

Advantages DisadvantagesEasy preparation or availability High catalyst loadingEasy handling inert towards moisture(water) and air (oxygen) Relatively premature field

Easy scale-upNo metal contaminationEasy screeningUseful in complex (steric) reactions

has steadily increased following the widespread utility ofaluminosilicate zeolites [48ndash51] titanosilicates [52 53] andaluminium phosphates [54 55]

In industries research endeavours are mainly devotedtowards the study and development of zeolites or zeoliticmaterials with several attractive features such as cat-alytic active site(s) large surface area zeolitic pore wallsand pore size control The synthesis and characteriza-tion of the crystalline aluminosilicate materials with tun-able meso-microporosity and their strong acidity havepotentially important technological implications for shape-selective catalytic reactions ion exchange and adsorption oforganic compounds [56ndash58]Thepore diameters can be finelychosen tuned and utilized for exhibiting shape-selectivecatalysis depending on the molecular shapesize of organicreactant and product The widespread interest has beendeveloped in the zeolitic science towards the developmentand discovery of zeolites with desired characteristics sinceconventional zeolites lack fine tuning of their properties toacidbase and redox or bifunctional or multifunctional prop-erties Organic functionalization adds new catalytic functionsto zeolites [59]

Zeolites are microporous crystalline aluminosilicateswith unique properties used for many processes Zeolitespossess acid sites that are associated with the tetrahedralaluminium atoms in their framework and therefore theamount of acidity depends on the aluminium content ofthe zeolite Zeolite acid catalysts have wide application inindustrial processesThe introduction of Y-zeolites to replaceamorphous silica-alumina in fluidized catalytic cracking(FCC) and in hydrocracking processes in the early 1960rsquos wasa breakthrough application in acid catalysis With the everincreasing research efforts in this area leading to discoveriesof new structures and modification schemes by academicand industrial laboratories the potential of solid acids hasevolved tremendously However with the exception of theZSM-5 Mordenite and to some extent Beta zeolite very few

of these structures have been applied in industrial processesto any significant extent Yet one can account for relativelyfew applications to the huge number of new materialsintroduced Notable examples are the reported uses of SAPOsin lube dewaxing and in natural gas to olefin technologiesand MCM-22 in aromatics alkylation The zeolite structureswith large-porebimodal porosity and tunable acidity canbe a remarkable benefit for catalytic processes in industriesWithin industrial catalysis there are constant innovation andchanging approaches to provision of selective economicallyviable and environmentally benign processes

Recently enormous growth in the chemical diversity ofinorganic materials with transition-metal incorporation innew compositional domains has also been explored dueto their potential application in adsorption and catalysisInorganic polymers transition metal phosphates and metal-organic frameworks [39 40] with novel catalytic electronicmagnetic and unique structural properties are particularlypromising candidates [60ndash64] The mesoporous structurewith strong acidity can be a remarkable benefit for catalyticreactions involving large organic molecules in which diffu-sion constraints andor adsorption of reactantmolecules ontothe strong acid sites are the main concern A lot has beenreported about the pathways to developmesostructured silica[65] In terms of surface functionalization the performanceof mesoporous silica has been polished by several methodssuch as metal incorporation [66] metal deposition [67]grafting by organic functional groups [68] and immobiliz-ing metal complex [69] New approaches to synthesis andcharacterization of bimodal that is micro-mesoporous andor meso-macroporous materials might assist us in under-standing the phenomena of diffusion confinement effectsselectivity and so forth [47]

5 Organocatalysis A NovelSynthetic Philosophy

The term ldquoorganocatalystrdquo is a concatenation of the wordsldquoorganicrdquo and ldquocatalystrdquo The definition corresponds to a lowmolecular weight organicmolecule which in substoichiomet-ric amounts catalyzes a chemical reactionThe organocatalystcould be achiral or chiral and could be composed of CH N S and P Organocatalysis has several advantages notonly because of its synthetic range but also for the economicreasons The absence of metal in organocatalyst brings anundeniable advantage considering both the principles ofldquogreen chemistryrdquo and the economic point of view (Figure 3)

Nowadays organocatalysis is one of the hot researchtopics in advanced organic chemistry It is a novel syn-thetic philosophy and mostly an alternative to the prevalent

6 Journal of Catalysts

N

H

L-ProlineN

N

DMAP

OH

Nobin

N

NO

H

MacMillanrsquos catalyst

O

N

HO N

Quinine

CO2H

NH2

∙ ∙

Figure 3 Few famous examples of organocatalysts L-proline DMAP quinine and MacMillanrsquos catalyst

transition metal catalysis Organocatalysts are often basedon nontoxic organic compounds originating from biologicalmaterials Organocatalysts can be Lewis bases Lewis acidsBroslashnsted bases and Broslashnsted acids Most of the organocatal-ysis reported so far are explained by Lewis base mechanismThe Lewis base mechanism can be simplified as follows

Step I Lewis base for example cinchona alkaloidinitiates catalysis via a nucleophilic addition to ordeprotonation of the substrateStep II the chiral intermediate undergoes reactionStep III separation of product(s) from the catalystoccursStep IV regeneration of the catalyst and its availabilityfor a new catalytic cycle occurs

There are many organocatalytic reactions that need a secondmechanism to explain the catalytic cycle involved This iscalled bifunctional organocatalysis in which the organocata-lyst possesses not only a Lewis base (nitrogen or phosphorusatom) but also a Broslashnsted acidic site There is a lot to be donein redox catalysis and in exploitation of the synergetic effect ofdifferent catalytic active sites within one organic compoundor material

Some advantages of organocatalysts include the following

(i) Reactions performed by organocatalysts have poten-tial application in large scale production in industries

(ii) Scope organic reactions occur which are not inpractice and not possible by other forms of catalystsfor example asymmetric synthetic processes

(iii) PriceAvailability Low cost alkaloids natural aminoacids L-proline tartaric acid and so forth are easilyavailable and are economically attractive

(iv) Recycling issues immobilization of the catalyst is thesimplest way to recover it

(v) Some of the examples include bioderived andbiodegradable organocatalysts

(vi) Organocatalysts work at mild reaction conditions(vii) Sometimes the final products of reactions contain

high levels of metal contamination derived from cat-alyst degradation phenomena which pose a seriousdrawback if the metal is toxic for pharmaceutical andfood industries Absence of transition-metal bringsorganocatalysis at the heart of greening chemistry

Organocatalysis can be categorized into our different typesas follows

Type-I activation of the reaction based on the nucle-ophilicelectrophilic properties of the catalyst is done(Scheme 1)

Type-II organic molecules form reactive intermedi-ates The chiral catalyst is consumed in the reactionand requires regeneration in parallel catalytic cycle asit is reported in Scheme 2

Type-III phase transfer reactions occur The chiralcatalyst forms a host-guest complexwith the substrateand shuttles between the standard organic solvent anda second phase

Journal of Catalysts 7

O

O

O

O

OOH

100

N

H

3mol L-proline

DMF 20∘C 20h

CO2H

Scheme 1 Hajos and Parrish [70]

O

O

OOO

O

O

30mol catalyst

30 H2O2 (3 equivalent)

CH3CNndashK2CO3

R1R3

R2

R1R3

R2

Scheme 2 Shu and Shi [71]

Catalytic enantioselective enolate alkylation(Scheme 3) occurs

Type-IV molecular-cavity-accelerated asymmetrictransformations occur in which the catalyst mayselect from competing substrates depending on sizeand structure criteria (Scheme 4)

6 Discovery and the History ofOrganocatalysis

Liebigrsquos synthesis of oxamide from dicyan and water is thefirst organocatalytic reaction reported [74] Acetaldehydewasfurther identified to behave as the then-named ldquofermentrdquonow called as enzyme Dakin in 1909 demonstrated that ina Knoevenagel type condensation between aldehydes andcarboxylic acids or esters with active methylene groups theamine catalysts could be mediated by amino acids [75]Langenbeck is remembered for developing enamine typereactions and the application of simple amino acids andsmall oligopeptides as catalysts [76ndash78] Natural products inparticular strychnine brucine and cinchona alkaloids andamino acids (including short oligopeptides) were amongthe first organic catalysts tested [79 80] Though the fieldof small-molecule catalysts seems very simple there are

evidences that prove their pivotal role in synthesis of buildingblocks for life L-Alanine andL-isovaline capable of catalyzingcertain CndashC bond formation reactions had been found onmeteorites [81]

An asymmetric transformation with an organic moleculewas published in 1912 by Bredig and Fiske [82] Pracejusapplied cinchona alkaloids in the asymmetric conversionof ketenes to (S)-methyl hydratropate [83 84] An initialresearch byYamadaampOtaniwas important too [85]The sev-enties brought anothermilestone Hajos and Parrish reporteda L-proline catalyzed Robinson annulation in excellent enan-tioselectivities [70 86 87] Eder et al reported organocat-alytic aldol reactions in good enantioselectivities [88] Tosummarize in 1970s Hajos and Parrish and independentlyEder Sauer and Wiechert published a series of papers andpatents involving such organocatalytic transformations Theasymmetric synthesis of enediones useful building blocksin natural product total syntheses was achieved (S)-Prolineinduced the formation of (S)-enediones

Two mechanisms [89] were proposed (1) involving theformation of a carbinolamine intermediate followed by thedisplacement of the proline moiety by nucleophilic attackof the enol from the side chain ketone (2) involving anenaminium intermediate acting as a nucleophile in the CndashCbond formation with concomitant NHsdot sdot sdotO hydrogen trans-fer Wynberg firstly published various 12 and 14 additionscatalyzed by cinchona bifunctional organocatalysis [90ndash92]

8 Journal of Catalysts

N

O

Ph

Ph

Ph

Ph

N

O

OO

O

81 96 eeO

O

O

O

H N

Chiral quaternary ammonium catalyst10mol catalyst

CH2Cl2BrH2C

Ot-Bu

Ot-Buminus78

∘C 24h

+

Brminus

CsOHmiddotH2O

Scheme 3 Corey et al [72]

O

BOCHN BOCHN

OO OH

Nu

OH

(2) Nu

(1) Polymer

HO

N

HN

HO

O

O

OH

NO2

NO2

+

Scheme 4 Sellergren et al [73]

All these research endeavours were not carefully looked intotill List et al reported in 2000 proline catalyzed aldol reactionin good enantiomeric excesses [93 94]

Asymmetric catalysis constitutes one of the most impor-tant subjects in synthetic organic chemistry Asymmetricsynthesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the application of such methodologies inchemical industry is rather limited due to the high cost ofchiral ligands and noble metals used in such transformationsMoreover the pharmaceutical entities and food industryproducts do not tolerate a contamination of even traces ofany such metals for that matter Synthesis of chiral drugshas a major financial impact in pharmaceutical industrieson a global scale Different enantiomers or diastereomers ofa molecule often have different biological activity Most ofthe drugs might be soon sold as single enantiomers in thecoming years There is a huge demand for organocatalystsleading to 100 yield 100 ee of the desired product Theneed from chemical industry especially pharmaceutical forreliable asymmetric transformations of molecular skeletonsis higher than ever Therefore asymmetric organocatalysisis in a process of attaining maturity into a very powerful

practical and broadly applicable methodological approach inthe catalytic asymmetric synthesis

7 Some Examples and Developments inCatalyst Structural Variants

Following are the famous examples of organocatalysts

71 Proline and Derivatives The proline catalyzed Robinsonannulation was one of the earliest examples of an enantios-elective reaction using an organic catalyst [85] This aminoacid contains both a nucleophilic secondary amino groupand a carboxylic acid moiety functioning as a Broslashnstedacid The availability of proline in both enantiomeric formsbrings advantages over enzymatic methods Arguably thefirst example of proline catalyzed asymmetric aldol reactionis reported by Hajos and Parrish [70 86 87] The Wieland-Miescher ketone is a useful synthetic building block forwhich a classical asymmetric procedure using (S)-prolinewas published forty years ago [88] It is quite significant thatthe first efficient organocatalyzed asymmetric reactions weredescribed by Hajos amp Parrish [86 87] and by Eder et al [88]

Journal of Catalysts 9

both teams from pharmaceutical companies (Hoffmann-la-Roche and Schering) The asymmetric synthesis of theWieland-Miescher ketone is also based on proline andanother early application was one of the transformations inthe total synthesis of erythromycin by Woodward et al [95]Proline is recognized as a versatile organocatalyst of thesetimes (Scheme 5)

In fact the renewal of proline catalyzed transformationsin early 2000 by D W C MacMillan Carlos F Barbas IIIand Benjamin List saw the renaissance of the concept and itwas the starting point of the word ldquoorganocatalysisrdquo ProfessorAhrendt group reported the first enantioselective organocat-alytic Diels-Alder reaction [96] Proline was identified asan effective organocatalyst for asymmetric aldol reaction[97] The catalytic asymmetric 120572-alkylation of aldehydeswas reported by Vignola and List [98] This transformationhad been accomplished with the help of covalently attachedauxiliaries 120572-Methyl L-proline exhibits higher enantioselec-tivities and improved reaction rates when compared to L-proline In recent years proline especially L-proline hasbeen used to catalyze essential transformations used in thefine chemical and pharmaceutical industries such as thedirect asymmetric aldol reactions [99ndash107] Diels-Alder reac-tions Michael reactions [108ndash115] Mannich reaction [116ndash122] Multicomponent reactions [123 124] and 120572-amination[125] 120572-aminoxylation [126ndash128] 120572-oxyaldehyde dimer-ization [100] 120572-functionalization of carbonyl compounds[129] and 120572-alkylation of aldehydes [130] Organocat-alytic cyclopropanation reactions were typically performedusing catalyst-bound ylides However Kunz and MacMil-lan demonstrated that activation of olefin substrates usingcatalytic (S)-(minus)-indoline-2-carboxylic acid is a viable routefor the formation of highly enantioenriched cyclopropanes[131]

Prof K A Joslashrgensen has made an importantbreakthrough in asymmetric synthesis by developing (R)-and (S)-120572120572-bis[35-bis(trifluoromethyl)phenyl]-2-pyrroli-dinemethanol trimethylsilyl ether as excellent chiral organ-ocatalysts in the direct organocatalytic 120572-functionaliza-tion of aldehydes Diarylprolinol silyl ether reagents werefound to catalyze CndashC CndashN CndashO CndashS and CndashHal bondforming reactions [132ndash138] Cascade or domino reactionsswiftly construct complex biologically important compoundsand minimize waste and also the laboratory operations [139]Endersrsquo group developed proline derived organocatalyst fora chemo- diastereo- and enantioselective three-componentdomino reaction to yield tetrasubstituted cyclohexenecarbaldehydes [140] The four stereogenic centers aregenerated in three consecutive CndashC bond formations thatis MichaelMichaelaldol condensation with high diastereo-and complete enantiocontrolThe synthesis of polyfunctionalcyclohexene building blocks involving proline catalytic stepsis reported in this domino reaction

Though this segment of our review is dedicated to prolineas an important class of organocatalysts it would also be agood place to acknowledge the research contributions fromprofessor Ahrendt et al to the field of organocatalysis [96 99100 103 127 131 141ndash150]

Heterogenized Proline An explosion of research articles inthe area of homogeneous organocatalysis occurredwithin thelast decade or so In addition to the initial proline catalyzedreactions the word ldquoorganocatalysisrdquo covers nowadays manyotherwell-knownorganocatalysts and organic reactions Pro-line immobilized onto some sort of inorganic support pavesthe way towards heterogenization of other organocatalysts[151ndash153] A simple and efficient synthesis of polystyrene-supported proline and prolinamide is reported Polystyrene-supported proline catalyzes the asymmetric aldol reactionbetween cyclohexanone and substituted benzaldehydes inwater High yields diastereoselectivities and ee values havebeen observedThe versatility of this resinwas also confirmedby selenenylation of aldehydes Both proline and prolinamideresins gave high yields Recycling studies showed that theproline resin performs as better heterogeneous organocat-alyst as compared to the prolinamide resin [153] An aldolreaction catalyzed by proline functionalized silica gel wasinvestigated in continuous flow microreactors by reaction-progress kinetic analysis and nonlinear chromatography[154]

Though the research community advocates asymmetricsynthesis for industrial application organocatalysts havebeen seldom applied in industry due to insufficient efficiencyand the difficulties in catalyst separation and recycling[155ndash161] The concept of heterogenizing organocatalyst onsupports combines the advantages of both homogeneousorganocatalysis and heterogeneous recycling Though thismight seem simple and present opportunities in indus-trial chemical processes the research in heterogeneousorganocatalysis demands a multidisciplinary approach byidentifying catalytic activity upon bonding organocatalystcovalently to the support understanding noncovalent inter-action as structure-reactivity and conformation decidingfactor taking into consideration the characteristic propertiesof the supports confinement effects if any and so forthSome recent examples will be described on the applicationsof supported proline as organocatalysts for their preindus-trialization study The latter half of this review in generalirons out the detailed discussion on key trendswith examplesscope challenges and ldquogreenrdquo applications of heterogeneousorganocatalysts

72 Other Amino Acids Barbas and coworkers found theproteinogenic amino acid tryptophan (Figure 4) to be anexcellent organocatalyst for the Mannich reaction of hydrox-yacetone with a variety of imines performed in DMF leadingthe desired anti-amino alcohols in excellent diastereoselec-tivities (up to gt19 1) and enantioselectivities (90ndash98 ee)Similarly t-butyl protected threonine catalyzed the aldolreaction of hydroxyacetone and various aldehydes in NMP togive the corresponding syn-aldol adducts in high yields andgood to excellent enantio- and diastereoselectivities [162]Zhao et al reported [163] the development of an aminoacid based small molecule capable of promoting asymmetricmonosilylation of meso-12-diols Furthermore the catalystcan be recycled with equal efficiency Three-componentreaction involving condensation of aldehyde 13-carbonyl

10 Journal of Catalysts

NH

OH

OH

O

O NHPh

O PhH

H

ON

NH

H

O OH

CO2BnCO2Bn

NO2

R1 R2

Scheme 5

NH

OH

O

H2N

Figure 4 L-Tryptophan

compound and (thio)urea is known as Biginelli reactionVarious organocatalysts such as tartaric acid oxalic acidcitric acid and lactic acid were found effective in producingBiginelli products [164ndash172]

Because of the ldquoprivilegedrdquo green nature of this fieldit has become an obligation for scientific community andacademic institutions to be mindful and teach this branchof catalysis to students and also keep it as a driving force inthe generation and dissemination of knowledge in pursuitof efficient synthetic methodologies and processes usingorganocatalysts The synthesis of new chiral building blocksor complex molecular structures involving organocatalyticstep(s) is being reported almost every day in scientificliterature As it is not possible here to discuss all the catalystsindividually in detail the author decides to present salientdevelopments in organocatalysis and allied research areas

Synthesis of prochiral cyclohexanones by amine cat-alyzed self-Diels-Alder reactions of 120572120573-unsaturated ketonesin water brought coupled the concept of green chemistry

with catalysis Useful asymmetric heterodomino reactionsfor the highly diastereoselective synthesis of symmetri-cal and nonsymmetrical synthons of benzoannelated cen-tropolyquinanes were reported [173 174]

In recent years trials are being made by using aminoacids especially L-proline to catalyze essential transforma-tions in the fine chemical and pharmaceutical industriesTheinterest in this field has thus increased spectacularly in the lastfew years However organocatalytic methods often requirecatalyst loadings as high as 30mol for the achievement ofhigh conversions in reasonable reaction times [175] Somecritics suggest that low turnover numbers might limit thepotential uses of organocatalysis for industrial applicationsProcess development and scale-up are being tested for severalorganocatalytic reactions confirming organocatalysis as avaluable tool for industrial scale solutions Scientists arereporting novel organocatalytic systems in various reputedinternational research journals and those catalysts exhibitvarious valuable functions derived from a variety of struc-tural ionicelectronic and chemical properties Broad varietyof efficient syntheses will contribute to an increasing numberof organocatalytic large scale reactions in the future Theorganocatalysts shall be used in various fields especially inasymmetric organic synthesis

73 Amine and Chiral Vicinal Diamines Proline and pyrro-lidine derivatives commonly known as Hayashi-Joslashrgensencatalysts in the form of ferrocenyl pyrrolidine are appliedas organocatalyst wherein the ferrocene moiety controls theconformational space and a simple alkyl group effectivelycovers a face of the derived enamine (Figure 5) [180]

Journal of Catalysts 11

R

RNR

REthanol rt

N

O

H

N

R R

+

10mol catalyst

R1

R1

R1R2

R3H2N

middotTfOH

Scheme 6

H NH

O

R

trans H N

O

H

RCis

Reactive conformation

Si

O

H

R

H

Ph

O

Ph

HO

SiCl3 Cl3

Scheme 7

Sulzer-Mosse and Alexakis reported chiral amines cat-alyzing asymmetric conjugate addition to nitroolefins andvinyl sulfones via enamine activation [181]

A bifunctional H-bond directing aminocatalytic systemis found to achieve high stereo- and regiocontrol overdienamine mediated hetero-Diels-Alder reaction [183]

Though amine catalysis is constructing a wide varietyof chiral scaffolds in asymmetric synthesis organocatalysiswith amines for nonasymmetric transformations is alsodeveloping very fast [184 185] The [2+2] cycloaddition ofenals with nitroalkenes is catalyzed by a chiral secondaryamine in the presence of an achiral thiourea for the enantio-and diastereoselective synthesis of highly functionalizedcyclobutanes Mechanistically two consecutiveMichael reac-tions proceed through an unprecedented combination ofdienamineiminium activation mode [186] The reactionengineering of dienamine catalysis for single-step synthesesof highly functionalized molecules such as natural productsor bioactive compounds is reviewed in literature [187]

Chin and coworkers have recently reported some pre-liminary theoretical and experimental studies for convertinga parent diamine into other chiral vicinal diamines Thesediamines can be handy as ligands for chiral catalysts or theycanmake chiral heterocyclic rings and betalactams [188ndash190]

There are some CndashC bonds forming reactions catalyzed bysuch diamine organocatalysts (Scheme 6) [191]

74 Amides Recently the synthesis of multifunctional or-ganocatalysts easily obtained by the condensation of (S)-proline with 2-aminopyridine 26-diaminopyridine or 2-aminoimidazole is reported These chiral prolinamides pro-moted the aldol condensation between cyclohexanone anddifferent aromatic aldehydes (up to 98ee) and also catalyzedDiels-Alder and Michael reactions [192 193]

Rationally designed pyrazole amides function as Michaeldonors in urea catalyzed asymmetric Michael reactions withexcellent chemical and optical yields [194]

A structure-activity relationship with regard to for-mamides as organocatalysts is exploredThis study highlightsthat the cis-conformation of secondary formamides is thereactive conformation in the allylation of aldehydes withallyltrichlorosilane (Scheme 7) [195]

75 Imidazolidinones A certain class of imidazolidinonecompounds (also called MacMillan imidazolidinone organ-ocatalysts) function as catalysts for many asymmetric organictransformations such as asymmetric Diels-Alder reactions

12 Journal of Catalysts

O

N

O

H

O

Up to 97 ee

OHH

N

NO

H20 mol catalyst

CHCl3 minus30∘C

C2H5O OC2H5

R1

R1

R2

R2

+

middotCF3CO2H

Scheme 8 Ouellet et al [202]

R

R

N

One favoured conformer

High enantioselectivity

R = alkyl

Fe

Figure 5

The original such compound was derived from the chi-ral biomolecule phenylalanine [196 197] The first highlyenantioselective organocatalytic Diels-Alder reaction usinga chiral organocatalyst was reported in MacMillanrsquos pio-neering work where the activated iminium ion formedthrough condensation of the imidazolidinone and an 120572120573-unsaturated aldehyde reacted with various dienes to give[4+2] cycloadducts in excellent yields and enantioselectivi-ties Ahrendt et al reportedmany other asymmetric reactionssuch as the 13-dipolar cycloadditions Friedel-Crafts alky-lations 120572-chlorinations 120572-fluorinations and intramolecularMichael reactions usingMacMillanrsquos organocatalysts [96 150198ndash201]

Ouellet et al also reported the combination of imida-zolidinone organocatalyst and Hantzsch ester to facilitatethe first enantioselective organocatalytic hydride reductionof 120572120573-unsaturated aldehydes (Scheme 8) [202 203] Thisimitated naturersquos stereoselective enzymatic transfer hydro-genation with NADH cofactor

Noncovalent interaction is a structure-reactivity andconformation deciding factor which requires immediateattention for understanding organocatalysis [204] Of specialinterest would be the identifying and understanding of othernoncovalent interactions such as charge transfer [205] pndashp stacking immobilization [206] and adsorption or entrap-ment of organocatalysts in nanomaterials [207]

Homogeneous and HeterogenizedMacMillanrsquos OrganocatalystAn asymmetric Diels-Alder reaction was catalyzed with highefficiency and recyclability by a soluble ldquoself-supportedrdquochiral organosilica polymer with embedded imidazolidinonecatalytic moieties [208]

76 Chiral Phosphoric Acids BINOL derived phosphoricacids catalyze nucleophilic addition reactions to imine sub-strates A direct Pictet-Spengler reaction was reported usinga geminally disubstituted tryptamine organocatalyst to formisoquinolines in excellent yield and enantiomeric excess[209] Phosphoric acid catalyzing the reduction of an iminewith a Hantzsch ester in good enantiomeric excess was firstlyreported by Rueping et al Hoffmann et al reported animprovement to this methodology [210 211]

Storer research group reported a one-pot reductive ami-nation of a range of methyl ketones and aryl amines [212]Reductive amination of 2-butanone over silylated phosphoricacid MacMillan TiPSY catalyst was obtained with goodenantiomeric excess

Zhou and List published on the use of chiral Broslashnstedacid (R)-TRIP for highly enantioselective synthesis of phar-maceutically relevant 3-substituted cyclohexylamines from26-diketones wherein the achiral amine substrate acceleratesthe cascade reaction before getting incorporated into the finalproduct (Scheme 9) [213]

Rowland et al reported VAPOL derived phosphoric acidcatalyzed addition of sulfonamides to BOC protected arylimines and protected aminals in excellent enantioselectivities[214]

The (R)-TRIP catalyzed the aza-Diels-Alder reaction ofaldimines with Danishefskyrsquos diene to yield piperidinonederivatives with high enantioselectivity Addition of aceticacid was found to improve both reactivity and enantiose-lectivity [215] Six chemical bonds five stereogenic centersand three cycles were formed in one-pot four-componentUgitype reaction catalyzed by a chiral BINOLderived phosphoricacid [216] BINAP is one of the earliy commercially appliedligands in industrial catalysis [217] Amicroporous recyclableheterogeneous catalyst offering excellent enantioselectivitywas made from a 111015840-binaphthalene-221015840-diol (binol) derivedphosphoric acid chloride and was found as active as thecorresponding homogeneous catalyst [218]

Journal of Catalysts 13

O

O

Ph

OEt HH

Ph

HN

OEt

i-Pr

i-Pr

i-Pri-Pr

i-Pr

i-Pr

O

OP O

OH

EtO2C CO2Et

CyclohexaneMS 5 A 50∘C

NH2

(R)-TRIP (10mol)

82 dr = 24 1 er = 98 21 22

Scheme 9 Zhou and List [213]

NO

N NHH N

HO

S

N

H R

BocO-PrTBS-O

Pr-O

HN

Boc

5mol catalyst+

t-Bu

t-Bu t-Bu

(2) TFA 2min(1) Toluene minus30∘C 48hr

86ndash98 ee

Scheme 10

HO OH

O O

Figure 6

77 Chiral Diols Huang et al reported on use of TADDOLs(Figure 6) as Broslashnsted acid organocatalysts in highly stereos-elective hetero-Diels-Alder reactions [219]

The 120572-amination of carbonyl compounds has also beenaccomplished by using the 1-naphthyl TADDOL derivative asa Broslashnsted acid organocatalyst [220] McDougal and Schausreported asymmetric Morita-Baylis-Hillman reaction that

is the addition of cyclohexenone to different aldehydescatalyzed by octahydro-BINOL derived Broslashnsted acid [221]

78 JacobsenThioureas ProfessorsVachal and Jacobsen iden-tified chiral thioureas (Figure 7) as versatile and effectiveorganocatalysts 1mol of the thiourea was reported to havecatalytic activity in the hydrocyanation (Strecker reaction) ofboth aldimines and ketoimines with very high enantioselec-tivities [222]

Imine hydrophosphonylation particularly effective withelectron-withdrawing ester substituents on the phosphatetook place in the presence of 10mol of the catalyst [223]Mannich reactions of BOC protected imines have also beenreported (Scheme 10) [224] with excellent yields and enan-tioselectivities and show heterocyclic substrate tolerance

A variant of thiourea organocatalyst was found to catalyzethe cyanosilylation of ketones and aldehydes in high yieldsand enantiomeric excesses [225] Thiourea organocatalystwas put to use in the acyl-Pictet-Spengler reaction to formtetrahydro-120573-carbolines [226] The acyl-Mannich reactionproviding a route to enantioenriched heterocycles from

14 Journal of Catalysts

N N N

H H NO H

HO

O

O

O

t-Bu

t-Bu

t-Bu

Figure 7

aromatic starting materials and trichloroethyl chloroformate(TrocCl) is also catalyzed by the thiourea organocatalyst[227] Bifunctional thiourea-base catalyzed double-Michaeladdition of benzofuran-2-ones to dienones is reported forthe synthesis of optically enriched spirocyclic benzofuran-2-ones [228] In another interesting example benzoylthiourea-pyrrolidine catalyst was synthesized and used in the asym-metric Michael addition of ketones to nitroalkenes [229]

Primary amine-thioureas were improvised to catalyzedifficult Michael reactions synthesizing (S)-baclofen (R)-baclofen and (S)-phenibut [230]

79 Cinchona Alkaloids The cinchona alkaloids catalyzemany useful processes with high enantioselectivities Asym-metric phase transfer catalysis (PTC) presents a ldquogreenrdquoalternative to homogeneous synthetic organic chemistrymethodologies Cinchona alkaloids are synthetically mod-ified for their usage in asymmetric PTC O-Alkyl N-arylmethyl derivatives of cinchona alkaloid led highly enantiose-lective alkylation of glycine imines to generate 120572-amino acidderivatives And for the same reaction dimeric cinchonaalkaloid obtained 97ndash99 enantiomeric excess [231 232]Cinchona alkaloids deprotonate substrates with relativelyacidic protons forming a contact ion pair between the result-ing anion and protonated amineThis interaction generates achiral pool around the anion and facilitates enantioselectivereactions with electrophiles The control over the formationof quaternary asymmetric centers is essential to obtain highenantiomeric excesses The 120572-functionalization of ketones(Scheme 11) by the addition of TMSCN to the correspondingcyanohydrin in excellent yield and enantiomeric excess iscatalyzed by the (DHQD)

2AQN catalyst [233]

Increasingly remote stereocenters are being targeted inasymmetric aminocatalysis Organocatalytic allylic amina-tion presents an alternative to the conventional palladiumcatalyzed methodology Amination at the remote 120574-positionusing (DHQ)

2PYR forms highly functionalized amine com-

pounds [234]Bella and Joslashrgensenrsquos reported the first enantioselective

conjugate addition of 120573-diketones to both aromatic andaliphatic alkynones using (DHQ)

2PHAL catalyst [235] Cin-

chona based primary amine catalysis is found to offer high

efficiency and reliability in the asymmetric functionalizationof carbonyl compounds [236 237] Organocatalysts derivedfrom cinchona alkaloids function as Lewis base catalyst inthe cyclizations of allenoates with electron deficient olefinsand imines and emerged as important synthetic tool inthe preparation of biologically active and pharmaceuticallyinteresting cyclic compounds including natural products[238] Recently cinchona thioureas have been reported forthe first time as catalysts in the area of asymmetric oxi-dations [239] Cinchona and cinchonidine derived catalystsperform asymmetric direct aldol reaction of pyruvic aldehydedimethyl acetal with isatin derivatives [240] Likewise thereare various other examples reported where cinchona or itsvariants are used as organocatalysts for syntheses of variousbiologically important molecules [241ndash246]

710 Maruoka Phase Transfer Catalysts The chiral catalystforms a host-guest complex with the substrate and shuttlesbetween the standard organic solvent and a second phaseexample catalytic enantioselective enolate alkylation [72]As we know chiral quaternary ammonium catalysts can beuseful in asymmetric synthesis Kitamura et al reported C2-symmetric ammonium salts catalyzing monoalkylation ofglycine derived Schiff bases with alkyl halides to synthesize120572-alkyl-120572-amino acids under remarkably low catalyst loadings[247ndash249]

Utilizing the solubility of aqueous quaternary ammoniumsalts into organic solvents professor Maruoka developedspirotype chiral ammonium salt with two binaphthyl ringsas a novel chiral phase transfer catalyst Figure 8 depicts theorganocatalyst for direct asymmetric aldol reaction of 120573-hydroxy-120572-amino acid derivative

711 Oxazaborolidines Chiral oxazaborolidines (known asCBS oxazaborolidines after Corey Bakshi and Shibata)catalyze the reduction of prochiral ketones imines andoximes to produce chiral alcohols amines and amino alco-hols respectively in high yields and excellent enantiomericexcesses The chiral Lewis acid generated from o-tolyl-CBS-oxazaborolidine after protonation with trifluoromethanesul-fonimide is very useful in the enantioselective Diels-Alderreaction (Scheme 12) [250ndash256]

Journal of Catalysts 15

O NC OTMSN

OH

N

N

OH

N

OO

2 to 20mol catalyst

TMSCN CHCl3

OC2H5

OC2H5

OC2H5

OC2H5

H3CO

C6H5C6H5

OCH3

Scheme 11 Tian et al [233]

OO

O

OO

II

CH3CH3

CH3

H3C

H3C TIPSOTIPSO

H

H

H

PhPh

NB

minus

+

+

(CF3SO2)2N

20mol catalyst

16hoursDichloromethane minus78∘C

Scheme 12 See [250ndash256]

712 Shi Epoxidation Catalyst Tu et al reported a fructosederived ketone in efficient asymmetric epoxidation of trans-olefins (Scheme 13) [257] Epoxidation catalyst is able toepoxidize trans-alkenes and certain cis-alkenes with good toexcellent yields and selectivities [258 259] Marigo et alrsquosgroup reported an asymmetric organocatalytic epoxidationof 120572 120573-unsaturated aldehydes with environmentally friendlyoxidant hydrogen peroxide [260]

713 N-Heterocyclic Carbene (NHC) as Organocatalysts

7131 Rovis Catalyst The conjugate addition of an aldehydeto an 120572120573-unsaturated compound (Stetter reaction) is apractical methodology for the construction of 14-dicarbonylcompounds bearing quaternary stereocenters Triazoliumsalt in the presence of a base functions as an N-heterocycliccarbene organocatalyst (Figure 9) in highly enantioselectiveintramolecular Stetter reactions [261 262]

7132 Bode Catalyst Bodersquos studies on NHCs (Figure 10)mainly involve catalytic generation of reactive speciessuch as enolates homoenolates and activated carboxylates

N-Mesityl substituent on an imidazolium or triazoliumNHCprecursor generates highly enantioselective annulations fromsimple starting materials under mild reaction conditions[263 264] In an interesting example the catalysts facilitatehighly enantioselective cyclopentene forming annulations ofsimple enals and activated enones [265] Redox esterificationsand amidations of 120572-functionalized aldehydes using achiralcatalyst are also reported [266] Uniting unique activationmodes of N-heterocyclic carbene (NHC) catalysts with theconcept of domino reactions a new fast-growing field cameinto the spotlight in last couple of years or so [267ndash269]

Domino Michaelaldol reaction between 2-mercapto-quinoline-3-carbaldehydes and enals was catalyzed by di-phenylprolinol silyl ether producing 2H-thiopyrano[23-b]-quinolines in excellent yields and enantioselectivities [270]Zhao et al reported studies on ldquocooperative NHC andrutheniun redox catalysisrdquo in the oxidative esterificationof aldehydes [271] Blanc et al reported NHC mediatedorganocatalytic one-pot allylstannation to generate syn-diols[272] With enals as starting aldehydes elegant cascadeprocesses have been developed using oxidative carbene catal-ysis [273ndash276] Over the last few years there are examplesreported in literature where various organocatalysts rally

16 Journal of Catalysts

O

Oxone

OO

O

O

OO

R1 R1

R3

R3

R2 R2H2OCH3CN

Scheme 13

F3C

N+

F3C

Brminus

CF3

CF3

Figure 8 See [176]

N

O

N

N

F

F

F

F

F

+BF4minus

Figure 9

domino reactions and attract their application in organicprocesses in industries [174 175 180 181 183]

Apart from the aforementioned organocatalysts thereare other organic systems which upon appropriate acti-vation function as catalysts in useful asymmetric synthe-ses [155ndash157] 12-Dicarbonyl compounds because of theiradjacent multiple reactive centers upon activation act asefficient pronucleophiles in asymmetric organocatalyzed

N

O

NN+

Clminus

Figure 10

sequential or domino transformations including CndashC or CndashN bond formation [277] Cyclopropenone catalyzed con-version of aldoximes and primary amides into nitriles ina one-pot mild reaction widens the scope of the utiliza-tion of cyclopropenones in organic synthesis [278] Thefirst asymmetric organocatalytic synthesis by phosphinecatalyzed [3+2] cycloaddition of allenoates onto fullereneis reported to yield enantiomerically pure carbocyclicfullerene derivatives under mild conditions [279] A new[3+2] cycloadditioncycloreversion strategy for organocat-alytic and thermally allowed carbonyl-olefin metathesis isreported [280] Recently a strong evidence for halogenbond based organocatalysis is reported for the reactionof 1-chloroisochroman with ketene silyl acetals [281] Acidcatalyzed asymmetric acetalizations of aldehydes are alsodescribed [282] beta-Isocupreidine catalyzed the enantios-elective Morita-Baylis-Hillman reaction of maleimides withisatin derivatives to form 3-substituted 3-hydroxyoxindolederivatives [283 284]

Recent advances in asymmetric catalysis resulted in uti-lizing the less discussed electrophilic properties of iminiumtype intermediates in complex annulations of indoles [285286] and also pyridines [287 288] Shibatomi and Narayamadiscussed the catalytic enantioselective 120572-chlorination of car-bonyl compounds and stereospecific substitution reactions ofthe resulting optically active alkyl chlorides [289]

Though there is no relation between the developmentof two different fields of organocatalysis and gold catalysis

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

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[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

[17] J R Anderson and K C Pratt Introduction To Characterisationand Testing of Catalysts Academic Press Sydney Australia1985

[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

6 Journal of Catalysts

N

H

L-ProlineN

N

DMAP

OH

Nobin

N

NO

H

MacMillanrsquos catalyst

O

N

HO N

Quinine

CO2H

NH2

∙ ∙

Figure 3 Few famous examples of organocatalysts L-proline DMAP quinine and MacMillanrsquos catalyst

transition metal catalysis Organocatalysts are often basedon nontoxic organic compounds originating from biologicalmaterials Organocatalysts can be Lewis bases Lewis acidsBroslashnsted bases and Broslashnsted acids Most of the organocatal-ysis reported so far are explained by Lewis base mechanismThe Lewis base mechanism can be simplified as follows

Step I Lewis base for example cinchona alkaloidinitiates catalysis via a nucleophilic addition to ordeprotonation of the substrateStep II the chiral intermediate undergoes reactionStep III separation of product(s) from the catalystoccursStep IV regeneration of the catalyst and its availabilityfor a new catalytic cycle occurs

There are many organocatalytic reactions that need a secondmechanism to explain the catalytic cycle involved This iscalled bifunctional organocatalysis in which the organocata-lyst possesses not only a Lewis base (nitrogen or phosphorusatom) but also a Broslashnsted acidic site There is a lot to be donein redox catalysis and in exploitation of the synergetic effect ofdifferent catalytic active sites within one organic compoundor material

Some advantages of organocatalysts include the following

(i) Reactions performed by organocatalysts have poten-tial application in large scale production in industries

(ii) Scope organic reactions occur which are not inpractice and not possible by other forms of catalystsfor example asymmetric synthetic processes

(iii) PriceAvailability Low cost alkaloids natural aminoacids L-proline tartaric acid and so forth are easilyavailable and are economically attractive

(iv) Recycling issues immobilization of the catalyst is thesimplest way to recover it

(v) Some of the examples include bioderived andbiodegradable organocatalysts

(vi) Organocatalysts work at mild reaction conditions(vii) Sometimes the final products of reactions contain

high levels of metal contamination derived from cat-alyst degradation phenomena which pose a seriousdrawback if the metal is toxic for pharmaceutical andfood industries Absence of transition-metal bringsorganocatalysis at the heart of greening chemistry

Organocatalysis can be categorized into our different typesas follows

Type-I activation of the reaction based on the nucle-ophilicelectrophilic properties of the catalyst is done(Scheme 1)

Type-II organic molecules form reactive intermedi-ates The chiral catalyst is consumed in the reactionand requires regeneration in parallel catalytic cycle asit is reported in Scheme 2

Type-III phase transfer reactions occur The chiralcatalyst forms a host-guest complexwith the substrateand shuttles between the standard organic solvent anda second phase

Journal of Catalysts 7

O

O

O

O

OOH

100

N

H

3mol L-proline

DMF 20∘C 20h

CO2H

Scheme 1 Hajos and Parrish [70]

O

O

OOO

O

O

30mol catalyst

30 H2O2 (3 equivalent)

CH3CNndashK2CO3

R1R3

R2

R1R3

R2

Scheme 2 Shu and Shi [71]

Catalytic enantioselective enolate alkylation(Scheme 3) occurs

Type-IV molecular-cavity-accelerated asymmetrictransformations occur in which the catalyst mayselect from competing substrates depending on sizeand structure criteria (Scheme 4)

6 Discovery and the History ofOrganocatalysis

Liebigrsquos synthesis of oxamide from dicyan and water is thefirst organocatalytic reaction reported [74] Acetaldehydewasfurther identified to behave as the then-named ldquofermentrdquonow called as enzyme Dakin in 1909 demonstrated that ina Knoevenagel type condensation between aldehydes andcarboxylic acids or esters with active methylene groups theamine catalysts could be mediated by amino acids [75]Langenbeck is remembered for developing enamine typereactions and the application of simple amino acids andsmall oligopeptides as catalysts [76ndash78] Natural products inparticular strychnine brucine and cinchona alkaloids andamino acids (including short oligopeptides) were amongthe first organic catalysts tested [79 80] Though the fieldof small-molecule catalysts seems very simple there are

evidences that prove their pivotal role in synthesis of buildingblocks for life L-Alanine andL-isovaline capable of catalyzingcertain CndashC bond formation reactions had been found onmeteorites [81]

An asymmetric transformation with an organic moleculewas published in 1912 by Bredig and Fiske [82] Pracejusapplied cinchona alkaloids in the asymmetric conversionof ketenes to (S)-methyl hydratropate [83 84] An initialresearch byYamadaampOtaniwas important too [85]The sev-enties brought anothermilestone Hajos and Parrish reporteda L-proline catalyzed Robinson annulation in excellent enan-tioselectivities [70 86 87] Eder et al reported organocat-alytic aldol reactions in good enantioselectivities [88] Tosummarize in 1970s Hajos and Parrish and independentlyEder Sauer and Wiechert published a series of papers andpatents involving such organocatalytic transformations Theasymmetric synthesis of enediones useful building blocksin natural product total syntheses was achieved (S)-Prolineinduced the formation of (S)-enediones

Two mechanisms [89] were proposed (1) involving theformation of a carbinolamine intermediate followed by thedisplacement of the proline moiety by nucleophilic attackof the enol from the side chain ketone (2) involving anenaminium intermediate acting as a nucleophile in the CndashCbond formation with concomitant NHsdot sdot sdotO hydrogen trans-fer Wynberg firstly published various 12 and 14 additionscatalyzed by cinchona bifunctional organocatalysis [90ndash92]

8 Journal of Catalysts

N

O

Ph

Ph

Ph

Ph

N

O

OO

O

81 96 eeO

O

O

O

H N

Chiral quaternary ammonium catalyst10mol catalyst

CH2Cl2BrH2C

Ot-Bu

Ot-Buminus78

∘C 24h

+

Brminus

CsOHmiddotH2O

Scheme 3 Corey et al [72]

O

BOCHN BOCHN

OO OH

Nu

OH

(2) Nu

(1) Polymer

HO

N

HN

HO

O

O

OH

NO2

NO2

+

Scheme 4 Sellergren et al [73]

All these research endeavours were not carefully looked intotill List et al reported in 2000 proline catalyzed aldol reactionin good enantiomeric excesses [93 94]

Asymmetric catalysis constitutes one of the most impor-tant subjects in synthetic organic chemistry Asymmetricsynthesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the application of such methodologies inchemical industry is rather limited due to the high cost ofchiral ligands and noble metals used in such transformationsMoreover the pharmaceutical entities and food industryproducts do not tolerate a contamination of even traces ofany such metals for that matter Synthesis of chiral drugshas a major financial impact in pharmaceutical industrieson a global scale Different enantiomers or diastereomers ofa molecule often have different biological activity Most ofthe drugs might be soon sold as single enantiomers in thecoming years There is a huge demand for organocatalystsleading to 100 yield 100 ee of the desired product Theneed from chemical industry especially pharmaceutical forreliable asymmetric transformations of molecular skeletonsis higher than ever Therefore asymmetric organocatalysisis in a process of attaining maturity into a very powerful

practical and broadly applicable methodological approach inthe catalytic asymmetric synthesis

7 Some Examples and Developments inCatalyst Structural Variants

Following are the famous examples of organocatalysts

71 Proline and Derivatives The proline catalyzed Robinsonannulation was one of the earliest examples of an enantios-elective reaction using an organic catalyst [85] This aminoacid contains both a nucleophilic secondary amino groupand a carboxylic acid moiety functioning as a Broslashnstedacid The availability of proline in both enantiomeric formsbrings advantages over enzymatic methods Arguably thefirst example of proline catalyzed asymmetric aldol reactionis reported by Hajos and Parrish [70 86 87] The Wieland-Miescher ketone is a useful synthetic building block forwhich a classical asymmetric procedure using (S)-prolinewas published forty years ago [88] It is quite significant thatthe first efficient organocatalyzed asymmetric reactions weredescribed by Hajos amp Parrish [86 87] and by Eder et al [88]

Journal of Catalysts 9

both teams from pharmaceutical companies (Hoffmann-la-Roche and Schering) The asymmetric synthesis of theWieland-Miescher ketone is also based on proline andanother early application was one of the transformations inthe total synthesis of erythromycin by Woodward et al [95]Proline is recognized as a versatile organocatalyst of thesetimes (Scheme 5)

In fact the renewal of proline catalyzed transformationsin early 2000 by D W C MacMillan Carlos F Barbas IIIand Benjamin List saw the renaissance of the concept and itwas the starting point of the word ldquoorganocatalysisrdquo ProfessorAhrendt group reported the first enantioselective organocat-alytic Diels-Alder reaction [96] Proline was identified asan effective organocatalyst for asymmetric aldol reaction[97] The catalytic asymmetric 120572-alkylation of aldehydeswas reported by Vignola and List [98] This transformationhad been accomplished with the help of covalently attachedauxiliaries 120572-Methyl L-proline exhibits higher enantioselec-tivities and improved reaction rates when compared to L-proline In recent years proline especially L-proline hasbeen used to catalyze essential transformations used in thefine chemical and pharmaceutical industries such as thedirect asymmetric aldol reactions [99ndash107] Diels-Alder reac-tions Michael reactions [108ndash115] Mannich reaction [116ndash122] Multicomponent reactions [123 124] and 120572-amination[125] 120572-aminoxylation [126ndash128] 120572-oxyaldehyde dimer-ization [100] 120572-functionalization of carbonyl compounds[129] and 120572-alkylation of aldehydes [130] Organocat-alytic cyclopropanation reactions were typically performedusing catalyst-bound ylides However Kunz and MacMil-lan demonstrated that activation of olefin substrates usingcatalytic (S)-(minus)-indoline-2-carboxylic acid is a viable routefor the formation of highly enantioenriched cyclopropanes[131]

Prof K A Joslashrgensen has made an importantbreakthrough in asymmetric synthesis by developing (R)-and (S)-120572120572-bis[35-bis(trifluoromethyl)phenyl]-2-pyrroli-dinemethanol trimethylsilyl ether as excellent chiral organ-ocatalysts in the direct organocatalytic 120572-functionaliza-tion of aldehydes Diarylprolinol silyl ether reagents werefound to catalyze CndashC CndashN CndashO CndashS and CndashHal bondforming reactions [132ndash138] Cascade or domino reactionsswiftly construct complex biologically important compoundsand minimize waste and also the laboratory operations [139]Endersrsquo group developed proline derived organocatalyst fora chemo- diastereo- and enantioselective three-componentdomino reaction to yield tetrasubstituted cyclohexenecarbaldehydes [140] The four stereogenic centers aregenerated in three consecutive CndashC bond formations thatis MichaelMichaelaldol condensation with high diastereo-and complete enantiocontrolThe synthesis of polyfunctionalcyclohexene building blocks involving proline catalytic stepsis reported in this domino reaction

Though this segment of our review is dedicated to prolineas an important class of organocatalysts it would also be agood place to acknowledge the research contributions fromprofessor Ahrendt et al to the field of organocatalysis [96 99100 103 127 131 141ndash150]

Heterogenized Proline An explosion of research articles inthe area of homogeneous organocatalysis occurredwithin thelast decade or so In addition to the initial proline catalyzedreactions the word ldquoorganocatalysisrdquo covers nowadays manyotherwell-knownorganocatalysts and organic reactions Pro-line immobilized onto some sort of inorganic support pavesthe way towards heterogenization of other organocatalysts[151ndash153] A simple and efficient synthesis of polystyrene-supported proline and prolinamide is reported Polystyrene-supported proline catalyzes the asymmetric aldol reactionbetween cyclohexanone and substituted benzaldehydes inwater High yields diastereoselectivities and ee values havebeen observedThe versatility of this resinwas also confirmedby selenenylation of aldehydes Both proline and prolinamideresins gave high yields Recycling studies showed that theproline resin performs as better heterogeneous organocat-alyst as compared to the prolinamide resin [153] An aldolreaction catalyzed by proline functionalized silica gel wasinvestigated in continuous flow microreactors by reaction-progress kinetic analysis and nonlinear chromatography[154]

Though the research community advocates asymmetricsynthesis for industrial application organocatalysts havebeen seldom applied in industry due to insufficient efficiencyand the difficulties in catalyst separation and recycling[155ndash161] The concept of heterogenizing organocatalyst onsupports combines the advantages of both homogeneousorganocatalysis and heterogeneous recycling Though thismight seem simple and present opportunities in indus-trial chemical processes the research in heterogeneousorganocatalysis demands a multidisciplinary approach byidentifying catalytic activity upon bonding organocatalystcovalently to the support understanding noncovalent inter-action as structure-reactivity and conformation decidingfactor taking into consideration the characteristic propertiesof the supports confinement effects if any and so forthSome recent examples will be described on the applicationsof supported proline as organocatalysts for their preindus-trialization study The latter half of this review in generalirons out the detailed discussion on key trendswith examplesscope challenges and ldquogreenrdquo applications of heterogeneousorganocatalysts

72 Other Amino Acids Barbas and coworkers found theproteinogenic amino acid tryptophan (Figure 4) to be anexcellent organocatalyst for the Mannich reaction of hydrox-yacetone with a variety of imines performed in DMF leadingthe desired anti-amino alcohols in excellent diastereoselec-tivities (up to gt19 1) and enantioselectivities (90ndash98 ee)Similarly t-butyl protected threonine catalyzed the aldolreaction of hydroxyacetone and various aldehydes in NMP togive the corresponding syn-aldol adducts in high yields andgood to excellent enantio- and diastereoselectivities [162]Zhao et al reported [163] the development of an aminoacid based small molecule capable of promoting asymmetricmonosilylation of meso-12-diols Furthermore the catalystcan be recycled with equal efficiency Three-componentreaction involving condensation of aldehyde 13-carbonyl

10 Journal of Catalysts

NH

OH

OH

O

O NHPh

O PhH

H

ON

NH

H

O OH

CO2BnCO2Bn

NO2

R1 R2

Scheme 5

NH

OH

O

H2N

Figure 4 L-Tryptophan

compound and (thio)urea is known as Biginelli reactionVarious organocatalysts such as tartaric acid oxalic acidcitric acid and lactic acid were found effective in producingBiginelli products [164ndash172]

Because of the ldquoprivilegedrdquo green nature of this fieldit has become an obligation for scientific community andacademic institutions to be mindful and teach this branchof catalysis to students and also keep it as a driving force inthe generation and dissemination of knowledge in pursuitof efficient synthetic methodologies and processes usingorganocatalysts The synthesis of new chiral building blocksor complex molecular structures involving organocatalyticstep(s) is being reported almost every day in scientificliterature As it is not possible here to discuss all the catalystsindividually in detail the author decides to present salientdevelopments in organocatalysis and allied research areas

Synthesis of prochiral cyclohexanones by amine cat-alyzed self-Diels-Alder reactions of 120572120573-unsaturated ketonesin water brought coupled the concept of green chemistry

with catalysis Useful asymmetric heterodomino reactionsfor the highly diastereoselective synthesis of symmetri-cal and nonsymmetrical synthons of benzoannelated cen-tropolyquinanes were reported [173 174]

In recent years trials are being made by using aminoacids especially L-proline to catalyze essential transforma-tions in the fine chemical and pharmaceutical industriesTheinterest in this field has thus increased spectacularly in the lastfew years However organocatalytic methods often requirecatalyst loadings as high as 30mol for the achievement ofhigh conversions in reasonable reaction times [175] Somecritics suggest that low turnover numbers might limit thepotential uses of organocatalysis for industrial applicationsProcess development and scale-up are being tested for severalorganocatalytic reactions confirming organocatalysis as avaluable tool for industrial scale solutions Scientists arereporting novel organocatalytic systems in various reputedinternational research journals and those catalysts exhibitvarious valuable functions derived from a variety of struc-tural ionicelectronic and chemical properties Broad varietyof efficient syntheses will contribute to an increasing numberof organocatalytic large scale reactions in the future Theorganocatalysts shall be used in various fields especially inasymmetric organic synthesis

73 Amine and Chiral Vicinal Diamines Proline and pyrro-lidine derivatives commonly known as Hayashi-Joslashrgensencatalysts in the form of ferrocenyl pyrrolidine are appliedas organocatalyst wherein the ferrocene moiety controls theconformational space and a simple alkyl group effectivelycovers a face of the derived enamine (Figure 5) [180]

Journal of Catalysts 11

R

RNR

REthanol rt

N

O

H

N

R R

+

10mol catalyst

R1

R1

R1R2

R3H2N

middotTfOH

Scheme 6

H NH

O

R

trans H N

O

H

RCis

Reactive conformation

Si

O

H

R

H

Ph

O

Ph

HO

SiCl3 Cl3

Scheme 7

Sulzer-Mosse and Alexakis reported chiral amines cat-alyzing asymmetric conjugate addition to nitroolefins andvinyl sulfones via enamine activation [181]

A bifunctional H-bond directing aminocatalytic systemis found to achieve high stereo- and regiocontrol overdienamine mediated hetero-Diels-Alder reaction [183]

Though amine catalysis is constructing a wide varietyof chiral scaffolds in asymmetric synthesis organocatalysiswith amines for nonasymmetric transformations is alsodeveloping very fast [184 185] The [2+2] cycloaddition ofenals with nitroalkenes is catalyzed by a chiral secondaryamine in the presence of an achiral thiourea for the enantio-and diastereoselective synthesis of highly functionalizedcyclobutanes Mechanistically two consecutiveMichael reac-tions proceed through an unprecedented combination ofdienamineiminium activation mode [186] The reactionengineering of dienamine catalysis for single-step synthesesof highly functionalized molecules such as natural productsor bioactive compounds is reviewed in literature [187]

Chin and coworkers have recently reported some pre-liminary theoretical and experimental studies for convertinga parent diamine into other chiral vicinal diamines Thesediamines can be handy as ligands for chiral catalysts or theycanmake chiral heterocyclic rings and betalactams [188ndash190]

There are some CndashC bonds forming reactions catalyzed bysuch diamine organocatalysts (Scheme 6) [191]

74 Amides Recently the synthesis of multifunctional or-ganocatalysts easily obtained by the condensation of (S)-proline with 2-aminopyridine 26-diaminopyridine or 2-aminoimidazole is reported These chiral prolinamides pro-moted the aldol condensation between cyclohexanone anddifferent aromatic aldehydes (up to 98ee) and also catalyzedDiels-Alder and Michael reactions [192 193]

Rationally designed pyrazole amides function as Michaeldonors in urea catalyzed asymmetric Michael reactions withexcellent chemical and optical yields [194]

A structure-activity relationship with regard to for-mamides as organocatalysts is exploredThis study highlightsthat the cis-conformation of secondary formamides is thereactive conformation in the allylation of aldehydes withallyltrichlorosilane (Scheme 7) [195]

75 Imidazolidinones A certain class of imidazolidinonecompounds (also called MacMillan imidazolidinone organ-ocatalysts) function as catalysts for many asymmetric organictransformations such as asymmetric Diels-Alder reactions

12 Journal of Catalysts

O

N

O

H

O

Up to 97 ee

OHH

N

NO

H20 mol catalyst

CHCl3 minus30∘C

C2H5O OC2H5

R1

R1

R2

R2

+

middotCF3CO2H

Scheme 8 Ouellet et al [202]

R

R

N

One favoured conformer

High enantioselectivity

R = alkyl

Fe

Figure 5

The original such compound was derived from the chi-ral biomolecule phenylalanine [196 197] The first highlyenantioselective organocatalytic Diels-Alder reaction usinga chiral organocatalyst was reported in MacMillanrsquos pio-neering work where the activated iminium ion formedthrough condensation of the imidazolidinone and an 120572120573-unsaturated aldehyde reacted with various dienes to give[4+2] cycloadducts in excellent yields and enantioselectivi-ties Ahrendt et al reportedmany other asymmetric reactionssuch as the 13-dipolar cycloadditions Friedel-Crafts alky-lations 120572-chlorinations 120572-fluorinations and intramolecularMichael reactions usingMacMillanrsquos organocatalysts [96 150198ndash201]

Ouellet et al also reported the combination of imida-zolidinone organocatalyst and Hantzsch ester to facilitatethe first enantioselective organocatalytic hydride reductionof 120572120573-unsaturated aldehydes (Scheme 8) [202 203] Thisimitated naturersquos stereoselective enzymatic transfer hydro-genation with NADH cofactor

Noncovalent interaction is a structure-reactivity andconformation deciding factor which requires immediateattention for understanding organocatalysis [204] Of specialinterest would be the identifying and understanding of othernoncovalent interactions such as charge transfer [205] pndashp stacking immobilization [206] and adsorption or entrap-ment of organocatalysts in nanomaterials [207]

Homogeneous and HeterogenizedMacMillanrsquos OrganocatalystAn asymmetric Diels-Alder reaction was catalyzed with highefficiency and recyclability by a soluble ldquoself-supportedrdquochiral organosilica polymer with embedded imidazolidinonecatalytic moieties [208]

76 Chiral Phosphoric Acids BINOL derived phosphoricacids catalyze nucleophilic addition reactions to imine sub-strates A direct Pictet-Spengler reaction was reported usinga geminally disubstituted tryptamine organocatalyst to formisoquinolines in excellent yield and enantiomeric excess[209] Phosphoric acid catalyzing the reduction of an iminewith a Hantzsch ester in good enantiomeric excess was firstlyreported by Rueping et al Hoffmann et al reported animprovement to this methodology [210 211]

Storer research group reported a one-pot reductive ami-nation of a range of methyl ketones and aryl amines [212]Reductive amination of 2-butanone over silylated phosphoricacid MacMillan TiPSY catalyst was obtained with goodenantiomeric excess

Zhou and List published on the use of chiral Broslashnstedacid (R)-TRIP for highly enantioselective synthesis of phar-maceutically relevant 3-substituted cyclohexylamines from26-diketones wherein the achiral amine substrate acceleratesthe cascade reaction before getting incorporated into the finalproduct (Scheme 9) [213]

Rowland et al reported VAPOL derived phosphoric acidcatalyzed addition of sulfonamides to BOC protected arylimines and protected aminals in excellent enantioselectivities[214]

The (R)-TRIP catalyzed the aza-Diels-Alder reaction ofaldimines with Danishefskyrsquos diene to yield piperidinonederivatives with high enantioselectivity Addition of aceticacid was found to improve both reactivity and enantiose-lectivity [215] Six chemical bonds five stereogenic centersand three cycles were formed in one-pot four-componentUgitype reaction catalyzed by a chiral BINOLderived phosphoricacid [216] BINAP is one of the earliy commercially appliedligands in industrial catalysis [217] Amicroporous recyclableheterogeneous catalyst offering excellent enantioselectivitywas made from a 111015840-binaphthalene-221015840-diol (binol) derivedphosphoric acid chloride and was found as active as thecorresponding homogeneous catalyst [218]

Journal of Catalysts 13

O

O

Ph

OEt HH

Ph

HN

OEt

i-Pr

i-Pr

i-Pri-Pr

i-Pr

i-Pr

O

OP O

OH

EtO2C CO2Et

CyclohexaneMS 5 A 50∘C

NH2

(R)-TRIP (10mol)

82 dr = 24 1 er = 98 21 22

Scheme 9 Zhou and List [213]

NO

N NHH N

HO

S

N

H R

BocO-PrTBS-O

Pr-O

HN

Boc

5mol catalyst+

t-Bu

t-Bu t-Bu

(2) TFA 2min(1) Toluene minus30∘C 48hr

86ndash98 ee

Scheme 10

HO OH

O O

Figure 6

77 Chiral Diols Huang et al reported on use of TADDOLs(Figure 6) as Broslashnsted acid organocatalysts in highly stereos-elective hetero-Diels-Alder reactions [219]

The 120572-amination of carbonyl compounds has also beenaccomplished by using the 1-naphthyl TADDOL derivative asa Broslashnsted acid organocatalyst [220] McDougal and Schausreported asymmetric Morita-Baylis-Hillman reaction that

is the addition of cyclohexenone to different aldehydescatalyzed by octahydro-BINOL derived Broslashnsted acid [221]

78 JacobsenThioureas ProfessorsVachal and Jacobsen iden-tified chiral thioureas (Figure 7) as versatile and effectiveorganocatalysts 1mol of the thiourea was reported to havecatalytic activity in the hydrocyanation (Strecker reaction) ofboth aldimines and ketoimines with very high enantioselec-tivities [222]

Imine hydrophosphonylation particularly effective withelectron-withdrawing ester substituents on the phosphatetook place in the presence of 10mol of the catalyst [223]Mannich reactions of BOC protected imines have also beenreported (Scheme 10) [224] with excellent yields and enan-tioselectivities and show heterocyclic substrate tolerance

A variant of thiourea organocatalyst was found to catalyzethe cyanosilylation of ketones and aldehydes in high yieldsand enantiomeric excesses [225] Thiourea organocatalystwas put to use in the acyl-Pictet-Spengler reaction to formtetrahydro-120573-carbolines [226] The acyl-Mannich reactionproviding a route to enantioenriched heterocycles from

14 Journal of Catalysts

N N N

H H NO H

HO

O

O

O

t-Bu

t-Bu

t-Bu

Figure 7

aromatic starting materials and trichloroethyl chloroformate(TrocCl) is also catalyzed by the thiourea organocatalyst[227] Bifunctional thiourea-base catalyzed double-Michaeladdition of benzofuran-2-ones to dienones is reported forthe synthesis of optically enriched spirocyclic benzofuran-2-ones [228] In another interesting example benzoylthiourea-pyrrolidine catalyst was synthesized and used in the asym-metric Michael addition of ketones to nitroalkenes [229]

Primary amine-thioureas were improvised to catalyzedifficult Michael reactions synthesizing (S)-baclofen (R)-baclofen and (S)-phenibut [230]

79 Cinchona Alkaloids The cinchona alkaloids catalyzemany useful processes with high enantioselectivities Asym-metric phase transfer catalysis (PTC) presents a ldquogreenrdquoalternative to homogeneous synthetic organic chemistrymethodologies Cinchona alkaloids are synthetically mod-ified for their usage in asymmetric PTC O-Alkyl N-arylmethyl derivatives of cinchona alkaloid led highly enantiose-lective alkylation of glycine imines to generate 120572-amino acidderivatives And for the same reaction dimeric cinchonaalkaloid obtained 97ndash99 enantiomeric excess [231 232]Cinchona alkaloids deprotonate substrates with relativelyacidic protons forming a contact ion pair between the result-ing anion and protonated amineThis interaction generates achiral pool around the anion and facilitates enantioselectivereactions with electrophiles The control over the formationof quaternary asymmetric centers is essential to obtain highenantiomeric excesses The 120572-functionalization of ketones(Scheme 11) by the addition of TMSCN to the correspondingcyanohydrin in excellent yield and enantiomeric excess iscatalyzed by the (DHQD)

2AQN catalyst [233]

Increasingly remote stereocenters are being targeted inasymmetric aminocatalysis Organocatalytic allylic amina-tion presents an alternative to the conventional palladiumcatalyzed methodology Amination at the remote 120574-positionusing (DHQ)

2PYR forms highly functionalized amine com-

pounds [234]Bella and Joslashrgensenrsquos reported the first enantioselective

conjugate addition of 120573-diketones to both aromatic andaliphatic alkynones using (DHQ)

2PHAL catalyst [235] Cin-

chona based primary amine catalysis is found to offer high

efficiency and reliability in the asymmetric functionalizationof carbonyl compounds [236 237] Organocatalysts derivedfrom cinchona alkaloids function as Lewis base catalyst inthe cyclizations of allenoates with electron deficient olefinsand imines and emerged as important synthetic tool inthe preparation of biologically active and pharmaceuticallyinteresting cyclic compounds including natural products[238] Recently cinchona thioureas have been reported forthe first time as catalysts in the area of asymmetric oxi-dations [239] Cinchona and cinchonidine derived catalystsperform asymmetric direct aldol reaction of pyruvic aldehydedimethyl acetal with isatin derivatives [240] Likewise thereare various other examples reported where cinchona or itsvariants are used as organocatalysts for syntheses of variousbiologically important molecules [241ndash246]

710 Maruoka Phase Transfer Catalysts The chiral catalystforms a host-guest complex with the substrate and shuttlesbetween the standard organic solvent and a second phaseexample catalytic enantioselective enolate alkylation [72]As we know chiral quaternary ammonium catalysts can beuseful in asymmetric synthesis Kitamura et al reported C2-symmetric ammonium salts catalyzing monoalkylation ofglycine derived Schiff bases with alkyl halides to synthesize120572-alkyl-120572-amino acids under remarkably low catalyst loadings[247ndash249]

Utilizing the solubility of aqueous quaternary ammoniumsalts into organic solvents professor Maruoka developedspirotype chiral ammonium salt with two binaphthyl ringsas a novel chiral phase transfer catalyst Figure 8 depicts theorganocatalyst for direct asymmetric aldol reaction of 120573-hydroxy-120572-amino acid derivative

711 Oxazaborolidines Chiral oxazaborolidines (known asCBS oxazaborolidines after Corey Bakshi and Shibata)catalyze the reduction of prochiral ketones imines andoximes to produce chiral alcohols amines and amino alco-hols respectively in high yields and excellent enantiomericexcesses The chiral Lewis acid generated from o-tolyl-CBS-oxazaborolidine after protonation with trifluoromethanesul-fonimide is very useful in the enantioselective Diels-Alderreaction (Scheme 12) [250ndash256]

Journal of Catalysts 15

O NC OTMSN

OH

N

N

OH

N

OO

2 to 20mol catalyst

TMSCN CHCl3

OC2H5

OC2H5

OC2H5

OC2H5

H3CO

C6H5C6H5

OCH3

Scheme 11 Tian et al [233]

OO

O

OO

II

CH3CH3

CH3

H3C

H3C TIPSOTIPSO

H

H

H

PhPh

NB

minus

+

+

(CF3SO2)2N

20mol catalyst

16hoursDichloromethane minus78∘C

Scheme 12 See [250ndash256]

712 Shi Epoxidation Catalyst Tu et al reported a fructosederived ketone in efficient asymmetric epoxidation of trans-olefins (Scheme 13) [257] Epoxidation catalyst is able toepoxidize trans-alkenes and certain cis-alkenes with good toexcellent yields and selectivities [258 259] Marigo et alrsquosgroup reported an asymmetric organocatalytic epoxidationof 120572 120573-unsaturated aldehydes with environmentally friendlyoxidant hydrogen peroxide [260]

713 N-Heterocyclic Carbene (NHC) as Organocatalysts

7131 Rovis Catalyst The conjugate addition of an aldehydeto an 120572120573-unsaturated compound (Stetter reaction) is apractical methodology for the construction of 14-dicarbonylcompounds bearing quaternary stereocenters Triazoliumsalt in the presence of a base functions as an N-heterocycliccarbene organocatalyst (Figure 9) in highly enantioselectiveintramolecular Stetter reactions [261 262]

7132 Bode Catalyst Bodersquos studies on NHCs (Figure 10)mainly involve catalytic generation of reactive speciessuch as enolates homoenolates and activated carboxylates

N-Mesityl substituent on an imidazolium or triazoliumNHCprecursor generates highly enantioselective annulations fromsimple starting materials under mild reaction conditions[263 264] In an interesting example the catalysts facilitatehighly enantioselective cyclopentene forming annulations ofsimple enals and activated enones [265] Redox esterificationsand amidations of 120572-functionalized aldehydes using achiralcatalyst are also reported [266] Uniting unique activationmodes of N-heterocyclic carbene (NHC) catalysts with theconcept of domino reactions a new fast-growing field cameinto the spotlight in last couple of years or so [267ndash269]

Domino Michaelaldol reaction between 2-mercapto-quinoline-3-carbaldehydes and enals was catalyzed by di-phenylprolinol silyl ether producing 2H-thiopyrano[23-b]-quinolines in excellent yields and enantioselectivities [270]Zhao et al reported studies on ldquocooperative NHC andrutheniun redox catalysisrdquo in the oxidative esterificationof aldehydes [271] Blanc et al reported NHC mediatedorganocatalytic one-pot allylstannation to generate syn-diols[272] With enals as starting aldehydes elegant cascadeprocesses have been developed using oxidative carbene catal-ysis [273ndash276] Over the last few years there are examplesreported in literature where various organocatalysts rally

16 Journal of Catalysts

O

Oxone

OO

O

O

OO

R1 R1

R3

R3

R2 R2H2OCH3CN

Scheme 13

F3C

N+

F3C

Brminus

CF3

CF3

Figure 8 See [176]

N

O

N

N

F

F

F

F

F

+BF4minus

Figure 9

domino reactions and attract their application in organicprocesses in industries [174 175 180 181 183]

Apart from the aforementioned organocatalysts thereare other organic systems which upon appropriate acti-vation function as catalysts in useful asymmetric synthe-ses [155ndash157] 12-Dicarbonyl compounds because of theiradjacent multiple reactive centers upon activation act asefficient pronucleophiles in asymmetric organocatalyzed

N

O

NN+

Clminus

Figure 10

sequential or domino transformations including CndashC or CndashN bond formation [277] Cyclopropenone catalyzed con-version of aldoximes and primary amides into nitriles ina one-pot mild reaction widens the scope of the utiliza-tion of cyclopropenones in organic synthesis [278] Thefirst asymmetric organocatalytic synthesis by phosphinecatalyzed [3+2] cycloaddition of allenoates onto fullereneis reported to yield enantiomerically pure carbocyclicfullerene derivatives under mild conditions [279] A new[3+2] cycloadditioncycloreversion strategy for organocat-alytic and thermally allowed carbonyl-olefin metathesis isreported [280] Recently a strong evidence for halogenbond based organocatalysis is reported for the reactionof 1-chloroisochroman with ketene silyl acetals [281] Acidcatalyzed asymmetric acetalizations of aldehydes are alsodescribed [282] beta-Isocupreidine catalyzed the enantios-elective Morita-Baylis-Hillman reaction of maleimides withisatin derivatives to form 3-substituted 3-hydroxyoxindolederivatives [283 284]

Recent advances in asymmetric catalysis resulted in uti-lizing the less discussed electrophilic properties of iminiumtype intermediates in complex annulations of indoles [285286] and also pyridines [287 288] Shibatomi and Narayamadiscussed the catalytic enantioselective 120572-chlorination of car-bonyl compounds and stereospecific substitution reactions ofthe resulting optically active alkyl chlorides [289]

Though there is no relation between the developmentof two different fields of organocatalysis and gold catalysis

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

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[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

[17] J R Anderson and K C Pratt Introduction To Characterisationand Testing of Catalysts Academic Press Sydney Australia1985

[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

Journal of Catalysts 7

O

O

O

O

OOH

100

N

H

3mol L-proline

DMF 20∘C 20h

CO2H

Scheme 1 Hajos and Parrish [70]

O

O

OOO

O

O

30mol catalyst

30 H2O2 (3 equivalent)

CH3CNndashK2CO3

R1R3

R2

R1R3

R2

Scheme 2 Shu and Shi [71]

Catalytic enantioselective enolate alkylation(Scheme 3) occurs

Type-IV molecular-cavity-accelerated asymmetrictransformations occur in which the catalyst mayselect from competing substrates depending on sizeand structure criteria (Scheme 4)

6 Discovery and the History ofOrganocatalysis

Liebigrsquos synthesis of oxamide from dicyan and water is thefirst organocatalytic reaction reported [74] Acetaldehydewasfurther identified to behave as the then-named ldquofermentrdquonow called as enzyme Dakin in 1909 demonstrated that ina Knoevenagel type condensation between aldehydes andcarboxylic acids or esters with active methylene groups theamine catalysts could be mediated by amino acids [75]Langenbeck is remembered for developing enamine typereactions and the application of simple amino acids andsmall oligopeptides as catalysts [76ndash78] Natural products inparticular strychnine brucine and cinchona alkaloids andamino acids (including short oligopeptides) were amongthe first organic catalysts tested [79 80] Though the fieldof small-molecule catalysts seems very simple there are

evidences that prove their pivotal role in synthesis of buildingblocks for life L-Alanine andL-isovaline capable of catalyzingcertain CndashC bond formation reactions had been found onmeteorites [81]

An asymmetric transformation with an organic moleculewas published in 1912 by Bredig and Fiske [82] Pracejusapplied cinchona alkaloids in the asymmetric conversionof ketenes to (S)-methyl hydratropate [83 84] An initialresearch byYamadaampOtaniwas important too [85]The sev-enties brought anothermilestone Hajos and Parrish reporteda L-proline catalyzed Robinson annulation in excellent enan-tioselectivities [70 86 87] Eder et al reported organocat-alytic aldol reactions in good enantioselectivities [88] Tosummarize in 1970s Hajos and Parrish and independentlyEder Sauer and Wiechert published a series of papers andpatents involving such organocatalytic transformations Theasymmetric synthesis of enediones useful building blocksin natural product total syntheses was achieved (S)-Prolineinduced the formation of (S)-enediones

Two mechanisms [89] were proposed (1) involving theformation of a carbinolamine intermediate followed by thedisplacement of the proline moiety by nucleophilic attackof the enol from the side chain ketone (2) involving anenaminium intermediate acting as a nucleophile in the CndashCbond formation with concomitant NHsdot sdot sdotO hydrogen trans-fer Wynberg firstly published various 12 and 14 additionscatalyzed by cinchona bifunctional organocatalysis [90ndash92]

8 Journal of Catalysts

N

O

Ph

Ph

Ph

Ph

N

O

OO

O

81 96 eeO

O

O

O

H N

Chiral quaternary ammonium catalyst10mol catalyst

CH2Cl2BrH2C

Ot-Bu

Ot-Buminus78

∘C 24h

+

Brminus

CsOHmiddotH2O

Scheme 3 Corey et al [72]

O

BOCHN BOCHN

OO OH

Nu

OH

(2) Nu

(1) Polymer

HO

N

HN

HO

O

O

OH

NO2

NO2

+

Scheme 4 Sellergren et al [73]

All these research endeavours were not carefully looked intotill List et al reported in 2000 proline catalyzed aldol reactionin good enantiomeric excesses [93 94]

Asymmetric catalysis constitutes one of the most impor-tant subjects in synthetic organic chemistry Asymmetricsynthesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the application of such methodologies inchemical industry is rather limited due to the high cost ofchiral ligands and noble metals used in such transformationsMoreover the pharmaceutical entities and food industryproducts do not tolerate a contamination of even traces ofany such metals for that matter Synthesis of chiral drugshas a major financial impact in pharmaceutical industrieson a global scale Different enantiomers or diastereomers ofa molecule often have different biological activity Most ofthe drugs might be soon sold as single enantiomers in thecoming years There is a huge demand for organocatalystsleading to 100 yield 100 ee of the desired product Theneed from chemical industry especially pharmaceutical forreliable asymmetric transformations of molecular skeletonsis higher than ever Therefore asymmetric organocatalysisis in a process of attaining maturity into a very powerful

practical and broadly applicable methodological approach inthe catalytic asymmetric synthesis

7 Some Examples and Developments inCatalyst Structural Variants

Following are the famous examples of organocatalysts

71 Proline and Derivatives The proline catalyzed Robinsonannulation was one of the earliest examples of an enantios-elective reaction using an organic catalyst [85] This aminoacid contains both a nucleophilic secondary amino groupand a carboxylic acid moiety functioning as a Broslashnstedacid The availability of proline in both enantiomeric formsbrings advantages over enzymatic methods Arguably thefirst example of proline catalyzed asymmetric aldol reactionis reported by Hajos and Parrish [70 86 87] The Wieland-Miescher ketone is a useful synthetic building block forwhich a classical asymmetric procedure using (S)-prolinewas published forty years ago [88] It is quite significant thatthe first efficient organocatalyzed asymmetric reactions weredescribed by Hajos amp Parrish [86 87] and by Eder et al [88]

Journal of Catalysts 9

both teams from pharmaceutical companies (Hoffmann-la-Roche and Schering) The asymmetric synthesis of theWieland-Miescher ketone is also based on proline andanother early application was one of the transformations inthe total synthesis of erythromycin by Woodward et al [95]Proline is recognized as a versatile organocatalyst of thesetimes (Scheme 5)

In fact the renewal of proline catalyzed transformationsin early 2000 by D W C MacMillan Carlos F Barbas IIIand Benjamin List saw the renaissance of the concept and itwas the starting point of the word ldquoorganocatalysisrdquo ProfessorAhrendt group reported the first enantioselective organocat-alytic Diels-Alder reaction [96] Proline was identified asan effective organocatalyst for asymmetric aldol reaction[97] The catalytic asymmetric 120572-alkylation of aldehydeswas reported by Vignola and List [98] This transformationhad been accomplished with the help of covalently attachedauxiliaries 120572-Methyl L-proline exhibits higher enantioselec-tivities and improved reaction rates when compared to L-proline In recent years proline especially L-proline hasbeen used to catalyze essential transformations used in thefine chemical and pharmaceutical industries such as thedirect asymmetric aldol reactions [99ndash107] Diels-Alder reac-tions Michael reactions [108ndash115] Mannich reaction [116ndash122] Multicomponent reactions [123 124] and 120572-amination[125] 120572-aminoxylation [126ndash128] 120572-oxyaldehyde dimer-ization [100] 120572-functionalization of carbonyl compounds[129] and 120572-alkylation of aldehydes [130] Organocat-alytic cyclopropanation reactions were typically performedusing catalyst-bound ylides However Kunz and MacMil-lan demonstrated that activation of olefin substrates usingcatalytic (S)-(minus)-indoline-2-carboxylic acid is a viable routefor the formation of highly enantioenriched cyclopropanes[131]

Prof K A Joslashrgensen has made an importantbreakthrough in asymmetric synthesis by developing (R)-and (S)-120572120572-bis[35-bis(trifluoromethyl)phenyl]-2-pyrroli-dinemethanol trimethylsilyl ether as excellent chiral organ-ocatalysts in the direct organocatalytic 120572-functionaliza-tion of aldehydes Diarylprolinol silyl ether reagents werefound to catalyze CndashC CndashN CndashO CndashS and CndashHal bondforming reactions [132ndash138] Cascade or domino reactionsswiftly construct complex biologically important compoundsand minimize waste and also the laboratory operations [139]Endersrsquo group developed proline derived organocatalyst fora chemo- diastereo- and enantioselective three-componentdomino reaction to yield tetrasubstituted cyclohexenecarbaldehydes [140] The four stereogenic centers aregenerated in three consecutive CndashC bond formations thatis MichaelMichaelaldol condensation with high diastereo-and complete enantiocontrolThe synthesis of polyfunctionalcyclohexene building blocks involving proline catalytic stepsis reported in this domino reaction

Though this segment of our review is dedicated to prolineas an important class of organocatalysts it would also be agood place to acknowledge the research contributions fromprofessor Ahrendt et al to the field of organocatalysis [96 99100 103 127 131 141ndash150]

Heterogenized Proline An explosion of research articles inthe area of homogeneous organocatalysis occurredwithin thelast decade or so In addition to the initial proline catalyzedreactions the word ldquoorganocatalysisrdquo covers nowadays manyotherwell-knownorganocatalysts and organic reactions Pro-line immobilized onto some sort of inorganic support pavesthe way towards heterogenization of other organocatalysts[151ndash153] A simple and efficient synthesis of polystyrene-supported proline and prolinamide is reported Polystyrene-supported proline catalyzes the asymmetric aldol reactionbetween cyclohexanone and substituted benzaldehydes inwater High yields diastereoselectivities and ee values havebeen observedThe versatility of this resinwas also confirmedby selenenylation of aldehydes Both proline and prolinamideresins gave high yields Recycling studies showed that theproline resin performs as better heterogeneous organocat-alyst as compared to the prolinamide resin [153] An aldolreaction catalyzed by proline functionalized silica gel wasinvestigated in continuous flow microreactors by reaction-progress kinetic analysis and nonlinear chromatography[154]

Though the research community advocates asymmetricsynthesis for industrial application organocatalysts havebeen seldom applied in industry due to insufficient efficiencyand the difficulties in catalyst separation and recycling[155ndash161] The concept of heterogenizing organocatalyst onsupports combines the advantages of both homogeneousorganocatalysis and heterogeneous recycling Though thismight seem simple and present opportunities in indus-trial chemical processes the research in heterogeneousorganocatalysis demands a multidisciplinary approach byidentifying catalytic activity upon bonding organocatalystcovalently to the support understanding noncovalent inter-action as structure-reactivity and conformation decidingfactor taking into consideration the characteristic propertiesof the supports confinement effects if any and so forthSome recent examples will be described on the applicationsof supported proline as organocatalysts for their preindus-trialization study The latter half of this review in generalirons out the detailed discussion on key trendswith examplesscope challenges and ldquogreenrdquo applications of heterogeneousorganocatalysts

72 Other Amino Acids Barbas and coworkers found theproteinogenic amino acid tryptophan (Figure 4) to be anexcellent organocatalyst for the Mannich reaction of hydrox-yacetone with a variety of imines performed in DMF leadingthe desired anti-amino alcohols in excellent diastereoselec-tivities (up to gt19 1) and enantioselectivities (90ndash98 ee)Similarly t-butyl protected threonine catalyzed the aldolreaction of hydroxyacetone and various aldehydes in NMP togive the corresponding syn-aldol adducts in high yields andgood to excellent enantio- and diastereoselectivities [162]Zhao et al reported [163] the development of an aminoacid based small molecule capable of promoting asymmetricmonosilylation of meso-12-diols Furthermore the catalystcan be recycled with equal efficiency Three-componentreaction involving condensation of aldehyde 13-carbonyl

10 Journal of Catalysts

NH

OH

OH

O

O NHPh

O PhH

H

ON

NH

H

O OH

CO2BnCO2Bn

NO2

R1 R2

Scheme 5

NH

OH

O

H2N

Figure 4 L-Tryptophan

compound and (thio)urea is known as Biginelli reactionVarious organocatalysts such as tartaric acid oxalic acidcitric acid and lactic acid were found effective in producingBiginelli products [164ndash172]

Because of the ldquoprivilegedrdquo green nature of this fieldit has become an obligation for scientific community andacademic institutions to be mindful and teach this branchof catalysis to students and also keep it as a driving force inthe generation and dissemination of knowledge in pursuitof efficient synthetic methodologies and processes usingorganocatalysts The synthesis of new chiral building blocksor complex molecular structures involving organocatalyticstep(s) is being reported almost every day in scientificliterature As it is not possible here to discuss all the catalystsindividually in detail the author decides to present salientdevelopments in organocatalysis and allied research areas

Synthesis of prochiral cyclohexanones by amine cat-alyzed self-Diels-Alder reactions of 120572120573-unsaturated ketonesin water brought coupled the concept of green chemistry

with catalysis Useful asymmetric heterodomino reactionsfor the highly diastereoselective synthesis of symmetri-cal and nonsymmetrical synthons of benzoannelated cen-tropolyquinanes were reported [173 174]

In recent years trials are being made by using aminoacids especially L-proline to catalyze essential transforma-tions in the fine chemical and pharmaceutical industriesTheinterest in this field has thus increased spectacularly in the lastfew years However organocatalytic methods often requirecatalyst loadings as high as 30mol for the achievement ofhigh conversions in reasonable reaction times [175] Somecritics suggest that low turnover numbers might limit thepotential uses of organocatalysis for industrial applicationsProcess development and scale-up are being tested for severalorganocatalytic reactions confirming organocatalysis as avaluable tool for industrial scale solutions Scientists arereporting novel organocatalytic systems in various reputedinternational research journals and those catalysts exhibitvarious valuable functions derived from a variety of struc-tural ionicelectronic and chemical properties Broad varietyof efficient syntheses will contribute to an increasing numberof organocatalytic large scale reactions in the future Theorganocatalysts shall be used in various fields especially inasymmetric organic synthesis

73 Amine and Chiral Vicinal Diamines Proline and pyrro-lidine derivatives commonly known as Hayashi-Joslashrgensencatalysts in the form of ferrocenyl pyrrolidine are appliedas organocatalyst wherein the ferrocene moiety controls theconformational space and a simple alkyl group effectivelycovers a face of the derived enamine (Figure 5) [180]

Journal of Catalysts 11

R

RNR

REthanol rt

N

O

H

N

R R

+

10mol catalyst

R1

R1

R1R2

R3H2N

middotTfOH

Scheme 6

H NH

O

R

trans H N

O

H

RCis

Reactive conformation

Si

O

H

R

H

Ph

O

Ph

HO

SiCl3 Cl3

Scheme 7

Sulzer-Mosse and Alexakis reported chiral amines cat-alyzing asymmetric conjugate addition to nitroolefins andvinyl sulfones via enamine activation [181]

A bifunctional H-bond directing aminocatalytic systemis found to achieve high stereo- and regiocontrol overdienamine mediated hetero-Diels-Alder reaction [183]

Though amine catalysis is constructing a wide varietyof chiral scaffolds in asymmetric synthesis organocatalysiswith amines for nonasymmetric transformations is alsodeveloping very fast [184 185] The [2+2] cycloaddition ofenals with nitroalkenes is catalyzed by a chiral secondaryamine in the presence of an achiral thiourea for the enantio-and diastereoselective synthesis of highly functionalizedcyclobutanes Mechanistically two consecutiveMichael reac-tions proceed through an unprecedented combination ofdienamineiminium activation mode [186] The reactionengineering of dienamine catalysis for single-step synthesesof highly functionalized molecules such as natural productsor bioactive compounds is reviewed in literature [187]

Chin and coworkers have recently reported some pre-liminary theoretical and experimental studies for convertinga parent diamine into other chiral vicinal diamines Thesediamines can be handy as ligands for chiral catalysts or theycanmake chiral heterocyclic rings and betalactams [188ndash190]

There are some CndashC bonds forming reactions catalyzed bysuch diamine organocatalysts (Scheme 6) [191]

74 Amides Recently the synthesis of multifunctional or-ganocatalysts easily obtained by the condensation of (S)-proline with 2-aminopyridine 26-diaminopyridine or 2-aminoimidazole is reported These chiral prolinamides pro-moted the aldol condensation between cyclohexanone anddifferent aromatic aldehydes (up to 98ee) and also catalyzedDiels-Alder and Michael reactions [192 193]

Rationally designed pyrazole amides function as Michaeldonors in urea catalyzed asymmetric Michael reactions withexcellent chemical and optical yields [194]

A structure-activity relationship with regard to for-mamides as organocatalysts is exploredThis study highlightsthat the cis-conformation of secondary formamides is thereactive conformation in the allylation of aldehydes withallyltrichlorosilane (Scheme 7) [195]

75 Imidazolidinones A certain class of imidazolidinonecompounds (also called MacMillan imidazolidinone organ-ocatalysts) function as catalysts for many asymmetric organictransformations such as asymmetric Diels-Alder reactions

12 Journal of Catalysts

O

N

O

H

O

Up to 97 ee

OHH

N

NO

H20 mol catalyst

CHCl3 minus30∘C

C2H5O OC2H5

R1

R1

R2

R2

+

middotCF3CO2H

Scheme 8 Ouellet et al [202]

R

R

N

One favoured conformer

High enantioselectivity

R = alkyl

Fe

Figure 5

The original such compound was derived from the chi-ral biomolecule phenylalanine [196 197] The first highlyenantioselective organocatalytic Diels-Alder reaction usinga chiral organocatalyst was reported in MacMillanrsquos pio-neering work where the activated iminium ion formedthrough condensation of the imidazolidinone and an 120572120573-unsaturated aldehyde reacted with various dienes to give[4+2] cycloadducts in excellent yields and enantioselectivi-ties Ahrendt et al reportedmany other asymmetric reactionssuch as the 13-dipolar cycloadditions Friedel-Crafts alky-lations 120572-chlorinations 120572-fluorinations and intramolecularMichael reactions usingMacMillanrsquos organocatalysts [96 150198ndash201]

Ouellet et al also reported the combination of imida-zolidinone organocatalyst and Hantzsch ester to facilitatethe first enantioselective organocatalytic hydride reductionof 120572120573-unsaturated aldehydes (Scheme 8) [202 203] Thisimitated naturersquos stereoselective enzymatic transfer hydro-genation with NADH cofactor

Noncovalent interaction is a structure-reactivity andconformation deciding factor which requires immediateattention for understanding organocatalysis [204] Of specialinterest would be the identifying and understanding of othernoncovalent interactions such as charge transfer [205] pndashp stacking immobilization [206] and adsorption or entrap-ment of organocatalysts in nanomaterials [207]

Homogeneous and HeterogenizedMacMillanrsquos OrganocatalystAn asymmetric Diels-Alder reaction was catalyzed with highefficiency and recyclability by a soluble ldquoself-supportedrdquochiral organosilica polymer with embedded imidazolidinonecatalytic moieties [208]

76 Chiral Phosphoric Acids BINOL derived phosphoricacids catalyze nucleophilic addition reactions to imine sub-strates A direct Pictet-Spengler reaction was reported usinga geminally disubstituted tryptamine organocatalyst to formisoquinolines in excellent yield and enantiomeric excess[209] Phosphoric acid catalyzing the reduction of an iminewith a Hantzsch ester in good enantiomeric excess was firstlyreported by Rueping et al Hoffmann et al reported animprovement to this methodology [210 211]

Storer research group reported a one-pot reductive ami-nation of a range of methyl ketones and aryl amines [212]Reductive amination of 2-butanone over silylated phosphoricacid MacMillan TiPSY catalyst was obtained with goodenantiomeric excess

Zhou and List published on the use of chiral Broslashnstedacid (R)-TRIP for highly enantioselective synthesis of phar-maceutically relevant 3-substituted cyclohexylamines from26-diketones wherein the achiral amine substrate acceleratesthe cascade reaction before getting incorporated into the finalproduct (Scheme 9) [213]

Rowland et al reported VAPOL derived phosphoric acidcatalyzed addition of sulfonamides to BOC protected arylimines and protected aminals in excellent enantioselectivities[214]

The (R)-TRIP catalyzed the aza-Diels-Alder reaction ofaldimines with Danishefskyrsquos diene to yield piperidinonederivatives with high enantioselectivity Addition of aceticacid was found to improve both reactivity and enantiose-lectivity [215] Six chemical bonds five stereogenic centersand three cycles were formed in one-pot four-componentUgitype reaction catalyzed by a chiral BINOLderived phosphoricacid [216] BINAP is one of the earliy commercially appliedligands in industrial catalysis [217] Amicroporous recyclableheterogeneous catalyst offering excellent enantioselectivitywas made from a 111015840-binaphthalene-221015840-diol (binol) derivedphosphoric acid chloride and was found as active as thecorresponding homogeneous catalyst [218]

Journal of Catalysts 13

O

O

Ph

OEt HH

Ph

HN

OEt

i-Pr

i-Pr

i-Pri-Pr

i-Pr

i-Pr

O

OP O

OH

EtO2C CO2Et

CyclohexaneMS 5 A 50∘C

NH2

(R)-TRIP (10mol)

82 dr = 24 1 er = 98 21 22

Scheme 9 Zhou and List [213]

NO

N NHH N

HO

S

N

H R

BocO-PrTBS-O

Pr-O

HN

Boc

5mol catalyst+

t-Bu

t-Bu t-Bu

(2) TFA 2min(1) Toluene minus30∘C 48hr

86ndash98 ee

Scheme 10

HO OH

O O

Figure 6

77 Chiral Diols Huang et al reported on use of TADDOLs(Figure 6) as Broslashnsted acid organocatalysts in highly stereos-elective hetero-Diels-Alder reactions [219]

The 120572-amination of carbonyl compounds has also beenaccomplished by using the 1-naphthyl TADDOL derivative asa Broslashnsted acid organocatalyst [220] McDougal and Schausreported asymmetric Morita-Baylis-Hillman reaction that

is the addition of cyclohexenone to different aldehydescatalyzed by octahydro-BINOL derived Broslashnsted acid [221]

78 JacobsenThioureas ProfessorsVachal and Jacobsen iden-tified chiral thioureas (Figure 7) as versatile and effectiveorganocatalysts 1mol of the thiourea was reported to havecatalytic activity in the hydrocyanation (Strecker reaction) ofboth aldimines and ketoimines with very high enantioselec-tivities [222]

Imine hydrophosphonylation particularly effective withelectron-withdrawing ester substituents on the phosphatetook place in the presence of 10mol of the catalyst [223]Mannich reactions of BOC protected imines have also beenreported (Scheme 10) [224] with excellent yields and enan-tioselectivities and show heterocyclic substrate tolerance

A variant of thiourea organocatalyst was found to catalyzethe cyanosilylation of ketones and aldehydes in high yieldsand enantiomeric excesses [225] Thiourea organocatalystwas put to use in the acyl-Pictet-Spengler reaction to formtetrahydro-120573-carbolines [226] The acyl-Mannich reactionproviding a route to enantioenriched heterocycles from

14 Journal of Catalysts

N N N

H H NO H

HO

O

O

O

t-Bu

t-Bu

t-Bu

Figure 7

aromatic starting materials and trichloroethyl chloroformate(TrocCl) is also catalyzed by the thiourea organocatalyst[227] Bifunctional thiourea-base catalyzed double-Michaeladdition of benzofuran-2-ones to dienones is reported forthe synthesis of optically enriched spirocyclic benzofuran-2-ones [228] In another interesting example benzoylthiourea-pyrrolidine catalyst was synthesized and used in the asym-metric Michael addition of ketones to nitroalkenes [229]

Primary amine-thioureas were improvised to catalyzedifficult Michael reactions synthesizing (S)-baclofen (R)-baclofen and (S)-phenibut [230]

79 Cinchona Alkaloids The cinchona alkaloids catalyzemany useful processes with high enantioselectivities Asym-metric phase transfer catalysis (PTC) presents a ldquogreenrdquoalternative to homogeneous synthetic organic chemistrymethodologies Cinchona alkaloids are synthetically mod-ified for their usage in asymmetric PTC O-Alkyl N-arylmethyl derivatives of cinchona alkaloid led highly enantiose-lective alkylation of glycine imines to generate 120572-amino acidderivatives And for the same reaction dimeric cinchonaalkaloid obtained 97ndash99 enantiomeric excess [231 232]Cinchona alkaloids deprotonate substrates with relativelyacidic protons forming a contact ion pair between the result-ing anion and protonated amineThis interaction generates achiral pool around the anion and facilitates enantioselectivereactions with electrophiles The control over the formationof quaternary asymmetric centers is essential to obtain highenantiomeric excesses The 120572-functionalization of ketones(Scheme 11) by the addition of TMSCN to the correspondingcyanohydrin in excellent yield and enantiomeric excess iscatalyzed by the (DHQD)

2AQN catalyst [233]

Increasingly remote stereocenters are being targeted inasymmetric aminocatalysis Organocatalytic allylic amina-tion presents an alternative to the conventional palladiumcatalyzed methodology Amination at the remote 120574-positionusing (DHQ)

2PYR forms highly functionalized amine com-

pounds [234]Bella and Joslashrgensenrsquos reported the first enantioselective

conjugate addition of 120573-diketones to both aromatic andaliphatic alkynones using (DHQ)

2PHAL catalyst [235] Cin-

chona based primary amine catalysis is found to offer high

efficiency and reliability in the asymmetric functionalizationof carbonyl compounds [236 237] Organocatalysts derivedfrom cinchona alkaloids function as Lewis base catalyst inthe cyclizations of allenoates with electron deficient olefinsand imines and emerged as important synthetic tool inthe preparation of biologically active and pharmaceuticallyinteresting cyclic compounds including natural products[238] Recently cinchona thioureas have been reported forthe first time as catalysts in the area of asymmetric oxi-dations [239] Cinchona and cinchonidine derived catalystsperform asymmetric direct aldol reaction of pyruvic aldehydedimethyl acetal with isatin derivatives [240] Likewise thereare various other examples reported where cinchona or itsvariants are used as organocatalysts for syntheses of variousbiologically important molecules [241ndash246]

710 Maruoka Phase Transfer Catalysts The chiral catalystforms a host-guest complex with the substrate and shuttlesbetween the standard organic solvent and a second phaseexample catalytic enantioselective enolate alkylation [72]As we know chiral quaternary ammonium catalysts can beuseful in asymmetric synthesis Kitamura et al reported C2-symmetric ammonium salts catalyzing monoalkylation ofglycine derived Schiff bases with alkyl halides to synthesize120572-alkyl-120572-amino acids under remarkably low catalyst loadings[247ndash249]

Utilizing the solubility of aqueous quaternary ammoniumsalts into organic solvents professor Maruoka developedspirotype chiral ammonium salt with two binaphthyl ringsas a novel chiral phase transfer catalyst Figure 8 depicts theorganocatalyst for direct asymmetric aldol reaction of 120573-hydroxy-120572-amino acid derivative

711 Oxazaborolidines Chiral oxazaborolidines (known asCBS oxazaborolidines after Corey Bakshi and Shibata)catalyze the reduction of prochiral ketones imines andoximes to produce chiral alcohols amines and amino alco-hols respectively in high yields and excellent enantiomericexcesses The chiral Lewis acid generated from o-tolyl-CBS-oxazaborolidine after protonation with trifluoromethanesul-fonimide is very useful in the enantioselective Diels-Alderreaction (Scheme 12) [250ndash256]

Journal of Catalysts 15

O NC OTMSN

OH

N

N

OH

N

OO

2 to 20mol catalyst

TMSCN CHCl3

OC2H5

OC2H5

OC2H5

OC2H5

H3CO

C6H5C6H5

OCH3

Scheme 11 Tian et al [233]

OO

O

OO

II

CH3CH3

CH3

H3C

H3C TIPSOTIPSO

H

H

H

PhPh

NB

minus

+

+

(CF3SO2)2N

20mol catalyst

16hoursDichloromethane minus78∘C

Scheme 12 See [250ndash256]

712 Shi Epoxidation Catalyst Tu et al reported a fructosederived ketone in efficient asymmetric epoxidation of trans-olefins (Scheme 13) [257] Epoxidation catalyst is able toepoxidize trans-alkenes and certain cis-alkenes with good toexcellent yields and selectivities [258 259] Marigo et alrsquosgroup reported an asymmetric organocatalytic epoxidationof 120572 120573-unsaturated aldehydes with environmentally friendlyoxidant hydrogen peroxide [260]

713 N-Heterocyclic Carbene (NHC) as Organocatalysts

7131 Rovis Catalyst The conjugate addition of an aldehydeto an 120572120573-unsaturated compound (Stetter reaction) is apractical methodology for the construction of 14-dicarbonylcompounds bearing quaternary stereocenters Triazoliumsalt in the presence of a base functions as an N-heterocycliccarbene organocatalyst (Figure 9) in highly enantioselectiveintramolecular Stetter reactions [261 262]

7132 Bode Catalyst Bodersquos studies on NHCs (Figure 10)mainly involve catalytic generation of reactive speciessuch as enolates homoenolates and activated carboxylates

N-Mesityl substituent on an imidazolium or triazoliumNHCprecursor generates highly enantioselective annulations fromsimple starting materials under mild reaction conditions[263 264] In an interesting example the catalysts facilitatehighly enantioselective cyclopentene forming annulations ofsimple enals and activated enones [265] Redox esterificationsand amidations of 120572-functionalized aldehydes using achiralcatalyst are also reported [266] Uniting unique activationmodes of N-heterocyclic carbene (NHC) catalysts with theconcept of domino reactions a new fast-growing field cameinto the spotlight in last couple of years or so [267ndash269]

Domino Michaelaldol reaction between 2-mercapto-quinoline-3-carbaldehydes and enals was catalyzed by di-phenylprolinol silyl ether producing 2H-thiopyrano[23-b]-quinolines in excellent yields and enantioselectivities [270]Zhao et al reported studies on ldquocooperative NHC andrutheniun redox catalysisrdquo in the oxidative esterificationof aldehydes [271] Blanc et al reported NHC mediatedorganocatalytic one-pot allylstannation to generate syn-diols[272] With enals as starting aldehydes elegant cascadeprocesses have been developed using oxidative carbene catal-ysis [273ndash276] Over the last few years there are examplesreported in literature where various organocatalysts rally

16 Journal of Catalysts

O

Oxone

OO

O

O

OO

R1 R1

R3

R3

R2 R2H2OCH3CN

Scheme 13

F3C

N+

F3C

Brminus

CF3

CF3

Figure 8 See [176]

N

O

N

N

F

F

F

F

F

+BF4minus

Figure 9

domino reactions and attract their application in organicprocesses in industries [174 175 180 181 183]

Apart from the aforementioned organocatalysts thereare other organic systems which upon appropriate acti-vation function as catalysts in useful asymmetric synthe-ses [155ndash157] 12-Dicarbonyl compounds because of theiradjacent multiple reactive centers upon activation act asefficient pronucleophiles in asymmetric organocatalyzed

N

O

NN+

Clminus

Figure 10

sequential or domino transformations including CndashC or CndashN bond formation [277] Cyclopropenone catalyzed con-version of aldoximes and primary amides into nitriles ina one-pot mild reaction widens the scope of the utiliza-tion of cyclopropenones in organic synthesis [278] Thefirst asymmetric organocatalytic synthesis by phosphinecatalyzed [3+2] cycloaddition of allenoates onto fullereneis reported to yield enantiomerically pure carbocyclicfullerene derivatives under mild conditions [279] A new[3+2] cycloadditioncycloreversion strategy for organocat-alytic and thermally allowed carbonyl-olefin metathesis isreported [280] Recently a strong evidence for halogenbond based organocatalysis is reported for the reactionof 1-chloroisochroman with ketene silyl acetals [281] Acidcatalyzed asymmetric acetalizations of aldehydes are alsodescribed [282] beta-Isocupreidine catalyzed the enantios-elective Morita-Baylis-Hillman reaction of maleimides withisatin derivatives to form 3-substituted 3-hydroxyoxindolederivatives [283 284]

Recent advances in asymmetric catalysis resulted in uti-lizing the less discussed electrophilic properties of iminiumtype intermediates in complex annulations of indoles [285286] and also pyridines [287 288] Shibatomi and Narayamadiscussed the catalytic enantioselective 120572-chlorination of car-bonyl compounds and stereospecific substitution reactions ofthe resulting optically active alkyl chlorides [289]

Though there is no relation between the developmentof two different fields of organocatalysis and gold catalysis

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

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[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

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[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

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[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

8 Journal of Catalysts

N

O

Ph

Ph

Ph

Ph

N

O

OO

O

81 96 eeO

O

O

O

H N

Chiral quaternary ammonium catalyst10mol catalyst

CH2Cl2BrH2C

Ot-Bu

Ot-Buminus78

∘C 24h

+

Brminus

CsOHmiddotH2O

Scheme 3 Corey et al [72]

O

BOCHN BOCHN

OO OH

Nu

OH

(2) Nu

(1) Polymer

HO

N

HN

HO

O

O

OH

NO2

NO2

+

Scheme 4 Sellergren et al [73]

All these research endeavours were not carefully looked intotill List et al reported in 2000 proline catalyzed aldol reactionin good enantiomeric excesses [93 94]

Asymmetric catalysis constitutes one of the most impor-tant subjects in synthetic organic chemistry Asymmetricsynthesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the application of such methodologies inchemical industry is rather limited due to the high cost ofchiral ligands and noble metals used in such transformationsMoreover the pharmaceutical entities and food industryproducts do not tolerate a contamination of even traces ofany such metals for that matter Synthesis of chiral drugshas a major financial impact in pharmaceutical industrieson a global scale Different enantiomers or diastereomers ofa molecule often have different biological activity Most ofthe drugs might be soon sold as single enantiomers in thecoming years There is a huge demand for organocatalystsleading to 100 yield 100 ee of the desired product Theneed from chemical industry especially pharmaceutical forreliable asymmetric transformations of molecular skeletonsis higher than ever Therefore asymmetric organocatalysisis in a process of attaining maturity into a very powerful

practical and broadly applicable methodological approach inthe catalytic asymmetric synthesis

7 Some Examples and Developments inCatalyst Structural Variants

Following are the famous examples of organocatalysts

71 Proline and Derivatives The proline catalyzed Robinsonannulation was one of the earliest examples of an enantios-elective reaction using an organic catalyst [85] This aminoacid contains both a nucleophilic secondary amino groupand a carboxylic acid moiety functioning as a Broslashnstedacid The availability of proline in both enantiomeric formsbrings advantages over enzymatic methods Arguably thefirst example of proline catalyzed asymmetric aldol reactionis reported by Hajos and Parrish [70 86 87] The Wieland-Miescher ketone is a useful synthetic building block forwhich a classical asymmetric procedure using (S)-prolinewas published forty years ago [88] It is quite significant thatthe first efficient organocatalyzed asymmetric reactions weredescribed by Hajos amp Parrish [86 87] and by Eder et al [88]

Journal of Catalysts 9

both teams from pharmaceutical companies (Hoffmann-la-Roche and Schering) The asymmetric synthesis of theWieland-Miescher ketone is also based on proline andanother early application was one of the transformations inthe total synthesis of erythromycin by Woodward et al [95]Proline is recognized as a versatile organocatalyst of thesetimes (Scheme 5)

In fact the renewal of proline catalyzed transformationsin early 2000 by D W C MacMillan Carlos F Barbas IIIand Benjamin List saw the renaissance of the concept and itwas the starting point of the word ldquoorganocatalysisrdquo ProfessorAhrendt group reported the first enantioselective organocat-alytic Diels-Alder reaction [96] Proline was identified asan effective organocatalyst for asymmetric aldol reaction[97] The catalytic asymmetric 120572-alkylation of aldehydeswas reported by Vignola and List [98] This transformationhad been accomplished with the help of covalently attachedauxiliaries 120572-Methyl L-proline exhibits higher enantioselec-tivities and improved reaction rates when compared to L-proline In recent years proline especially L-proline hasbeen used to catalyze essential transformations used in thefine chemical and pharmaceutical industries such as thedirect asymmetric aldol reactions [99ndash107] Diels-Alder reac-tions Michael reactions [108ndash115] Mannich reaction [116ndash122] Multicomponent reactions [123 124] and 120572-amination[125] 120572-aminoxylation [126ndash128] 120572-oxyaldehyde dimer-ization [100] 120572-functionalization of carbonyl compounds[129] and 120572-alkylation of aldehydes [130] Organocat-alytic cyclopropanation reactions were typically performedusing catalyst-bound ylides However Kunz and MacMil-lan demonstrated that activation of olefin substrates usingcatalytic (S)-(minus)-indoline-2-carboxylic acid is a viable routefor the formation of highly enantioenriched cyclopropanes[131]

Prof K A Joslashrgensen has made an importantbreakthrough in asymmetric synthesis by developing (R)-and (S)-120572120572-bis[35-bis(trifluoromethyl)phenyl]-2-pyrroli-dinemethanol trimethylsilyl ether as excellent chiral organ-ocatalysts in the direct organocatalytic 120572-functionaliza-tion of aldehydes Diarylprolinol silyl ether reagents werefound to catalyze CndashC CndashN CndashO CndashS and CndashHal bondforming reactions [132ndash138] Cascade or domino reactionsswiftly construct complex biologically important compoundsand minimize waste and also the laboratory operations [139]Endersrsquo group developed proline derived organocatalyst fora chemo- diastereo- and enantioselective three-componentdomino reaction to yield tetrasubstituted cyclohexenecarbaldehydes [140] The four stereogenic centers aregenerated in three consecutive CndashC bond formations thatis MichaelMichaelaldol condensation with high diastereo-and complete enantiocontrolThe synthesis of polyfunctionalcyclohexene building blocks involving proline catalytic stepsis reported in this domino reaction

Though this segment of our review is dedicated to prolineas an important class of organocatalysts it would also be agood place to acknowledge the research contributions fromprofessor Ahrendt et al to the field of organocatalysis [96 99100 103 127 131 141ndash150]

Heterogenized Proline An explosion of research articles inthe area of homogeneous organocatalysis occurredwithin thelast decade or so In addition to the initial proline catalyzedreactions the word ldquoorganocatalysisrdquo covers nowadays manyotherwell-knownorganocatalysts and organic reactions Pro-line immobilized onto some sort of inorganic support pavesthe way towards heterogenization of other organocatalysts[151ndash153] A simple and efficient synthesis of polystyrene-supported proline and prolinamide is reported Polystyrene-supported proline catalyzes the asymmetric aldol reactionbetween cyclohexanone and substituted benzaldehydes inwater High yields diastereoselectivities and ee values havebeen observedThe versatility of this resinwas also confirmedby selenenylation of aldehydes Both proline and prolinamideresins gave high yields Recycling studies showed that theproline resin performs as better heterogeneous organocat-alyst as compared to the prolinamide resin [153] An aldolreaction catalyzed by proline functionalized silica gel wasinvestigated in continuous flow microreactors by reaction-progress kinetic analysis and nonlinear chromatography[154]

Though the research community advocates asymmetricsynthesis for industrial application organocatalysts havebeen seldom applied in industry due to insufficient efficiencyand the difficulties in catalyst separation and recycling[155ndash161] The concept of heterogenizing organocatalyst onsupports combines the advantages of both homogeneousorganocatalysis and heterogeneous recycling Though thismight seem simple and present opportunities in indus-trial chemical processes the research in heterogeneousorganocatalysis demands a multidisciplinary approach byidentifying catalytic activity upon bonding organocatalystcovalently to the support understanding noncovalent inter-action as structure-reactivity and conformation decidingfactor taking into consideration the characteristic propertiesof the supports confinement effects if any and so forthSome recent examples will be described on the applicationsof supported proline as organocatalysts for their preindus-trialization study The latter half of this review in generalirons out the detailed discussion on key trendswith examplesscope challenges and ldquogreenrdquo applications of heterogeneousorganocatalysts

72 Other Amino Acids Barbas and coworkers found theproteinogenic amino acid tryptophan (Figure 4) to be anexcellent organocatalyst for the Mannich reaction of hydrox-yacetone with a variety of imines performed in DMF leadingthe desired anti-amino alcohols in excellent diastereoselec-tivities (up to gt19 1) and enantioselectivities (90ndash98 ee)Similarly t-butyl protected threonine catalyzed the aldolreaction of hydroxyacetone and various aldehydes in NMP togive the corresponding syn-aldol adducts in high yields andgood to excellent enantio- and diastereoselectivities [162]Zhao et al reported [163] the development of an aminoacid based small molecule capable of promoting asymmetricmonosilylation of meso-12-diols Furthermore the catalystcan be recycled with equal efficiency Three-componentreaction involving condensation of aldehyde 13-carbonyl

10 Journal of Catalysts

NH

OH

OH

O

O NHPh

O PhH

H

ON

NH

H

O OH

CO2BnCO2Bn

NO2

R1 R2

Scheme 5

NH

OH

O

H2N

Figure 4 L-Tryptophan

compound and (thio)urea is known as Biginelli reactionVarious organocatalysts such as tartaric acid oxalic acidcitric acid and lactic acid were found effective in producingBiginelli products [164ndash172]

Because of the ldquoprivilegedrdquo green nature of this fieldit has become an obligation for scientific community andacademic institutions to be mindful and teach this branchof catalysis to students and also keep it as a driving force inthe generation and dissemination of knowledge in pursuitof efficient synthetic methodologies and processes usingorganocatalysts The synthesis of new chiral building blocksor complex molecular structures involving organocatalyticstep(s) is being reported almost every day in scientificliterature As it is not possible here to discuss all the catalystsindividually in detail the author decides to present salientdevelopments in organocatalysis and allied research areas

Synthesis of prochiral cyclohexanones by amine cat-alyzed self-Diels-Alder reactions of 120572120573-unsaturated ketonesin water brought coupled the concept of green chemistry

with catalysis Useful asymmetric heterodomino reactionsfor the highly diastereoselective synthesis of symmetri-cal and nonsymmetrical synthons of benzoannelated cen-tropolyquinanes were reported [173 174]

In recent years trials are being made by using aminoacids especially L-proline to catalyze essential transforma-tions in the fine chemical and pharmaceutical industriesTheinterest in this field has thus increased spectacularly in the lastfew years However organocatalytic methods often requirecatalyst loadings as high as 30mol for the achievement ofhigh conversions in reasonable reaction times [175] Somecritics suggest that low turnover numbers might limit thepotential uses of organocatalysis for industrial applicationsProcess development and scale-up are being tested for severalorganocatalytic reactions confirming organocatalysis as avaluable tool for industrial scale solutions Scientists arereporting novel organocatalytic systems in various reputedinternational research journals and those catalysts exhibitvarious valuable functions derived from a variety of struc-tural ionicelectronic and chemical properties Broad varietyof efficient syntheses will contribute to an increasing numberof organocatalytic large scale reactions in the future Theorganocatalysts shall be used in various fields especially inasymmetric organic synthesis

73 Amine and Chiral Vicinal Diamines Proline and pyrro-lidine derivatives commonly known as Hayashi-Joslashrgensencatalysts in the form of ferrocenyl pyrrolidine are appliedas organocatalyst wherein the ferrocene moiety controls theconformational space and a simple alkyl group effectivelycovers a face of the derived enamine (Figure 5) [180]

Journal of Catalysts 11

R

RNR

REthanol rt

N

O

H

N

R R

+

10mol catalyst

R1

R1

R1R2

R3H2N

middotTfOH

Scheme 6

H NH

O

R

trans H N

O

H

RCis

Reactive conformation

Si

O

H

R

H

Ph

O

Ph

HO

SiCl3 Cl3

Scheme 7

Sulzer-Mosse and Alexakis reported chiral amines cat-alyzing asymmetric conjugate addition to nitroolefins andvinyl sulfones via enamine activation [181]

A bifunctional H-bond directing aminocatalytic systemis found to achieve high stereo- and regiocontrol overdienamine mediated hetero-Diels-Alder reaction [183]

Though amine catalysis is constructing a wide varietyof chiral scaffolds in asymmetric synthesis organocatalysiswith amines for nonasymmetric transformations is alsodeveloping very fast [184 185] The [2+2] cycloaddition ofenals with nitroalkenes is catalyzed by a chiral secondaryamine in the presence of an achiral thiourea for the enantio-and diastereoselective synthesis of highly functionalizedcyclobutanes Mechanistically two consecutiveMichael reac-tions proceed through an unprecedented combination ofdienamineiminium activation mode [186] The reactionengineering of dienamine catalysis for single-step synthesesof highly functionalized molecules such as natural productsor bioactive compounds is reviewed in literature [187]

Chin and coworkers have recently reported some pre-liminary theoretical and experimental studies for convertinga parent diamine into other chiral vicinal diamines Thesediamines can be handy as ligands for chiral catalysts or theycanmake chiral heterocyclic rings and betalactams [188ndash190]

There are some CndashC bonds forming reactions catalyzed bysuch diamine organocatalysts (Scheme 6) [191]

74 Amides Recently the synthesis of multifunctional or-ganocatalysts easily obtained by the condensation of (S)-proline with 2-aminopyridine 26-diaminopyridine or 2-aminoimidazole is reported These chiral prolinamides pro-moted the aldol condensation between cyclohexanone anddifferent aromatic aldehydes (up to 98ee) and also catalyzedDiels-Alder and Michael reactions [192 193]

Rationally designed pyrazole amides function as Michaeldonors in urea catalyzed asymmetric Michael reactions withexcellent chemical and optical yields [194]

A structure-activity relationship with regard to for-mamides as organocatalysts is exploredThis study highlightsthat the cis-conformation of secondary formamides is thereactive conformation in the allylation of aldehydes withallyltrichlorosilane (Scheme 7) [195]

75 Imidazolidinones A certain class of imidazolidinonecompounds (also called MacMillan imidazolidinone organ-ocatalysts) function as catalysts for many asymmetric organictransformations such as asymmetric Diels-Alder reactions

12 Journal of Catalysts

O

N

O

H

O

Up to 97 ee

OHH

N

NO

H20 mol catalyst

CHCl3 minus30∘C

C2H5O OC2H5

R1

R1

R2

R2

+

middotCF3CO2H

Scheme 8 Ouellet et al [202]

R

R

N

One favoured conformer

High enantioselectivity

R = alkyl

Fe

Figure 5

The original such compound was derived from the chi-ral biomolecule phenylalanine [196 197] The first highlyenantioselective organocatalytic Diels-Alder reaction usinga chiral organocatalyst was reported in MacMillanrsquos pio-neering work where the activated iminium ion formedthrough condensation of the imidazolidinone and an 120572120573-unsaturated aldehyde reacted with various dienes to give[4+2] cycloadducts in excellent yields and enantioselectivi-ties Ahrendt et al reportedmany other asymmetric reactionssuch as the 13-dipolar cycloadditions Friedel-Crafts alky-lations 120572-chlorinations 120572-fluorinations and intramolecularMichael reactions usingMacMillanrsquos organocatalysts [96 150198ndash201]

Ouellet et al also reported the combination of imida-zolidinone organocatalyst and Hantzsch ester to facilitatethe first enantioselective organocatalytic hydride reductionof 120572120573-unsaturated aldehydes (Scheme 8) [202 203] Thisimitated naturersquos stereoselective enzymatic transfer hydro-genation with NADH cofactor

Noncovalent interaction is a structure-reactivity andconformation deciding factor which requires immediateattention for understanding organocatalysis [204] Of specialinterest would be the identifying and understanding of othernoncovalent interactions such as charge transfer [205] pndashp stacking immobilization [206] and adsorption or entrap-ment of organocatalysts in nanomaterials [207]

Homogeneous and HeterogenizedMacMillanrsquos OrganocatalystAn asymmetric Diels-Alder reaction was catalyzed with highefficiency and recyclability by a soluble ldquoself-supportedrdquochiral organosilica polymer with embedded imidazolidinonecatalytic moieties [208]

76 Chiral Phosphoric Acids BINOL derived phosphoricacids catalyze nucleophilic addition reactions to imine sub-strates A direct Pictet-Spengler reaction was reported usinga geminally disubstituted tryptamine organocatalyst to formisoquinolines in excellent yield and enantiomeric excess[209] Phosphoric acid catalyzing the reduction of an iminewith a Hantzsch ester in good enantiomeric excess was firstlyreported by Rueping et al Hoffmann et al reported animprovement to this methodology [210 211]

Storer research group reported a one-pot reductive ami-nation of a range of methyl ketones and aryl amines [212]Reductive amination of 2-butanone over silylated phosphoricacid MacMillan TiPSY catalyst was obtained with goodenantiomeric excess

Zhou and List published on the use of chiral Broslashnstedacid (R)-TRIP for highly enantioselective synthesis of phar-maceutically relevant 3-substituted cyclohexylamines from26-diketones wherein the achiral amine substrate acceleratesthe cascade reaction before getting incorporated into the finalproduct (Scheme 9) [213]

Rowland et al reported VAPOL derived phosphoric acidcatalyzed addition of sulfonamides to BOC protected arylimines and protected aminals in excellent enantioselectivities[214]

The (R)-TRIP catalyzed the aza-Diels-Alder reaction ofaldimines with Danishefskyrsquos diene to yield piperidinonederivatives with high enantioselectivity Addition of aceticacid was found to improve both reactivity and enantiose-lectivity [215] Six chemical bonds five stereogenic centersand three cycles were formed in one-pot four-componentUgitype reaction catalyzed by a chiral BINOLderived phosphoricacid [216] BINAP is one of the earliy commercially appliedligands in industrial catalysis [217] Amicroporous recyclableheterogeneous catalyst offering excellent enantioselectivitywas made from a 111015840-binaphthalene-221015840-diol (binol) derivedphosphoric acid chloride and was found as active as thecorresponding homogeneous catalyst [218]

Journal of Catalysts 13

O

O

Ph

OEt HH

Ph

HN

OEt

i-Pr

i-Pr

i-Pri-Pr

i-Pr

i-Pr

O

OP O

OH

EtO2C CO2Et

CyclohexaneMS 5 A 50∘C

NH2

(R)-TRIP (10mol)

82 dr = 24 1 er = 98 21 22

Scheme 9 Zhou and List [213]

NO

N NHH N

HO

S

N

H R

BocO-PrTBS-O

Pr-O

HN

Boc

5mol catalyst+

t-Bu

t-Bu t-Bu

(2) TFA 2min(1) Toluene minus30∘C 48hr

86ndash98 ee

Scheme 10

HO OH

O O

Figure 6

77 Chiral Diols Huang et al reported on use of TADDOLs(Figure 6) as Broslashnsted acid organocatalysts in highly stereos-elective hetero-Diels-Alder reactions [219]

The 120572-amination of carbonyl compounds has also beenaccomplished by using the 1-naphthyl TADDOL derivative asa Broslashnsted acid organocatalyst [220] McDougal and Schausreported asymmetric Morita-Baylis-Hillman reaction that

is the addition of cyclohexenone to different aldehydescatalyzed by octahydro-BINOL derived Broslashnsted acid [221]

78 JacobsenThioureas ProfessorsVachal and Jacobsen iden-tified chiral thioureas (Figure 7) as versatile and effectiveorganocatalysts 1mol of the thiourea was reported to havecatalytic activity in the hydrocyanation (Strecker reaction) ofboth aldimines and ketoimines with very high enantioselec-tivities [222]

Imine hydrophosphonylation particularly effective withelectron-withdrawing ester substituents on the phosphatetook place in the presence of 10mol of the catalyst [223]Mannich reactions of BOC protected imines have also beenreported (Scheme 10) [224] with excellent yields and enan-tioselectivities and show heterocyclic substrate tolerance

A variant of thiourea organocatalyst was found to catalyzethe cyanosilylation of ketones and aldehydes in high yieldsand enantiomeric excesses [225] Thiourea organocatalystwas put to use in the acyl-Pictet-Spengler reaction to formtetrahydro-120573-carbolines [226] The acyl-Mannich reactionproviding a route to enantioenriched heterocycles from

14 Journal of Catalysts

N N N

H H NO H

HO

O

O

O

t-Bu

t-Bu

t-Bu

Figure 7

aromatic starting materials and trichloroethyl chloroformate(TrocCl) is also catalyzed by the thiourea organocatalyst[227] Bifunctional thiourea-base catalyzed double-Michaeladdition of benzofuran-2-ones to dienones is reported forthe synthesis of optically enriched spirocyclic benzofuran-2-ones [228] In another interesting example benzoylthiourea-pyrrolidine catalyst was synthesized and used in the asym-metric Michael addition of ketones to nitroalkenes [229]

Primary amine-thioureas were improvised to catalyzedifficult Michael reactions synthesizing (S)-baclofen (R)-baclofen and (S)-phenibut [230]

79 Cinchona Alkaloids The cinchona alkaloids catalyzemany useful processes with high enantioselectivities Asym-metric phase transfer catalysis (PTC) presents a ldquogreenrdquoalternative to homogeneous synthetic organic chemistrymethodologies Cinchona alkaloids are synthetically mod-ified for their usage in asymmetric PTC O-Alkyl N-arylmethyl derivatives of cinchona alkaloid led highly enantiose-lective alkylation of glycine imines to generate 120572-amino acidderivatives And for the same reaction dimeric cinchonaalkaloid obtained 97ndash99 enantiomeric excess [231 232]Cinchona alkaloids deprotonate substrates with relativelyacidic protons forming a contact ion pair between the result-ing anion and protonated amineThis interaction generates achiral pool around the anion and facilitates enantioselectivereactions with electrophiles The control over the formationof quaternary asymmetric centers is essential to obtain highenantiomeric excesses The 120572-functionalization of ketones(Scheme 11) by the addition of TMSCN to the correspondingcyanohydrin in excellent yield and enantiomeric excess iscatalyzed by the (DHQD)

2AQN catalyst [233]

Increasingly remote stereocenters are being targeted inasymmetric aminocatalysis Organocatalytic allylic amina-tion presents an alternative to the conventional palladiumcatalyzed methodology Amination at the remote 120574-positionusing (DHQ)

2PYR forms highly functionalized amine com-

pounds [234]Bella and Joslashrgensenrsquos reported the first enantioselective

conjugate addition of 120573-diketones to both aromatic andaliphatic alkynones using (DHQ)

2PHAL catalyst [235] Cin-

chona based primary amine catalysis is found to offer high

efficiency and reliability in the asymmetric functionalizationof carbonyl compounds [236 237] Organocatalysts derivedfrom cinchona alkaloids function as Lewis base catalyst inthe cyclizations of allenoates with electron deficient olefinsand imines and emerged as important synthetic tool inthe preparation of biologically active and pharmaceuticallyinteresting cyclic compounds including natural products[238] Recently cinchona thioureas have been reported forthe first time as catalysts in the area of asymmetric oxi-dations [239] Cinchona and cinchonidine derived catalystsperform asymmetric direct aldol reaction of pyruvic aldehydedimethyl acetal with isatin derivatives [240] Likewise thereare various other examples reported where cinchona or itsvariants are used as organocatalysts for syntheses of variousbiologically important molecules [241ndash246]

710 Maruoka Phase Transfer Catalysts The chiral catalystforms a host-guest complex with the substrate and shuttlesbetween the standard organic solvent and a second phaseexample catalytic enantioselective enolate alkylation [72]As we know chiral quaternary ammonium catalysts can beuseful in asymmetric synthesis Kitamura et al reported C2-symmetric ammonium salts catalyzing monoalkylation ofglycine derived Schiff bases with alkyl halides to synthesize120572-alkyl-120572-amino acids under remarkably low catalyst loadings[247ndash249]

Utilizing the solubility of aqueous quaternary ammoniumsalts into organic solvents professor Maruoka developedspirotype chiral ammonium salt with two binaphthyl ringsas a novel chiral phase transfer catalyst Figure 8 depicts theorganocatalyst for direct asymmetric aldol reaction of 120573-hydroxy-120572-amino acid derivative

711 Oxazaborolidines Chiral oxazaborolidines (known asCBS oxazaborolidines after Corey Bakshi and Shibata)catalyze the reduction of prochiral ketones imines andoximes to produce chiral alcohols amines and amino alco-hols respectively in high yields and excellent enantiomericexcesses The chiral Lewis acid generated from o-tolyl-CBS-oxazaborolidine after protonation with trifluoromethanesul-fonimide is very useful in the enantioselective Diels-Alderreaction (Scheme 12) [250ndash256]

Journal of Catalysts 15

O NC OTMSN

OH

N

N

OH

N

OO

2 to 20mol catalyst

TMSCN CHCl3

OC2H5

OC2H5

OC2H5

OC2H5

H3CO

C6H5C6H5

OCH3

Scheme 11 Tian et al [233]

OO

O

OO

II

CH3CH3

CH3

H3C

H3C TIPSOTIPSO

H

H

H

PhPh

NB

minus

+

+

(CF3SO2)2N

20mol catalyst

16hoursDichloromethane minus78∘C

Scheme 12 See [250ndash256]

712 Shi Epoxidation Catalyst Tu et al reported a fructosederived ketone in efficient asymmetric epoxidation of trans-olefins (Scheme 13) [257] Epoxidation catalyst is able toepoxidize trans-alkenes and certain cis-alkenes with good toexcellent yields and selectivities [258 259] Marigo et alrsquosgroup reported an asymmetric organocatalytic epoxidationof 120572 120573-unsaturated aldehydes with environmentally friendlyoxidant hydrogen peroxide [260]

713 N-Heterocyclic Carbene (NHC) as Organocatalysts

7131 Rovis Catalyst The conjugate addition of an aldehydeto an 120572120573-unsaturated compound (Stetter reaction) is apractical methodology for the construction of 14-dicarbonylcompounds bearing quaternary stereocenters Triazoliumsalt in the presence of a base functions as an N-heterocycliccarbene organocatalyst (Figure 9) in highly enantioselectiveintramolecular Stetter reactions [261 262]

7132 Bode Catalyst Bodersquos studies on NHCs (Figure 10)mainly involve catalytic generation of reactive speciessuch as enolates homoenolates and activated carboxylates

N-Mesityl substituent on an imidazolium or triazoliumNHCprecursor generates highly enantioselective annulations fromsimple starting materials under mild reaction conditions[263 264] In an interesting example the catalysts facilitatehighly enantioselective cyclopentene forming annulations ofsimple enals and activated enones [265] Redox esterificationsand amidations of 120572-functionalized aldehydes using achiralcatalyst are also reported [266] Uniting unique activationmodes of N-heterocyclic carbene (NHC) catalysts with theconcept of domino reactions a new fast-growing field cameinto the spotlight in last couple of years or so [267ndash269]

Domino Michaelaldol reaction between 2-mercapto-quinoline-3-carbaldehydes and enals was catalyzed by di-phenylprolinol silyl ether producing 2H-thiopyrano[23-b]-quinolines in excellent yields and enantioselectivities [270]Zhao et al reported studies on ldquocooperative NHC andrutheniun redox catalysisrdquo in the oxidative esterificationof aldehydes [271] Blanc et al reported NHC mediatedorganocatalytic one-pot allylstannation to generate syn-diols[272] With enals as starting aldehydes elegant cascadeprocesses have been developed using oxidative carbene catal-ysis [273ndash276] Over the last few years there are examplesreported in literature where various organocatalysts rally

16 Journal of Catalysts

O

Oxone

OO

O

O

OO

R1 R1

R3

R3

R2 R2H2OCH3CN

Scheme 13

F3C

N+

F3C

Brminus

CF3

CF3

Figure 8 See [176]

N

O

N

N

F

F

F

F

F

+BF4minus

Figure 9

domino reactions and attract their application in organicprocesses in industries [174 175 180 181 183]

Apart from the aforementioned organocatalysts thereare other organic systems which upon appropriate acti-vation function as catalysts in useful asymmetric synthe-ses [155ndash157] 12-Dicarbonyl compounds because of theiradjacent multiple reactive centers upon activation act asefficient pronucleophiles in asymmetric organocatalyzed

N

O

NN+

Clminus

Figure 10

sequential or domino transformations including CndashC or CndashN bond formation [277] Cyclopropenone catalyzed con-version of aldoximes and primary amides into nitriles ina one-pot mild reaction widens the scope of the utiliza-tion of cyclopropenones in organic synthesis [278] Thefirst asymmetric organocatalytic synthesis by phosphinecatalyzed [3+2] cycloaddition of allenoates onto fullereneis reported to yield enantiomerically pure carbocyclicfullerene derivatives under mild conditions [279] A new[3+2] cycloadditioncycloreversion strategy for organocat-alytic and thermally allowed carbonyl-olefin metathesis isreported [280] Recently a strong evidence for halogenbond based organocatalysis is reported for the reactionof 1-chloroisochroman with ketene silyl acetals [281] Acidcatalyzed asymmetric acetalizations of aldehydes are alsodescribed [282] beta-Isocupreidine catalyzed the enantios-elective Morita-Baylis-Hillman reaction of maleimides withisatin derivatives to form 3-substituted 3-hydroxyoxindolederivatives [283 284]

Recent advances in asymmetric catalysis resulted in uti-lizing the less discussed electrophilic properties of iminiumtype intermediates in complex annulations of indoles [285286] and also pyridines [287 288] Shibatomi and Narayamadiscussed the catalytic enantioselective 120572-chlorination of car-bonyl compounds and stereospecific substitution reactions ofthe resulting optically active alkyl chlorides [289]

Though there is no relation between the developmentof two different fields of organocatalysis and gold catalysis

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

[1] ldquoOur Common Future Report of the World Commissionon Environment and Development United Nations (UN)Commission on Environment and Development (BrundtlandCommission) 1987rdquo Published as Annex to General Assem-bly document A42427 Development and International Co-operation Environment August 1987

[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

[17] J R Anderson and K C Pratt Introduction To Characterisationand Testing of Catalysts Academic Press Sydney Australia1985

[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

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Journal of

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Advances in

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Analytical Methods in Chemistry

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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Quantum Chemistry

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ElectrochemistryInternational Journal of

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CatalystsJournal of

Journal of Catalysts 9

both teams from pharmaceutical companies (Hoffmann-la-Roche and Schering) The asymmetric synthesis of theWieland-Miescher ketone is also based on proline andanother early application was one of the transformations inthe total synthesis of erythromycin by Woodward et al [95]Proline is recognized as a versatile organocatalyst of thesetimes (Scheme 5)

In fact the renewal of proline catalyzed transformationsin early 2000 by D W C MacMillan Carlos F Barbas IIIand Benjamin List saw the renaissance of the concept and itwas the starting point of the word ldquoorganocatalysisrdquo ProfessorAhrendt group reported the first enantioselective organocat-alytic Diels-Alder reaction [96] Proline was identified asan effective organocatalyst for asymmetric aldol reaction[97] The catalytic asymmetric 120572-alkylation of aldehydeswas reported by Vignola and List [98] This transformationhad been accomplished with the help of covalently attachedauxiliaries 120572-Methyl L-proline exhibits higher enantioselec-tivities and improved reaction rates when compared to L-proline In recent years proline especially L-proline hasbeen used to catalyze essential transformations used in thefine chemical and pharmaceutical industries such as thedirect asymmetric aldol reactions [99ndash107] Diels-Alder reac-tions Michael reactions [108ndash115] Mannich reaction [116ndash122] Multicomponent reactions [123 124] and 120572-amination[125] 120572-aminoxylation [126ndash128] 120572-oxyaldehyde dimer-ization [100] 120572-functionalization of carbonyl compounds[129] and 120572-alkylation of aldehydes [130] Organocat-alytic cyclopropanation reactions were typically performedusing catalyst-bound ylides However Kunz and MacMil-lan demonstrated that activation of olefin substrates usingcatalytic (S)-(minus)-indoline-2-carboxylic acid is a viable routefor the formation of highly enantioenriched cyclopropanes[131]

Prof K A Joslashrgensen has made an importantbreakthrough in asymmetric synthesis by developing (R)-and (S)-120572120572-bis[35-bis(trifluoromethyl)phenyl]-2-pyrroli-dinemethanol trimethylsilyl ether as excellent chiral organ-ocatalysts in the direct organocatalytic 120572-functionaliza-tion of aldehydes Diarylprolinol silyl ether reagents werefound to catalyze CndashC CndashN CndashO CndashS and CndashHal bondforming reactions [132ndash138] Cascade or domino reactionsswiftly construct complex biologically important compoundsand minimize waste and also the laboratory operations [139]Endersrsquo group developed proline derived organocatalyst fora chemo- diastereo- and enantioselective three-componentdomino reaction to yield tetrasubstituted cyclohexenecarbaldehydes [140] The four stereogenic centers aregenerated in three consecutive CndashC bond formations thatis MichaelMichaelaldol condensation with high diastereo-and complete enantiocontrolThe synthesis of polyfunctionalcyclohexene building blocks involving proline catalytic stepsis reported in this domino reaction

Though this segment of our review is dedicated to prolineas an important class of organocatalysts it would also be agood place to acknowledge the research contributions fromprofessor Ahrendt et al to the field of organocatalysis [96 99100 103 127 131 141ndash150]

Heterogenized Proline An explosion of research articles inthe area of homogeneous organocatalysis occurredwithin thelast decade or so In addition to the initial proline catalyzedreactions the word ldquoorganocatalysisrdquo covers nowadays manyotherwell-knownorganocatalysts and organic reactions Pro-line immobilized onto some sort of inorganic support pavesthe way towards heterogenization of other organocatalysts[151ndash153] A simple and efficient synthesis of polystyrene-supported proline and prolinamide is reported Polystyrene-supported proline catalyzes the asymmetric aldol reactionbetween cyclohexanone and substituted benzaldehydes inwater High yields diastereoselectivities and ee values havebeen observedThe versatility of this resinwas also confirmedby selenenylation of aldehydes Both proline and prolinamideresins gave high yields Recycling studies showed that theproline resin performs as better heterogeneous organocat-alyst as compared to the prolinamide resin [153] An aldolreaction catalyzed by proline functionalized silica gel wasinvestigated in continuous flow microreactors by reaction-progress kinetic analysis and nonlinear chromatography[154]

Though the research community advocates asymmetricsynthesis for industrial application organocatalysts havebeen seldom applied in industry due to insufficient efficiencyand the difficulties in catalyst separation and recycling[155ndash161] The concept of heterogenizing organocatalyst onsupports combines the advantages of both homogeneousorganocatalysis and heterogeneous recycling Though thismight seem simple and present opportunities in indus-trial chemical processes the research in heterogeneousorganocatalysis demands a multidisciplinary approach byidentifying catalytic activity upon bonding organocatalystcovalently to the support understanding noncovalent inter-action as structure-reactivity and conformation decidingfactor taking into consideration the characteristic propertiesof the supports confinement effects if any and so forthSome recent examples will be described on the applicationsof supported proline as organocatalysts for their preindus-trialization study The latter half of this review in generalirons out the detailed discussion on key trendswith examplesscope challenges and ldquogreenrdquo applications of heterogeneousorganocatalysts

72 Other Amino Acids Barbas and coworkers found theproteinogenic amino acid tryptophan (Figure 4) to be anexcellent organocatalyst for the Mannich reaction of hydrox-yacetone with a variety of imines performed in DMF leadingthe desired anti-amino alcohols in excellent diastereoselec-tivities (up to gt19 1) and enantioselectivities (90ndash98 ee)Similarly t-butyl protected threonine catalyzed the aldolreaction of hydroxyacetone and various aldehydes in NMP togive the corresponding syn-aldol adducts in high yields andgood to excellent enantio- and diastereoselectivities [162]Zhao et al reported [163] the development of an aminoacid based small molecule capable of promoting asymmetricmonosilylation of meso-12-diols Furthermore the catalystcan be recycled with equal efficiency Three-componentreaction involving condensation of aldehyde 13-carbonyl

10 Journal of Catalysts

NH

OH

OH

O

O NHPh

O PhH

H

ON

NH

H

O OH

CO2BnCO2Bn

NO2

R1 R2

Scheme 5

NH

OH

O

H2N

Figure 4 L-Tryptophan

compound and (thio)urea is known as Biginelli reactionVarious organocatalysts such as tartaric acid oxalic acidcitric acid and lactic acid were found effective in producingBiginelli products [164ndash172]

Because of the ldquoprivilegedrdquo green nature of this fieldit has become an obligation for scientific community andacademic institutions to be mindful and teach this branchof catalysis to students and also keep it as a driving force inthe generation and dissemination of knowledge in pursuitof efficient synthetic methodologies and processes usingorganocatalysts The synthesis of new chiral building blocksor complex molecular structures involving organocatalyticstep(s) is being reported almost every day in scientificliterature As it is not possible here to discuss all the catalystsindividually in detail the author decides to present salientdevelopments in organocatalysis and allied research areas

Synthesis of prochiral cyclohexanones by amine cat-alyzed self-Diels-Alder reactions of 120572120573-unsaturated ketonesin water brought coupled the concept of green chemistry

with catalysis Useful asymmetric heterodomino reactionsfor the highly diastereoselective synthesis of symmetri-cal and nonsymmetrical synthons of benzoannelated cen-tropolyquinanes were reported [173 174]

In recent years trials are being made by using aminoacids especially L-proline to catalyze essential transforma-tions in the fine chemical and pharmaceutical industriesTheinterest in this field has thus increased spectacularly in the lastfew years However organocatalytic methods often requirecatalyst loadings as high as 30mol for the achievement ofhigh conversions in reasonable reaction times [175] Somecritics suggest that low turnover numbers might limit thepotential uses of organocatalysis for industrial applicationsProcess development and scale-up are being tested for severalorganocatalytic reactions confirming organocatalysis as avaluable tool for industrial scale solutions Scientists arereporting novel organocatalytic systems in various reputedinternational research journals and those catalysts exhibitvarious valuable functions derived from a variety of struc-tural ionicelectronic and chemical properties Broad varietyof efficient syntheses will contribute to an increasing numberof organocatalytic large scale reactions in the future Theorganocatalysts shall be used in various fields especially inasymmetric organic synthesis

73 Amine and Chiral Vicinal Diamines Proline and pyrro-lidine derivatives commonly known as Hayashi-Joslashrgensencatalysts in the form of ferrocenyl pyrrolidine are appliedas organocatalyst wherein the ferrocene moiety controls theconformational space and a simple alkyl group effectivelycovers a face of the derived enamine (Figure 5) [180]

Journal of Catalysts 11

R

RNR

REthanol rt

N

O

H

N

R R

+

10mol catalyst

R1

R1

R1R2

R3H2N

middotTfOH

Scheme 6

H NH

O

R

trans H N

O

H

RCis

Reactive conformation

Si

O

H

R

H

Ph

O

Ph

HO

SiCl3 Cl3

Scheme 7

Sulzer-Mosse and Alexakis reported chiral amines cat-alyzing asymmetric conjugate addition to nitroolefins andvinyl sulfones via enamine activation [181]

A bifunctional H-bond directing aminocatalytic systemis found to achieve high stereo- and regiocontrol overdienamine mediated hetero-Diels-Alder reaction [183]

Though amine catalysis is constructing a wide varietyof chiral scaffolds in asymmetric synthesis organocatalysiswith amines for nonasymmetric transformations is alsodeveloping very fast [184 185] The [2+2] cycloaddition ofenals with nitroalkenes is catalyzed by a chiral secondaryamine in the presence of an achiral thiourea for the enantio-and diastereoselective synthesis of highly functionalizedcyclobutanes Mechanistically two consecutiveMichael reac-tions proceed through an unprecedented combination ofdienamineiminium activation mode [186] The reactionengineering of dienamine catalysis for single-step synthesesof highly functionalized molecules such as natural productsor bioactive compounds is reviewed in literature [187]

Chin and coworkers have recently reported some pre-liminary theoretical and experimental studies for convertinga parent diamine into other chiral vicinal diamines Thesediamines can be handy as ligands for chiral catalysts or theycanmake chiral heterocyclic rings and betalactams [188ndash190]

There are some CndashC bonds forming reactions catalyzed bysuch diamine organocatalysts (Scheme 6) [191]

74 Amides Recently the synthesis of multifunctional or-ganocatalysts easily obtained by the condensation of (S)-proline with 2-aminopyridine 26-diaminopyridine or 2-aminoimidazole is reported These chiral prolinamides pro-moted the aldol condensation between cyclohexanone anddifferent aromatic aldehydes (up to 98ee) and also catalyzedDiels-Alder and Michael reactions [192 193]

Rationally designed pyrazole amides function as Michaeldonors in urea catalyzed asymmetric Michael reactions withexcellent chemical and optical yields [194]

A structure-activity relationship with regard to for-mamides as organocatalysts is exploredThis study highlightsthat the cis-conformation of secondary formamides is thereactive conformation in the allylation of aldehydes withallyltrichlorosilane (Scheme 7) [195]

75 Imidazolidinones A certain class of imidazolidinonecompounds (also called MacMillan imidazolidinone organ-ocatalysts) function as catalysts for many asymmetric organictransformations such as asymmetric Diels-Alder reactions

12 Journal of Catalysts

O

N

O

H

O

Up to 97 ee

OHH

N

NO

H20 mol catalyst

CHCl3 minus30∘C

C2H5O OC2H5

R1

R1

R2

R2

+

middotCF3CO2H

Scheme 8 Ouellet et al [202]

R

R

N

One favoured conformer

High enantioselectivity

R = alkyl

Fe

Figure 5

The original such compound was derived from the chi-ral biomolecule phenylalanine [196 197] The first highlyenantioselective organocatalytic Diels-Alder reaction usinga chiral organocatalyst was reported in MacMillanrsquos pio-neering work where the activated iminium ion formedthrough condensation of the imidazolidinone and an 120572120573-unsaturated aldehyde reacted with various dienes to give[4+2] cycloadducts in excellent yields and enantioselectivi-ties Ahrendt et al reportedmany other asymmetric reactionssuch as the 13-dipolar cycloadditions Friedel-Crafts alky-lations 120572-chlorinations 120572-fluorinations and intramolecularMichael reactions usingMacMillanrsquos organocatalysts [96 150198ndash201]

Ouellet et al also reported the combination of imida-zolidinone organocatalyst and Hantzsch ester to facilitatethe first enantioselective organocatalytic hydride reductionof 120572120573-unsaturated aldehydes (Scheme 8) [202 203] Thisimitated naturersquos stereoselective enzymatic transfer hydro-genation with NADH cofactor

Noncovalent interaction is a structure-reactivity andconformation deciding factor which requires immediateattention for understanding organocatalysis [204] Of specialinterest would be the identifying and understanding of othernoncovalent interactions such as charge transfer [205] pndashp stacking immobilization [206] and adsorption or entrap-ment of organocatalysts in nanomaterials [207]

Homogeneous and HeterogenizedMacMillanrsquos OrganocatalystAn asymmetric Diels-Alder reaction was catalyzed with highefficiency and recyclability by a soluble ldquoself-supportedrdquochiral organosilica polymer with embedded imidazolidinonecatalytic moieties [208]

76 Chiral Phosphoric Acids BINOL derived phosphoricacids catalyze nucleophilic addition reactions to imine sub-strates A direct Pictet-Spengler reaction was reported usinga geminally disubstituted tryptamine organocatalyst to formisoquinolines in excellent yield and enantiomeric excess[209] Phosphoric acid catalyzing the reduction of an iminewith a Hantzsch ester in good enantiomeric excess was firstlyreported by Rueping et al Hoffmann et al reported animprovement to this methodology [210 211]

Storer research group reported a one-pot reductive ami-nation of a range of methyl ketones and aryl amines [212]Reductive amination of 2-butanone over silylated phosphoricacid MacMillan TiPSY catalyst was obtained with goodenantiomeric excess

Zhou and List published on the use of chiral Broslashnstedacid (R)-TRIP for highly enantioselective synthesis of phar-maceutically relevant 3-substituted cyclohexylamines from26-diketones wherein the achiral amine substrate acceleratesthe cascade reaction before getting incorporated into the finalproduct (Scheme 9) [213]

Rowland et al reported VAPOL derived phosphoric acidcatalyzed addition of sulfonamides to BOC protected arylimines and protected aminals in excellent enantioselectivities[214]

The (R)-TRIP catalyzed the aza-Diels-Alder reaction ofaldimines with Danishefskyrsquos diene to yield piperidinonederivatives with high enantioselectivity Addition of aceticacid was found to improve both reactivity and enantiose-lectivity [215] Six chemical bonds five stereogenic centersand three cycles were formed in one-pot four-componentUgitype reaction catalyzed by a chiral BINOLderived phosphoricacid [216] BINAP is one of the earliy commercially appliedligands in industrial catalysis [217] Amicroporous recyclableheterogeneous catalyst offering excellent enantioselectivitywas made from a 111015840-binaphthalene-221015840-diol (binol) derivedphosphoric acid chloride and was found as active as thecorresponding homogeneous catalyst [218]

Journal of Catalysts 13

O

O

Ph

OEt HH

Ph

HN

OEt

i-Pr

i-Pr

i-Pri-Pr

i-Pr

i-Pr

O

OP O

OH

EtO2C CO2Et

CyclohexaneMS 5 A 50∘C

NH2

(R)-TRIP (10mol)

82 dr = 24 1 er = 98 21 22

Scheme 9 Zhou and List [213]

NO

N NHH N

HO

S

N

H R

BocO-PrTBS-O

Pr-O

HN

Boc

5mol catalyst+

t-Bu

t-Bu t-Bu

(2) TFA 2min(1) Toluene minus30∘C 48hr

86ndash98 ee

Scheme 10

HO OH

O O

Figure 6

77 Chiral Diols Huang et al reported on use of TADDOLs(Figure 6) as Broslashnsted acid organocatalysts in highly stereos-elective hetero-Diels-Alder reactions [219]

The 120572-amination of carbonyl compounds has also beenaccomplished by using the 1-naphthyl TADDOL derivative asa Broslashnsted acid organocatalyst [220] McDougal and Schausreported asymmetric Morita-Baylis-Hillman reaction that

is the addition of cyclohexenone to different aldehydescatalyzed by octahydro-BINOL derived Broslashnsted acid [221]

78 JacobsenThioureas ProfessorsVachal and Jacobsen iden-tified chiral thioureas (Figure 7) as versatile and effectiveorganocatalysts 1mol of the thiourea was reported to havecatalytic activity in the hydrocyanation (Strecker reaction) ofboth aldimines and ketoimines with very high enantioselec-tivities [222]

Imine hydrophosphonylation particularly effective withelectron-withdrawing ester substituents on the phosphatetook place in the presence of 10mol of the catalyst [223]Mannich reactions of BOC protected imines have also beenreported (Scheme 10) [224] with excellent yields and enan-tioselectivities and show heterocyclic substrate tolerance

A variant of thiourea organocatalyst was found to catalyzethe cyanosilylation of ketones and aldehydes in high yieldsand enantiomeric excesses [225] Thiourea organocatalystwas put to use in the acyl-Pictet-Spengler reaction to formtetrahydro-120573-carbolines [226] The acyl-Mannich reactionproviding a route to enantioenriched heterocycles from

14 Journal of Catalysts

N N N

H H NO H

HO

O

O

O

t-Bu

t-Bu

t-Bu

Figure 7

aromatic starting materials and trichloroethyl chloroformate(TrocCl) is also catalyzed by the thiourea organocatalyst[227] Bifunctional thiourea-base catalyzed double-Michaeladdition of benzofuran-2-ones to dienones is reported forthe synthesis of optically enriched spirocyclic benzofuran-2-ones [228] In another interesting example benzoylthiourea-pyrrolidine catalyst was synthesized and used in the asym-metric Michael addition of ketones to nitroalkenes [229]

Primary amine-thioureas were improvised to catalyzedifficult Michael reactions synthesizing (S)-baclofen (R)-baclofen and (S)-phenibut [230]

79 Cinchona Alkaloids The cinchona alkaloids catalyzemany useful processes with high enantioselectivities Asym-metric phase transfer catalysis (PTC) presents a ldquogreenrdquoalternative to homogeneous synthetic organic chemistrymethodologies Cinchona alkaloids are synthetically mod-ified for their usage in asymmetric PTC O-Alkyl N-arylmethyl derivatives of cinchona alkaloid led highly enantiose-lective alkylation of glycine imines to generate 120572-amino acidderivatives And for the same reaction dimeric cinchonaalkaloid obtained 97ndash99 enantiomeric excess [231 232]Cinchona alkaloids deprotonate substrates with relativelyacidic protons forming a contact ion pair between the result-ing anion and protonated amineThis interaction generates achiral pool around the anion and facilitates enantioselectivereactions with electrophiles The control over the formationof quaternary asymmetric centers is essential to obtain highenantiomeric excesses The 120572-functionalization of ketones(Scheme 11) by the addition of TMSCN to the correspondingcyanohydrin in excellent yield and enantiomeric excess iscatalyzed by the (DHQD)

2AQN catalyst [233]

Increasingly remote stereocenters are being targeted inasymmetric aminocatalysis Organocatalytic allylic amina-tion presents an alternative to the conventional palladiumcatalyzed methodology Amination at the remote 120574-positionusing (DHQ)

2PYR forms highly functionalized amine com-

pounds [234]Bella and Joslashrgensenrsquos reported the first enantioselective

conjugate addition of 120573-diketones to both aromatic andaliphatic alkynones using (DHQ)

2PHAL catalyst [235] Cin-

chona based primary amine catalysis is found to offer high

efficiency and reliability in the asymmetric functionalizationof carbonyl compounds [236 237] Organocatalysts derivedfrom cinchona alkaloids function as Lewis base catalyst inthe cyclizations of allenoates with electron deficient olefinsand imines and emerged as important synthetic tool inthe preparation of biologically active and pharmaceuticallyinteresting cyclic compounds including natural products[238] Recently cinchona thioureas have been reported forthe first time as catalysts in the area of asymmetric oxi-dations [239] Cinchona and cinchonidine derived catalystsperform asymmetric direct aldol reaction of pyruvic aldehydedimethyl acetal with isatin derivatives [240] Likewise thereare various other examples reported where cinchona or itsvariants are used as organocatalysts for syntheses of variousbiologically important molecules [241ndash246]

710 Maruoka Phase Transfer Catalysts The chiral catalystforms a host-guest complex with the substrate and shuttlesbetween the standard organic solvent and a second phaseexample catalytic enantioselective enolate alkylation [72]As we know chiral quaternary ammonium catalysts can beuseful in asymmetric synthesis Kitamura et al reported C2-symmetric ammonium salts catalyzing monoalkylation ofglycine derived Schiff bases with alkyl halides to synthesize120572-alkyl-120572-amino acids under remarkably low catalyst loadings[247ndash249]

Utilizing the solubility of aqueous quaternary ammoniumsalts into organic solvents professor Maruoka developedspirotype chiral ammonium salt with two binaphthyl ringsas a novel chiral phase transfer catalyst Figure 8 depicts theorganocatalyst for direct asymmetric aldol reaction of 120573-hydroxy-120572-amino acid derivative

711 Oxazaborolidines Chiral oxazaborolidines (known asCBS oxazaborolidines after Corey Bakshi and Shibata)catalyze the reduction of prochiral ketones imines andoximes to produce chiral alcohols amines and amino alco-hols respectively in high yields and excellent enantiomericexcesses The chiral Lewis acid generated from o-tolyl-CBS-oxazaborolidine after protonation with trifluoromethanesul-fonimide is very useful in the enantioselective Diels-Alderreaction (Scheme 12) [250ndash256]

Journal of Catalysts 15

O NC OTMSN

OH

N

N

OH

N

OO

2 to 20mol catalyst

TMSCN CHCl3

OC2H5

OC2H5

OC2H5

OC2H5

H3CO

C6H5C6H5

OCH3

Scheme 11 Tian et al [233]

OO

O

OO

II

CH3CH3

CH3

H3C

H3C TIPSOTIPSO

H

H

H

PhPh

NB

minus

+

+

(CF3SO2)2N

20mol catalyst

16hoursDichloromethane minus78∘C

Scheme 12 See [250ndash256]

712 Shi Epoxidation Catalyst Tu et al reported a fructosederived ketone in efficient asymmetric epoxidation of trans-olefins (Scheme 13) [257] Epoxidation catalyst is able toepoxidize trans-alkenes and certain cis-alkenes with good toexcellent yields and selectivities [258 259] Marigo et alrsquosgroup reported an asymmetric organocatalytic epoxidationof 120572 120573-unsaturated aldehydes with environmentally friendlyoxidant hydrogen peroxide [260]

713 N-Heterocyclic Carbene (NHC) as Organocatalysts

7131 Rovis Catalyst The conjugate addition of an aldehydeto an 120572120573-unsaturated compound (Stetter reaction) is apractical methodology for the construction of 14-dicarbonylcompounds bearing quaternary stereocenters Triazoliumsalt in the presence of a base functions as an N-heterocycliccarbene organocatalyst (Figure 9) in highly enantioselectiveintramolecular Stetter reactions [261 262]

7132 Bode Catalyst Bodersquos studies on NHCs (Figure 10)mainly involve catalytic generation of reactive speciessuch as enolates homoenolates and activated carboxylates

N-Mesityl substituent on an imidazolium or triazoliumNHCprecursor generates highly enantioselective annulations fromsimple starting materials under mild reaction conditions[263 264] In an interesting example the catalysts facilitatehighly enantioselective cyclopentene forming annulations ofsimple enals and activated enones [265] Redox esterificationsand amidations of 120572-functionalized aldehydes using achiralcatalyst are also reported [266] Uniting unique activationmodes of N-heterocyclic carbene (NHC) catalysts with theconcept of domino reactions a new fast-growing field cameinto the spotlight in last couple of years or so [267ndash269]

Domino Michaelaldol reaction between 2-mercapto-quinoline-3-carbaldehydes and enals was catalyzed by di-phenylprolinol silyl ether producing 2H-thiopyrano[23-b]-quinolines in excellent yields and enantioselectivities [270]Zhao et al reported studies on ldquocooperative NHC andrutheniun redox catalysisrdquo in the oxidative esterificationof aldehydes [271] Blanc et al reported NHC mediatedorganocatalytic one-pot allylstannation to generate syn-diols[272] With enals as starting aldehydes elegant cascadeprocesses have been developed using oxidative carbene catal-ysis [273ndash276] Over the last few years there are examplesreported in literature where various organocatalysts rally

16 Journal of Catalysts

O

Oxone

OO

O

O

OO

R1 R1

R3

R3

R2 R2H2OCH3CN

Scheme 13

F3C

N+

F3C

Brminus

CF3

CF3

Figure 8 See [176]

N

O

N

N

F

F

F

F

F

+BF4minus

Figure 9

domino reactions and attract their application in organicprocesses in industries [174 175 180 181 183]

Apart from the aforementioned organocatalysts thereare other organic systems which upon appropriate acti-vation function as catalysts in useful asymmetric synthe-ses [155ndash157] 12-Dicarbonyl compounds because of theiradjacent multiple reactive centers upon activation act asefficient pronucleophiles in asymmetric organocatalyzed

N

O

NN+

Clminus

Figure 10

sequential or domino transformations including CndashC or CndashN bond formation [277] Cyclopropenone catalyzed con-version of aldoximes and primary amides into nitriles ina one-pot mild reaction widens the scope of the utiliza-tion of cyclopropenones in organic synthesis [278] Thefirst asymmetric organocatalytic synthesis by phosphinecatalyzed [3+2] cycloaddition of allenoates onto fullereneis reported to yield enantiomerically pure carbocyclicfullerene derivatives under mild conditions [279] A new[3+2] cycloadditioncycloreversion strategy for organocat-alytic and thermally allowed carbonyl-olefin metathesis isreported [280] Recently a strong evidence for halogenbond based organocatalysis is reported for the reactionof 1-chloroisochroman with ketene silyl acetals [281] Acidcatalyzed asymmetric acetalizations of aldehydes are alsodescribed [282] beta-Isocupreidine catalyzed the enantios-elective Morita-Baylis-Hillman reaction of maleimides withisatin derivatives to form 3-substituted 3-hydroxyoxindolederivatives [283 284]

Recent advances in asymmetric catalysis resulted in uti-lizing the less discussed electrophilic properties of iminiumtype intermediates in complex annulations of indoles [285286] and also pyridines [287 288] Shibatomi and Narayamadiscussed the catalytic enantioselective 120572-chlorination of car-bonyl compounds and stereospecific substitution reactions ofthe resulting optically active alkyl chlorides [289]

Though there is no relation between the developmentof two different fields of organocatalysis and gold catalysis

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

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[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

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[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

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[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

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Analytical Methods in Chemistry

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Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

10 Journal of Catalysts

NH

OH

OH

O

O NHPh

O PhH

H

ON

NH

H

O OH

CO2BnCO2Bn

NO2

R1 R2

Scheme 5

NH

OH

O

H2N

Figure 4 L-Tryptophan

compound and (thio)urea is known as Biginelli reactionVarious organocatalysts such as tartaric acid oxalic acidcitric acid and lactic acid were found effective in producingBiginelli products [164ndash172]

Because of the ldquoprivilegedrdquo green nature of this fieldit has become an obligation for scientific community andacademic institutions to be mindful and teach this branchof catalysis to students and also keep it as a driving force inthe generation and dissemination of knowledge in pursuitof efficient synthetic methodologies and processes usingorganocatalysts The synthesis of new chiral building blocksor complex molecular structures involving organocatalyticstep(s) is being reported almost every day in scientificliterature As it is not possible here to discuss all the catalystsindividually in detail the author decides to present salientdevelopments in organocatalysis and allied research areas

Synthesis of prochiral cyclohexanones by amine cat-alyzed self-Diels-Alder reactions of 120572120573-unsaturated ketonesin water brought coupled the concept of green chemistry

with catalysis Useful asymmetric heterodomino reactionsfor the highly diastereoselective synthesis of symmetri-cal and nonsymmetrical synthons of benzoannelated cen-tropolyquinanes were reported [173 174]

In recent years trials are being made by using aminoacids especially L-proline to catalyze essential transforma-tions in the fine chemical and pharmaceutical industriesTheinterest in this field has thus increased spectacularly in the lastfew years However organocatalytic methods often requirecatalyst loadings as high as 30mol for the achievement ofhigh conversions in reasonable reaction times [175] Somecritics suggest that low turnover numbers might limit thepotential uses of organocatalysis for industrial applicationsProcess development and scale-up are being tested for severalorganocatalytic reactions confirming organocatalysis as avaluable tool for industrial scale solutions Scientists arereporting novel organocatalytic systems in various reputedinternational research journals and those catalysts exhibitvarious valuable functions derived from a variety of struc-tural ionicelectronic and chemical properties Broad varietyof efficient syntheses will contribute to an increasing numberof organocatalytic large scale reactions in the future Theorganocatalysts shall be used in various fields especially inasymmetric organic synthesis

73 Amine and Chiral Vicinal Diamines Proline and pyrro-lidine derivatives commonly known as Hayashi-Joslashrgensencatalysts in the form of ferrocenyl pyrrolidine are appliedas organocatalyst wherein the ferrocene moiety controls theconformational space and a simple alkyl group effectivelycovers a face of the derived enamine (Figure 5) [180]

Journal of Catalysts 11

R

RNR

REthanol rt

N

O

H

N

R R

+

10mol catalyst

R1

R1

R1R2

R3H2N

middotTfOH

Scheme 6

H NH

O

R

trans H N

O

H

RCis

Reactive conformation

Si

O

H

R

H

Ph

O

Ph

HO

SiCl3 Cl3

Scheme 7

Sulzer-Mosse and Alexakis reported chiral amines cat-alyzing asymmetric conjugate addition to nitroolefins andvinyl sulfones via enamine activation [181]

A bifunctional H-bond directing aminocatalytic systemis found to achieve high stereo- and regiocontrol overdienamine mediated hetero-Diels-Alder reaction [183]

Though amine catalysis is constructing a wide varietyof chiral scaffolds in asymmetric synthesis organocatalysiswith amines for nonasymmetric transformations is alsodeveloping very fast [184 185] The [2+2] cycloaddition ofenals with nitroalkenes is catalyzed by a chiral secondaryamine in the presence of an achiral thiourea for the enantio-and diastereoselective synthesis of highly functionalizedcyclobutanes Mechanistically two consecutiveMichael reac-tions proceed through an unprecedented combination ofdienamineiminium activation mode [186] The reactionengineering of dienamine catalysis for single-step synthesesof highly functionalized molecules such as natural productsor bioactive compounds is reviewed in literature [187]

Chin and coworkers have recently reported some pre-liminary theoretical and experimental studies for convertinga parent diamine into other chiral vicinal diamines Thesediamines can be handy as ligands for chiral catalysts or theycanmake chiral heterocyclic rings and betalactams [188ndash190]

There are some CndashC bonds forming reactions catalyzed bysuch diamine organocatalysts (Scheme 6) [191]

74 Amides Recently the synthesis of multifunctional or-ganocatalysts easily obtained by the condensation of (S)-proline with 2-aminopyridine 26-diaminopyridine or 2-aminoimidazole is reported These chiral prolinamides pro-moted the aldol condensation between cyclohexanone anddifferent aromatic aldehydes (up to 98ee) and also catalyzedDiels-Alder and Michael reactions [192 193]

Rationally designed pyrazole amides function as Michaeldonors in urea catalyzed asymmetric Michael reactions withexcellent chemical and optical yields [194]

A structure-activity relationship with regard to for-mamides as organocatalysts is exploredThis study highlightsthat the cis-conformation of secondary formamides is thereactive conformation in the allylation of aldehydes withallyltrichlorosilane (Scheme 7) [195]

75 Imidazolidinones A certain class of imidazolidinonecompounds (also called MacMillan imidazolidinone organ-ocatalysts) function as catalysts for many asymmetric organictransformations such as asymmetric Diels-Alder reactions

12 Journal of Catalysts

O

N

O

H

O

Up to 97 ee

OHH

N

NO

H20 mol catalyst

CHCl3 minus30∘C

C2H5O OC2H5

R1

R1

R2

R2

+

middotCF3CO2H

Scheme 8 Ouellet et al [202]

R

R

N

One favoured conformer

High enantioselectivity

R = alkyl

Fe

Figure 5

The original such compound was derived from the chi-ral biomolecule phenylalanine [196 197] The first highlyenantioselective organocatalytic Diels-Alder reaction usinga chiral organocatalyst was reported in MacMillanrsquos pio-neering work where the activated iminium ion formedthrough condensation of the imidazolidinone and an 120572120573-unsaturated aldehyde reacted with various dienes to give[4+2] cycloadducts in excellent yields and enantioselectivi-ties Ahrendt et al reportedmany other asymmetric reactionssuch as the 13-dipolar cycloadditions Friedel-Crafts alky-lations 120572-chlorinations 120572-fluorinations and intramolecularMichael reactions usingMacMillanrsquos organocatalysts [96 150198ndash201]

Ouellet et al also reported the combination of imida-zolidinone organocatalyst and Hantzsch ester to facilitatethe first enantioselective organocatalytic hydride reductionof 120572120573-unsaturated aldehydes (Scheme 8) [202 203] Thisimitated naturersquos stereoselective enzymatic transfer hydro-genation with NADH cofactor

Noncovalent interaction is a structure-reactivity andconformation deciding factor which requires immediateattention for understanding organocatalysis [204] Of specialinterest would be the identifying and understanding of othernoncovalent interactions such as charge transfer [205] pndashp stacking immobilization [206] and adsorption or entrap-ment of organocatalysts in nanomaterials [207]

Homogeneous and HeterogenizedMacMillanrsquos OrganocatalystAn asymmetric Diels-Alder reaction was catalyzed with highefficiency and recyclability by a soluble ldquoself-supportedrdquochiral organosilica polymer with embedded imidazolidinonecatalytic moieties [208]

76 Chiral Phosphoric Acids BINOL derived phosphoricacids catalyze nucleophilic addition reactions to imine sub-strates A direct Pictet-Spengler reaction was reported usinga geminally disubstituted tryptamine organocatalyst to formisoquinolines in excellent yield and enantiomeric excess[209] Phosphoric acid catalyzing the reduction of an iminewith a Hantzsch ester in good enantiomeric excess was firstlyreported by Rueping et al Hoffmann et al reported animprovement to this methodology [210 211]

Storer research group reported a one-pot reductive ami-nation of a range of methyl ketones and aryl amines [212]Reductive amination of 2-butanone over silylated phosphoricacid MacMillan TiPSY catalyst was obtained with goodenantiomeric excess

Zhou and List published on the use of chiral Broslashnstedacid (R)-TRIP for highly enantioselective synthesis of phar-maceutically relevant 3-substituted cyclohexylamines from26-diketones wherein the achiral amine substrate acceleratesthe cascade reaction before getting incorporated into the finalproduct (Scheme 9) [213]

Rowland et al reported VAPOL derived phosphoric acidcatalyzed addition of sulfonamides to BOC protected arylimines and protected aminals in excellent enantioselectivities[214]

The (R)-TRIP catalyzed the aza-Diels-Alder reaction ofaldimines with Danishefskyrsquos diene to yield piperidinonederivatives with high enantioselectivity Addition of aceticacid was found to improve both reactivity and enantiose-lectivity [215] Six chemical bonds five stereogenic centersand three cycles were formed in one-pot four-componentUgitype reaction catalyzed by a chiral BINOLderived phosphoricacid [216] BINAP is one of the earliy commercially appliedligands in industrial catalysis [217] Amicroporous recyclableheterogeneous catalyst offering excellent enantioselectivitywas made from a 111015840-binaphthalene-221015840-diol (binol) derivedphosphoric acid chloride and was found as active as thecorresponding homogeneous catalyst [218]

Journal of Catalysts 13

O

O

Ph

OEt HH

Ph

HN

OEt

i-Pr

i-Pr

i-Pri-Pr

i-Pr

i-Pr

O

OP O

OH

EtO2C CO2Et

CyclohexaneMS 5 A 50∘C

NH2

(R)-TRIP (10mol)

82 dr = 24 1 er = 98 21 22

Scheme 9 Zhou and List [213]

NO

N NHH N

HO

S

N

H R

BocO-PrTBS-O

Pr-O

HN

Boc

5mol catalyst+

t-Bu

t-Bu t-Bu

(2) TFA 2min(1) Toluene minus30∘C 48hr

86ndash98 ee

Scheme 10

HO OH

O O

Figure 6

77 Chiral Diols Huang et al reported on use of TADDOLs(Figure 6) as Broslashnsted acid organocatalysts in highly stereos-elective hetero-Diels-Alder reactions [219]

The 120572-amination of carbonyl compounds has also beenaccomplished by using the 1-naphthyl TADDOL derivative asa Broslashnsted acid organocatalyst [220] McDougal and Schausreported asymmetric Morita-Baylis-Hillman reaction that

is the addition of cyclohexenone to different aldehydescatalyzed by octahydro-BINOL derived Broslashnsted acid [221]

78 JacobsenThioureas ProfessorsVachal and Jacobsen iden-tified chiral thioureas (Figure 7) as versatile and effectiveorganocatalysts 1mol of the thiourea was reported to havecatalytic activity in the hydrocyanation (Strecker reaction) ofboth aldimines and ketoimines with very high enantioselec-tivities [222]

Imine hydrophosphonylation particularly effective withelectron-withdrawing ester substituents on the phosphatetook place in the presence of 10mol of the catalyst [223]Mannich reactions of BOC protected imines have also beenreported (Scheme 10) [224] with excellent yields and enan-tioselectivities and show heterocyclic substrate tolerance

A variant of thiourea organocatalyst was found to catalyzethe cyanosilylation of ketones and aldehydes in high yieldsand enantiomeric excesses [225] Thiourea organocatalystwas put to use in the acyl-Pictet-Spengler reaction to formtetrahydro-120573-carbolines [226] The acyl-Mannich reactionproviding a route to enantioenriched heterocycles from

14 Journal of Catalysts

N N N

H H NO H

HO

O

O

O

t-Bu

t-Bu

t-Bu

Figure 7

aromatic starting materials and trichloroethyl chloroformate(TrocCl) is also catalyzed by the thiourea organocatalyst[227] Bifunctional thiourea-base catalyzed double-Michaeladdition of benzofuran-2-ones to dienones is reported forthe synthesis of optically enriched spirocyclic benzofuran-2-ones [228] In another interesting example benzoylthiourea-pyrrolidine catalyst was synthesized and used in the asym-metric Michael addition of ketones to nitroalkenes [229]

Primary amine-thioureas were improvised to catalyzedifficult Michael reactions synthesizing (S)-baclofen (R)-baclofen and (S)-phenibut [230]

79 Cinchona Alkaloids The cinchona alkaloids catalyzemany useful processes with high enantioselectivities Asym-metric phase transfer catalysis (PTC) presents a ldquogreenrdquoalternative to homogeneous synthetic organic chemistrymethodologies Cinchona alkaloids are synthetically mod-ified for their usage in asymmetric PTC O-Alkyl N-arylmethyl derivatives of cinchona alkaloid led highly enantiose-lective alkylation of glycine imines to generate 120572-amino acidderivatives And for the same reaction dimeric cinchonaalkaloid obtained 97ndash99 enantiomeric excess [231 232]Cinchona alkaloids deprotonate substrates with relativelyacidic protons forming a contact ion pair between the result-ing anion and protonated amineThis interaction generates achiral pool around the anion and facilitates enantioselectivereactions with electrophiles The control over the formationof quaternary asymmetric centers is essential to obtain highenantiomeric excesses The 120572-functionalization of ketones(Scheme 11) by the addition of TMSCN to the correspondingcyanohydrin in excellent yield and enantiomeric excess iscatalyzed by the (DHQD)

2AQN catalyst [233]

Increasingly remote stereocenters are being targeted inasymmetric aminocatalysis Organocatalytic allylic amina-tion presents an alternative to the conventional palladiumcatalyzed methodology Amination at the remote 120574-positionusing (DHQ)

2PYR forms highly functionalized amine com-

pounds [234]Bella and Joslashrgensenrsquos reported the first enantioselective

conjugate addition of 120573-diketones to both aromatic andaliphatic alkynones using (DHQ)

2PHAL catalyst [235] Cin-

chona based primary amine catalysis is found to offer high

efficiency and reliability in the asymmetric functionalizationof carbonyl compounds [236 237] Organocatalysts derivedfrom cinchona alkaloids function as Lewis base catalyst inthe cyclizations of allenoates with electron deficient olefinsand imines and emerged as important synthetic tool inthe preparation of biologically active and pharmaceuticallyinteresting cyclic compounds including natural products[238] Recently cinchona thioureas have been reported forthe first time as catalysts in the area of asymmetric oxi-dations [239] Cinchona and cinchonidine derived catalystsperform asymmetric direct aldol reaction of pyruvic aldehydedimethyl acetal with isatin derivatives [240] Likewise thereare various other examples reported where cinchona or itsvariants are used as organocatalysts for syntheses of variousbiologically important molecules [241ndash246]

710 Maruoka Phase Transfer Catalysts The chiral catalystforms a host-guest complex with the substrate and shuttlesbetween the standard organic solvent and a second phaseexample catalytic enantioselective enolate alkylation [72]As we know chiral quaternary ammonium catalysts can beuseful in asymmetric synthesis Kitamura et al reported C2-symmetric ammonium salts catalyzing monoalkylation ofglycine derived Schiff bases with alkyl halides to synthesize120572-alkyl-120572-amino acids under remarkably low catalyst loadings[247ndash249]

Utilizing the solubility of aqueous quaternary ammoniumsalts into organic solvents professor Maruoka developedspirotype chiral ammonium salt with two binaphthyl ringsas a novel chiral phase transfer catalyst Figure 8 depicts theorganocatalyst for direct asymmetric aldol reaction of 120573-hydroxy-120572-amino acid derivative

711 Oxazaborolidines Chiral oxazaborolidines (known asCBS oxazaborolidines after Corey Bakshi and Shibata)catalyze the reduction of prochiral ketones imines andoximes to produce chiral alcohols amines and amino alco-hols respectively in high yields and excellent enantiomericexcesses The chiral Lewis acid generated from o-tolyl-CBS-oxazaborolidine after protonation with trifluoromethanesul-fonimide is very useful in the enantioselective Diels-Alderreaction (Scheme 12) [250ndash256]

Journal of Catalysts 15

O NC OTMSN

OH

N

N

OH

N

OO

2 to 20mol catalyst

TMSCN CHCl3

OC2H5

OC2H5

OC2H5

OC2H5

H3CO

C6H5C6H5

OCH3

Scheme 11 Tian et al [233]

OO

O

OO

II

CH3CH3

CH3

H3C

H3C TIPSOTIPSO

H

H

H

PhPh

NB

minus

+

+

(CF3SO2)2N

20mol catalyst

16hoursDichloromethane minus78∘C

Scheme 12 See [250ndash256]

712 Shi Epoxidation Catalyst Tu et al reported a fructosederived ketone in efficient asymmetric epoxidation of trans-olefins (Scheme 13) [257] Epoxidation catalyst is able toepoxidize trans-alkenes and certain cis-alkenes with good toexcellent yields and selectivities [258 259] Marigo et alrsquosgroup reported an asymmetric organocatalytic epoxidationof 120572 120573-unsaturated aldehydes with environmentally friendlyoxidant hydrogen peroxide [260]

713 N-Heterocyclic Carbene (NHC) as Organocatalysts

7131 Rovis Catalyst The conjugate addition of an aldehydeto an 120572120573-unsaturated compound (Stetter reaction) is apractical methodology for the construction of 14-dicarbonylcompounds bearing quaternary stereocenters Triazoliumsalt in the presence of a base functions as an N-heterocycliccarbene organocatalyst (Figure 9) in highly enantioselectiveintramolecular Stetter reactions [261 262]

7132 Bode Catalyst Bodersquos studies on NHCs (Figure 10)mainly involve catalytic generation of reactive speciessuch as enolates homoenolates and activated carboxylates

N-Mesityl substituent on an imidazolium or triazoliumNHCprecursor generates highly enantioselective annulations fromsimple starting materials under mild reaction conditions[263 264] In an interesting example the catalysts facilitatehighly enantioselective cyclopentene forming annulations ofsimple enals and activated enones [265] Redox esterificationsand amidations of 120572-functionalized aldehydes using achiralcatalyst are also reported [266] Uniting unique activationmodes of N-heterocyclic carbene (NHC) catalysts with theconcept of domino reactions a new fast-growing field cameinto the spotlight in last couple of years or so [267ndash269]

Domino Michaelaldol reaction between 2-mercapto-quinoline-3-carbaldehydes and enals was catalyzed by di-phenylprolinol silyl ether producing 2H-thiopyrano[23-b]-quinolines in excellent yields and enantioselectivities [270]Zhao et al reported studies on ldquocooperative NHC andrutheniun redox catalysisrdquo in the oxidative esterificationof aldehydes [271] Blanc et al reported NHC mediatedorganocatalytic one-pot allylstannation to generate syn-diols[272] With enals as starting aldehydes elegant cascadeprocesses have been developed using oxidative carbene catal-ysis [273ndash276] Over the last few years there are examplesreported in literature where various organocatalysts rally

16 Journal of Catalysts

O

Oxone

OO

O

O

OO

R1 R1

R3

R3

R2 R2H2OCH3CN

Scheme 13

F3C

N+

F3C

Brminus

CF3

CF3

Figure 8 See [176]

N

O

N

N

F

F

F

F

F

+BF4minus

Figure 9

domino reactions and attract their application in organicprocesses in industries [174 175 180 181 183]

Apart from the aforementioned organocatalysts thereare other organic systems which upon appropriate acti-vation function as catalysts in useful asymmetric synthe-ses [155ndash157] 12-Dicarbonyl compounds because of theiradjacent multiple reactive centers upon activation act asefficient pronucleophiles in asymmetric organocatalyzed

N

O

NN+

Clminus

Figure 10

sequential or domino transformations including CndashC or CndashN bond formation [277] Cyclopropenone catalyzed con-version of aldoximes and primary amides into nitriles ina one-pot mild reaction widens the scope of the utiliza-tion of cyclopropenones in organic synthesis [278] Thefirst asymmetric organocatalytic synthesis by phosphinecatalyzed [3+2] cycloaddition of allenoates onto fullereneis reported to yield enantiomerically pure carbocyclicfullerene derivatives under mild conditions [279] A new[3+2] cycloadditioncycloreversion strategy for organocat-alytic and thermally allowed carbonyl-olefin metathesis isreported [280] Recently a strong evidence for halogenbond based organocatalysis is reported for the reactionof 1-chloroisochroman with ketene silyl acetals [281] Acidcatalyzed asymmetric acetalizations of aldehydes are alsodescribed [282] beta-Isocupreidine catalyzed the enantios-elective Morita-Baylis-Hillman reaction of maleimides withisatin derivatives to form 3-substituted 3-hydroxyoxindolederivatives [283 284]

Recent advances in asymmetric catalysis resulted in uti-lizing the less discussed electrophilic properties of iminiumtype intermediates in complex annulations of indoles [285286] and also pyridines [287 288] Shibatomi and Narayamadiscussed the catalytic enantioselective 120572-chlorination of car-bonyl compounds and stereospecific substitution reactions ofthe resulting optically active alkyl chlorides [289]

Though there is no relation between the developmentof two different fields of organocatalysis and gold catalysis

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

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[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

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[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

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[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

Journal of Catalysts 11

R

RNR

REthanol rt

N

O

H

N

R R

+

10mol catalyst

R1

R1

R1R2

R3H2N

middotTfOH

Scheme 6

H NH

O

R

trans H N

O

H

RCis

Reactive conformation

Si

O

H

R

H

Ph

O

Ph

HO

SiCl3 Cl3

Scheme 7

Sulzer-Mosse and Alexakis reported chiral amines cat-alyzing asymmetric conjugate addition to nitroolefins andvinyl sulfones via enamine activation [181]

A bifunctional H-bond directing aminocatalytic systemis found to achieve high stereo- and regiocontrol overdienamine mediated hetero-Diels-Alder reaction [183]

Though amine catalysis is constructing a wide varietyof chiral scaffolds in asymmetric synthesis organocatalysiswith amines for nonasymmetric transformations is alsodeveloping very fast [184 185] The [2+2] cycloaddition ofenals with nitroalkenes is catalyzed by a chiral secondaryamine in the presence of an achiral thiourea for the enantio-and diastereoselective synthesis of highly functionalizedcyclobutanes Mechanistically two consecutiveMichael reac-tions proceed through an unprecedented combination ofdienamineiminium activation mode [186] The reactionengineering of dienamine catalysis for single-step synthesesof highly functionalized molecules such as natural productsor bioactive compounds is reviewed in literature [187]

Chin and coworkers have recently reported some pre-liminary theoretical and experimental studies for convertinga parent diamine into other chiral vicinal diamines Thesediamines can be handy as ligands for chiral catalysts or theycanmake chiral heterocyclic rings and betalactams [188ndash190]

There are some CndashC bonds forming reactions catalyzed bysuch diamine organocatalysts (Scheme 6) [191]

74 Amides Recently the synthesis of multifunctional or-ganocatalysts easily obtained by the condensation of (S)-proline with 2-aminopyridine 26-diaminopyridine or 2-aminoimidazole is reported These chiral prolinamides pro-moted the aldol condensation between cyclohexanone anddifferent aromatic aldehydes (up to 98ee) and also catalyzedDiels-Alder and Michael reactions [192 193]

Rationally designed pyrazole amides function as Michaeldonors in urea catalyzed asymmetric Michael reactions withexcellent chemical and optical yields [194]

A structure-activity relationship with regard to for-mamides as organocatalysts is exploredThis study highlightsthat the cis-conformation of secondary formamides is thereactive conformation in the allylation of aldehydes withallyltrichlorosilane (Scheme 7) [195]

75 Imidazolidinones A certain class of imidazolidinonecompounds (also called MacMillan imidazolidinone organ-ocatalysts) function as catalysts for many asymmetric organictransformations such as asymmetric Diels-Alder reactions

12 Journal of Catalysts

O

N

O

H

O

Up to 97 ee

OHH

N

NO

H20 mol catalyst

CHCl3 minus30∘C

C2H5O OC2H5

R1

R1

R2

R2

+

middotCF3CO2H

Scheme 8 Ouellet et al [202]

R

R

N

One favoured conformer

High enantioselectivity

R = alkyl

Fe

Figure 5

The original such compound was derived from the chi-ral biomolecule phenylalanine [196 197] The first highlyenantioselective organocatalytic Diels-Alder reaction usinga chiral organocatalyst was reported in MacMillanrsquos pio-neering work where the activated iminium ion formedthrough condensation of the imidazolidinone and an 120572120573-unsaturated aldehyde reacted with various dienes to give[4+2] cycloadducts in excellent yields and enantioselectivi-ties Ahrendt et al reportedmany other asymmetric reactionssuch as the 13-dipolar cycloadditions Friedel-Crafts alky-lations 120572-chlorinations 120572-fluorinations and intramolecularMichael reactions usingMacMillanrsquos organocatalysts [96 150198ndash201]

Ouellet et al also reported the combination of imida-zolidinone organocatalyst and Hantzsch ester to facilitatethe first enantioselective organocatalytic hydride reductionof 120572120573-unsaturated aldehydes (Scheme 8) [202 203] Thisimitated naturersquos stereoselective enzymatic transfer hydro-genation with NADH cofactor

Noncovalent interaction is a structure-reactivity andconformation deciding factor which requires immediateattention for understanding organocatalysis [204] Of specialinterest would be the identifying and understanding of othernoncovalent interactions such as charge transfer [205] pndashp stacking immobilization [206] and adsorption or entrap-ment of organocatalysts in nanomaterials [207]

Homogeneous and HeterogenizedMacMillanrsquos OrganocatalystAn asymmetric Diels-Alder reaction was catalyzed with highefficiency and recyclability by a soluble ldquoself-supportedrdquochiral organosilica polymer with embedded imidazolidinonecatalytic moieties [208]

76 Chiral Phosphoric Acids BINOL derived phosphoricacids catalyze nucleophilic addition reactions to imine sub-strates A direct Pictet-Spengler reaction was reported usinga geminally disubstituted tryptamine organocatalyst to formisoquinolines in excellent yield and enantiomeric excess[209] Phosphoric acid catalyzing the reduction of an iminewith a Hantzsch ester in good enantiomeric excess was firstlyreported by Rueping et al Hoffmann et al reported animprovement to this methodology [210 211]

Storer research group reported a one-pot reductive ami-nation of a range of methyl ketones and aryl amines [212]Reductive amination of 2-butanone over silylated phosphoricacid MacMillan TiPSY catalyst was obtained with goodenantiomeric excess

Zhou and List published on the use of chiral Broslashnstedacid (R)-TRIP for highly enantioselective synthesis of phar-maceutically relevant 3-substituted cyclohexylamines from26-diketones wherein the achiral amine substrate acceleratesthe cascade reaction before getting incorporated into the finalproduct (Scheme 9) [213]

Rowland et al reported VAPOL derived phosphoric acidcatalyzed addition of sulfonamides to BOC protected arylimines and protected aminals in excellent enantioselectivities[214]

The (R)-TRIP catalyzed the aza-Diels-Alder reaction ofaldimines with Danishefskyrsquos diene to yield piperidinonederivatives with high enantioselectivity Addition of aceticacid was found to improve both reactivity and enantiose-lectivity [215] Six chemical bonds five stereogenic centersand three cycles were formed in one-pot four-componentUgitype reaction catalyzed by a chiral BINOLderived phosphoricacid [216] BINAP is one of the earliy commercially appliedligands in industrial catalysis [217] Amicroporous recyclableheterogeneous catalyst offering excellent enantioselectivitywas made from a 111015840-binaphthalene-221015840-diol (binol) derivedphosphoric acid chloride and was found as active as thecorresponding homogeneous catalyst [218]

Journal of Catalysts 13

O

O

Ph

OEt HH

Ph

HN

OEt

i-Pr

i-Pr

i-Pri-Pr

i-Pr

i-Pr

O

OP O

OH

EtO2C CO2Et

CyclohexaneMS 5 A 50∘C

NH2

(R)-TRIP (10mol)

82 dr = 24 1 er = 98 21 22

Scheme 9 Zhou and List [213]

NO

N NHH N

HO

S

N

H R

BocO-PrTBS-O

Pr-O

HN

Boc

5mol catalyst+

t-Bu

t-Bu t-Bu

(2) TFA 2min(1) Toluene minus30∘C 48hr

86ndash98 ee

Scheme 10

HO OH

O O

Figure 6

77 Chiral Diols Huang et al reported on use of TADDOLs(Figure 6) as Broslashnsted acid organocatalysts in highly stereos-elective hetero-Diels-Alder reactions [219]

The 120572-amination of carbonyl compounds has also beenaccomplished by using the 1-naphthyl TADDOL derivative asa Broslashnsted acid organocatalyst [220] McDougal and Schausreported asymmetric Morita-Baylis-Hillman reaction that

is the addition of cyclohexenone to different aldehydescatalyzed by octahydro-BINOL derived Broslashnsted acid [221]

78 JacobsenThioureas ProfessorsVachal and Jacobsen iden-tified chiral thioureas (Figure 7) as versatile and effectiveorganocatalysts 1mol of the thiourea was reported to havecatalytic activity in the hydrocyanation (Strecker reaction) ofboth aldimines and ketoimines with very high enantioselec-tivities [222]

Imine hydrophosphonylation particularly effective withelectron-withdrawing ester substituents on the phosphatetook place in the presence of 10mol of the catalyst [223]Mannich reactions of BOC protected imines have also beenreported (Scheme 10) [224] with excellent yields and enan-tioselectivities and show heterocyclic substrate tolerance

A variant of thiourea organocatalyst was found to catalyzethe cyanosilylation of ketones and aldehydes in high yieldsand enantiomeric excesses [225] Thiourea organocatalystwas put to use in the acyl-Pictet-Spengler reaction to formtetrahydro-120573-carbolines [226] The acyl-Mannich reactionproviding a route to enantioenriched heterocycles from

14 Journal of Catalysts

N N N

H H NO H

HO

O

O

O

t-Bu

t-Bu

t-Bu

Figure 7

aromatic starting materials and trichloroethyl chloroformate(TrocCl) is also catalyzed by the thiourea organocatalyst[227] Bifunctional thiourea-base catalyzed double-Michaeladdition of benzofuran-2-ones to dienones is reported forthe synthesis of optically enriched spirocyclic benzofuran-2-ones [228] In another interesting example benzoylthiourea-pyrrolidine catalyst was synthesized and used in the asym-metric Michael addition of ketones to nitroalkenes [229]

Primary amine-thioureas were improvised to catalyzedifficult Michael reactions synthesizing (S)-baclofen (R)-baclofen and (S)-phenibut [230]

79 Cinchona Alkaloids The cinchona alkaloids catalyzemany useful processes with high enantioselectivities Asym-metric phase transfer catalysis (PTC) presents a ldquogreenrdquoalternative to homogeneous synthetic organic chemistrymethodologies Cinchona alkaloids are synthetically mod-ified for their usage in asymmetric PTC O-Alkyl N-arylmethyl derivatives of cinchona alkaloid led highly enantiose-lective alkylation of glycine imines to generate 120572-amino acidderivatives And for the same reaction dimeric cinchonaalkaloid obtained 97ndash99 enantiomeric excess [231 232]Cinchona alkaloids deprotonate substrates with relativelyacidic protons forming a contact ion pair between the result-ing anion and protonated amineThis interaction generates achiral pool around the anion and facilitates enantioselectivereactions with electrophiles The control over the formationof quaternary asymmetric centers is essential to obtain highenantiomeric excesses The 120572-functionalization of ketones(Scheme 11) by the addition of TMSCN to the correspondingcyanohydrin in excellent yield and enantiomeric excess iscatalyzed by the (DHQD)

2AQN catalyst [233]

Increasingly remote stereocenters are being targeted inasymmetric aminocatalysis Organocatalytic allylic amina-tion presents an alternative to the conventional palladiumcatalyzed methodology Amination at the remote 120574-positionusing (DHQ)

2PYR forms highly functionalized amine com-

pounds [234]Bella and Joslashrgensenrsquos reported the first enantioselective

conjugate addition of 120573-diketones to both aromatic andaliphatic alkynones using (DHQ)

2PHAL catalyst [235] Cin-

chona based primary amine catalysis is found to offer high

efficiency and reliability in the asymmetric functionalizationof carbonyl compounds [236 237] Organocatalysts derivedfrom cinchona alkaloids function as Lewis base catalyst inthe cyclizations of allenoates with electron deficient olefinsand imines and emerged as important synthetic tool inthe preparation of biologically active and pharmaceuticallyinteresting cyclic compounds including natural products[238] Recently cinchona thioureas have been reported forthe first time as catalysts in the area of asymmetric oxi-dations [239] Cinchona and cinchonidine derived catalystsperform asymmetric direct aldol reaction of pyruvic aldehydedimethyl acetal with isatin derivatives [240] Likewise thereare various other examples reported where cinchona or itsvariants are used as organocatalysts for syntheses of variousbiologically important molecules [241ndash246]

710 Maruoka Phase Transfer Catalysts The chiral catalystforms a host-guest complex with the substrate and shuttlesbetween the standard organic solvent and a second phaseexample catalytic enantioselective enolate alkylation [72]As we know chiral quaternary ammonium catalysts can beuseful in asymmetric synthesis Kitamura et al reported C2-symmetric ammonium salts catalyzing monoalkylation ofglycine derived Schiff bases with alkyl halides to synthesize120572-alkyl-120572-amino acids under remarkably low catalyst loadings[247ndash249]

Utilizing the solubility of aqueous quaternary ammoniumsalts into organic solvents professor Maruoka developedspirotype chiral ammonium salt with two binaphthyl ringsas a novel chiral phase transfer catalyst Figure 8 depicts theorganocatalyst for direct asymmetric aldol reaction of 120573-hydroxy-120572-amino acid derivative

711 Oxazaborolidines Chiral oxazaborolidines (known asCBS oxazaborolidines after Corey Bakshi and Shibata)catalyze the reduction of prochiral ketones imines andoximes to produce chiral alcohols amines and amino alco-hols respectively in high yields and excellent enantiomericexcesses The chiral Lewis acid generated from o-tolyl-CBS-oxazaborolidine after protonation with trifluoromethanesul-fonimide is very useful in the enantioselective Diels-Alderreaction (Scheme 12) [250ndash256]

Journal of Catalysts 15

O NC OTMSN

OH

N

N

OH

N

OO

2 to 20mol catalyst

TMSCN CHCl3

OC2H5

OC2H5

OC2H5

OC2H5

H3CO

C6H5C6H5

OCH3

Scheme 11 Tian et al [233]

OO

O

OO

II

CH3CH3

CH3

H3C

H3C TIPSOTIPSO

H

H

H

PhPh

NB

minus

+

+

(CF3SO2)2N

20mol catalyst

16hoursDichloromethane minus78∘C

Scheme 12 See [250ndash256]

712 Shi Epoxidation Catalyst Tu et al reported a fructosederived ketone in efficient asymmetric epoxidation of trans-olefins (Scheme 13) [257] Epoxidation catalyst is able toepoxidize trans-alkenes and certain cis-alkenes with good toexcellent yields and selectivities [258 259] Marigo et alrsquosgroup reported an asymmetric organocatalytic epoxidationof 120572 120573-unsaturated aldehydes with environmentally friendlyoxidant hydrogen peroxide [260]

713 N-Heterocyclic Carbene (NHC) as Organocatalysts

7131 Rovis Catalyst The conjugate addition of an aldehydeto an 120572120573-unsaturated compound (Stetter reaction) is apractical methodology for the construction of 14-dicarbonylcompounds bearing quaternary stereocenters Triazoliumsalt in the presence of a base functions as an N-heterocycliccarbene organocatalyst (Figure 9) in highly enantioselectiveintramolecular Stetter reactions [261 262]

7132 Bode Catalyst Bodersquos studies on NHCs (Figure 10)mainly involve catalytic generation of reactive speciessuch as enolates homoenolates and activated carboxylates

N-Mesityl substituent on an imidazolium or triazoliumNHCprecursor generates highly enantioselective annulations fromsimple starting materials under mild reaction conditions[263 264] In an interesting example the catalysts facilitatehighly enantioselective cyclopentene forming annulations ofsimple enals and activated enones [265] Redox esterificationsand amidations of 120572-functionalized aldehydes using achiralcatalyst are also reported [266] Uniting unique activationmodes of N-heterocyclic carbene (NHC) catalysts with theconcept of domino reactions a new fast-growing field cameinto the spotlight in last couple of years or so [267ndash269]

Domino Michaelaldol reaction between 2-mercapto-quinoline-3-carbaldehydes and enals was catalyzed by di-phenylprolinol silyl ether producing 2H-thiopyrano[23-b]-quinolines in excellent yields and enantioselectivities [270]Zhao et al reported studies on ldquocooperative NHC andrutheniun redox catalysisrdquo in the oxidative esterificationof aldehydes [271] Blanc et al reported NHC mediatedorganocatalytic one-pot allylstannation to generate syn-diols[272] With enals as starting aldehydes elegant cascadeprocesses have been developed using oxidative carbene catal-ysis [273ndash276] Over the last few years there are examplesreported in literature where various organocatalysts rally

16 Journal of Catalysts

O

Oxone

OO

O

O

OO

R1 R1

R3

R3

R2 R2H2OCH3CN

Scheme 13

F3C

N+

F3C

Brminus

CF3

CF3

Figure 8 See [176]

N

O

N

N

F

F

F

F

F

+BF4minus

Figure 9

domino reactions and attract their application in organicprocesses in industries [174 175 180 181 183]

Apart from the aforementioned organocatalysts thereare other organic systems which upon appropriate acti-vation function as catalysts in useful asymmetric synthe-ses [155ndash157] 12-Dicarbonyl compounds because of theiradjacent multiple reactive centers upon activation act asefficient pronucleophiles in asymmetric organocatalyzed

N

O

NN+

Clminus

Figure 10

sequential or domino transformations including CndashC or CndashN bond formation [277] Cyclopropenone catalyzed con-version of aldoximes and primary amides into nitriles ina one-pot mild reaction widens the scope of the utiliza-tion of cyclopropenones in organic synthesis [278] Thefirst asymmetric organocatalytic synthesis by phosphinecatalyzed [3+2] cycloaddition of allenoates onto fullereneis reported to yield enantiomerically pure carbocyclicfullerene derivatives under mild conditions [279] A new[3+2] cycloadditioncycloreversion strategy for organocat-alytic and thermally allowed carbonyl-olefin metathesis isreported [280] Recently a strong evidence for halogenbond based organocatalysis is reported for the reactionof 1-chloroisochroman with ketene silyl acetals [281] Acidcatalyzed asymmetric acetalizations of aldehydes are alsodescribed [282] beta-Isocupreidine catalyzed the enantios-elective Morita-Baylis-Hillman reaction of maleimides withisatin derivatives to form 3-substituted 3-hydroxyoxindolederivatives [283 284]

Recent advances in asymmetric catalysis resulted in uti-lizing the less discussed electrophilic properties of iminiumtype intermediates in complex annulations of indoles [285286] and also pyridines [287 288] Shibatomi and Narayamadiscussed the catalytic enantioselective 120572-chlorination of car-bonyl compounds and stereospecific substitution reactions ofthe resulting optically active alkyl chlorides [289]

Though there is no relation between the developmentof two different fields of organocatalysis and gold catalysis

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

[1] ldquoOur Common Future Report of the World Commissionon Environment and Development United Nations (UN)Commission on Environment and Development (BrundtlandCommission) 1987rdquo Published as Annex to General Assem-bly document A42427 Development and International Co-operation Environment August 1987

[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

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[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

[17] J R Anderson and K C Pratt Introduction To Characterisationand Testing of Catalysts Academic Press Sydney Australia1985

[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

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Analytical Methods in Chemistry

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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

12 Journal of Catalysts

O

N

O

H

O

Up to 97 ee

OHH

N

NO

H20 mol catalyst

CHCl3 minus30∘C

C2H5O OC2H5

R1

R1

R2

R2

+

middotCF3CO2H

Scheme 8 Ouellet et al [202]

R

R

N

One favoured conformer

High enantioselectivity

R = alkyl

Fe

Figure 5

The original such compound was derived from the chi-ral biomolecule phenylalanine [196 197] The first highlyenantioselective organocatalytic Diels-Alder reaction usinga chiral organocatalyst was reported in MacMillanrsquos pio-neering work where the activated iminium ion formedthrough condensation of the imidazolidinone and an 120572120573-unsaturated aldehyde reacted with various dienes to give[4+2] cycloadducts in excellent yields and enantioselectivi-ties Ahrendt et al reportedmany other asymmetric reactionssuch as the 13-dipolar cycloadditions Friedel-Crafts alky-lations 120572-chlorinations 120572-fluorinations and intramolecularMichael reactions usingMacMillanrsquos organocatalysts [96 150198ndash201]

Ouellet et al also reported the combination of imida-zolidinone organocatalyst and Hantzsch ester to facilitatethe first enantioselective organocatalytic hydride reductionof 120572120573-unsaturated aldehydes (Scheme 8) [202 203] Thisimitated naturersquos stereoselective enzymatic transfer hydro-genation with NADH cofactor

Noncovalent interaction is a structure-reactivity andconformation deciding factor which requires immediateattention for understanding organocatalysis [204] Of specialinterest would be the identifying and understanding of othernoncovalent interactions such as charge transfer [205] pndashp stacking immobilization [206] and adsorption or entrap-ment of organocatalysts in nanomaterials [207]

Homogeneous and HeterogenizedMacMillanrsquos OrganocatalystAn asymmetric Diels-Alder reaction was catalyzed with highefficiency and recyclability by a soluble ldquoself-supportedrdquochiral organosilica polymer with embedded imidazolidinonecatalytic moieties [208]

76 Chiral Phosphoric Acids BINOL derived phosphoricacids catalyze nucleophilic addition reactions to imine sub-strates A direct Pictet-Spengler reaction was reported usinga geminally disubstituted tryptamine organocatalyst to formisoquinolines in excellent yield and enantiomeric excess[209] Phosphoric acid catalyzing the reduction of an iminewith a Hantzsch ester in good enantiomeric excess was firstlyreported by Rueping et al Hoffmann et al reported animprovement to this methodology [210 211]

Storer research group reported a one-pot reductive ami-nation of a range of methyl ketones and aryl amines [212]Reductive amination of 2-butanone over silylated phosphoricacid MacMillan TiPSY catalyst was obtained with goodenantiomeric excess

Zhou and List published on the use of chiral Broslashnstedacid (R)-TRIP for highly enantioselective synthesis of phar-maceutically relevant 3-substituted cyclohexylamines from26-diketones wherein the achiral amine substrate acceleratesthe cascade reaction before getting incorporated into the finalproduct (Scheme 9) [213]

Rowland et al reported VAPOL derived phosphoric acidcatalyzed addition of sulfonamides to BOC protected arylimines and protected aminals in excellent enantioselectivities[214]

The (R)-TRIP catalyzed the aza-Diels-Alder reaction ofaldimines with Danishefskyrsquos diene to yield piperidinonederivatives with high enantioselectivity Addition of aceticacid was found to improve both reactivity and enantiose-lectivity [215] Six chemical bonds five stereogenic centersand three cycles were formed in one-pot four-componentUgitype reaction catalyzed by a chiral BINOLderived phosphoricacid [216] BINAP is one of the earliy commercially appliedligands in industrial catalysis [217] Amicroporous recyclableheterogeneous catalyst offering excellent enantioselectivitywas made from a 111015840-binaphthalene-221015840-diol (binol) derivedphosphoric acid chloride and was found as active as thecorresponding homogeneous catalyst [218]

Journal of Catalysts 13

O

O

Ph

OEt HH

Ph

HN

OEt

i-Pr

i-Pr

i-Pri-Pr

i-Pr

i-Pr

O

OP O

OH

EtO2C CO2Et

CyclohexaneMS 5 A 50∘C

NH2

(R)-TRIP (10mol)

82 dr = 24 1 er = 98 21 22

Scheme 9 Zhou and List [213]

NO

N NHH N

HO

S

N

H R

BocO-PrTBS-O

Pr-O

HN

Boc

5mol catalyst+

t-Bu

t-Bu t-Bu

(2) TFA 2min(1) Toluene minus30∘C 48hr

86ndash98 ee

Scheme 10

HO OH

O O

Figure 6

77 Chiral Diols Huang et al reported on use of TADDOLs(Figure 6) as Broslashnsted acid organocatalysts in highly stereos-elective hetero-Diels-Alder reactions [219]

The 120572-amination of carbonyl compounds has also beenaccomplished by using the 1-naphthyl TADDOL derivative asa Broslashnsted acid organocatalyst [220] McDougal and Schausreported asymmetric Morita-Baylis-Hillman reaction that

is the addition of cyclohexenone to different aldehydescatalyzed by octahydro-BINOL derived Broslashnsted acid [221]

78 JacobsenThioureas ProfessorsVachal and Jacobsen iden-tified chiral thioureas (Figure 7) as versatile and effectiveorganocatalysts 1mol of the thiourea was reported to havecatalytic activity in the hydrocyanation (Strecker reaction) ofboth aldimines and ketoimines with very high enantioselec-tivities [222]

Imine hydrophosphonylation particularly effective withelectron-withdrawing ester substituents on the phosphatetook place in the presence of 10mol of the catalyst [223]Mannich reactions of BOC protected imines have also beenreported (Scheme 10) [224] with excellent yields and enan-tioselectivities and show heterocyclic substrate tolerance

A variant of thiourea organocatalyst was found to catalyzethe cyanosilylation of ketones and aldehydes in high yieldsand enantiomeric excesses [225] Thiourea organocatalystwas put to use in the acyl-Pictet-Spengler reaction to formtetrahydro-120573-carbolines [226] The acyl-Mannich reactionproviding a route to enantioenriched heterocycles from

14 Journal of Catalysts

N N N

H H NO H

HO

O

O

O

t-Bu

t-Bu

t-Bu

Figure 7

aromatic starting materials and trichloroethyl chloroformate(TrocCl) is also catalyzed by the thiourea organocatalyst[227] Bifunctional thiourea-base catalyzed double-Michaeladdition of benzofuran-2-ones to dienones is reported forthe synthesis of optically enriched spirocyclic benzofuran-2-ones [228] In another interesting example benzoylthiourea-pyrrolidine catalyst was synthesized and used in the asym-metric Michael addition of ketones to nitroalkenes [229]

Primary amine-thioureas were improvised to catalyzedifficult Michael reactions synthesizing (S)-baclofen (R)-baclofen and (S)-phenibut [230]

79 Cinchona Alkaloids The cinchona alkaloids catalyzemany useful processes with high enantioselectivities Asym-metric phase transfer catalysis (PTC) presents a ldquogreenrdquoalternative to homogeneous synthetic organic chemistrymethodologies Cinchona alkaloids are synthetically mod-ified for their usage in asymmetric PTC O-Alkyl N-arylmethyl derivatives of cinchona alkaloid led highly enantiose-lective alkylation of glycine imines to generate 120572-amino acidderivatives And for the same reaction dimeric cinchonaalkaloid obtained 97ndash99 enantiomeric excess [231 232]Cinchona alkaloids deprotonate substrates with relativelyacidic protons forming a contact ion pair between the result-ing anion and protonated amineThis interaction generates achiral pool around the anion and facilitates enantioselectivereactions with electrophiles The control over the formationof quaternary asymmetric centers is essential to obtain highenantiomeric excesses The 120572-functionalization of ketones(Scheme 11) by the addition of TMSCN to the correspondingcyanohydrin in excellent yield and enantiomeric excess iscatalyzed by the (DHQD)

2AQN catalyst [233]

Increasingly remote stereocenters are being targeted inasymmetric aminocatalysis Organocatalytic allylic amina-tion presents an alternative to the conventional palladiumcatalyzed methodology Amination at the remote 120574-positionusing (DHQ)

2PYR forms highly functionalized amine com-

pounds [234]Bella and Joslashrgensenrsquos reported the first enantioselective

conjugate addition of 120573-diketones to both aromatic andaliphatic alkynones using (DHQ)

2PHAL catalyst [235] Cin-

chona based primary amine catalysis is found to offer high

efficiency and reliability in the asymmetric functionalizationof carbonyl compounds [236 237] Organocatalysts derivedfrom cinchona alkaloids function as Lewis base catalyst inthe cyclizations of allenoates with electron deficient olefinsand imines and emerged as important synthetic tool inthe preparation of biologically active and pharmaceuticallyinteresting cyclic compounds including natural products[238] Recently cinchona thioureas have been reported forthe first time as catalysts in the area of asymmetric oxi-dations [239] Cinchona and cinchonidine derived catalystsperform asymmetric direct aldol reaction of pyruvic aldehydedimethyl acetal with isatin derivatives [240] Likewise thereare various other examples reported where cinchona or itsvariants are used as organocatalysts for syntheses of variousbiologically important molecules [241ndash246]

710 Maruoka Phase Transfer Catalysts The chiral catalystforms a host-guest complex with the substrate and shuttlesbetween the standard organic solvent and a second phaseexample catalytic enantioselective enolate alkylation [72]As we know chiral quaternary ammonium catalysts can beuseful in asymmetric synthesis Kitamura et al reported C2-symmetric ammonium salts catalyzing monoalkylation ofglycine derived Schiff bases with alkyl halides to synthesize120572-alkyl-120572-amino acids under remarkably low catalyst loadings[247ndash249]

Utilizing the solubility of aqueous quaternary ammoniumsalts into organic solvents professor Maruoka developedspirotype chiral ammonium salt with two binaphthyl ringsas a novel chiral phase transfer catalyst Figure 8 depicts theorganocatalyst for direct asymmetric aldol reaction of 120573-hydroxy-120572-amino acid derivative

711 Oxazaborolidines Chiral oxazaborolidines (known asCBS oxazaborolidines after Corey Bakshi and Shibata)catalyze the reduction of prochiral ketones imines andoximes to produce chiral alcohols amines and amino alco-hols respectively in high yields and excellent enantiomericexcesses The chiral Lewis acid generated from o-tolyl-CBS-oxazaborolidine after protonation with trifluoromethanesul-fonimide is very useful in the enantioselective Diels-Alderreaction (Scheme 12) [250ndash256]

Journal of Catalysts 15

O NC OTMSN

OH

N

N

OH

N

OO

2 to 20mol catalyst

TMSCN CHCl3

OC2H5

OC2H5

OC2H5

OC2H5

H3CO

C6H5C6H5

OCH3

Scheme 11 Tian et al [233]

OO

O

OO

II

CH3CH3

CH3

H3C

H3C TIPSOTIPSO

H

H

H

PhPh

NB

minus

+

+

(CF3SO2)2N

20mol catalyst

16hoursDichloromethane minus78∘C

Scheme 12 See [250ndash256]

712 Shi Epoxidation Catalyst Tu et al reported a fructosederived ketone in efficient asymmetric epoxidation of trans-olefins (Scheme 13) [257] Epoxidation catalyst is able toepoxidize trans-alkenes and certain cis-alkenes with good toexcellent yields and selectivities [258 259] Marigo et alrsquosgroup reported an asymmetric organocatalytic epoxidationof 120572 120573-unsaturated aldehydes with environmentally friendlyoxidant hydrogen peroxide [260]

713 N-Heterocyclic Carbene (NHC) as Organocatalysts

7131 Rovis Catalyst The conjugate addition of an aldehydeto an 120572120573-unsaturated compound (Stetter reaction) is apractical methodology for the construction of 14-dicarbonylcompounds bearing quaternary stereocenters Triazoliumsalt in the presence of a base functions as an N-heterocycliccarbene organocatalyst (Figure 9) in highly enantioselectiveintramolecular Stetter reactions [261 262]

7132 Bode Catalyst Bodersquos studies on NHCs (Figure 10)mainly involve catalytic generation of reactive speciessuch as enolates homoenolates and activated carboxylates

N-Mesityl substituent on an imidazolium or triazoliumNHCprecursor generates highly enantioselective annulations fromsimple starting materials under mild reaction conditions[263 264] In an interesting example the catalysts facilitatehighly enantioselective cyclopentene forming annulations ofsimple enals and activated enones [265] Redox esterificationsand amidations of 120572-functionalized aldehydes using achiralcatalyst are also reported [266] Uniting unique activationmodes of N-heterocyclic carbene (NHC) catalysts with theconcept of domino reactions a new fast-growing field cameinto the spotlight in last couple of years or so [267ndash269]

Domino Michaelaldol reaction between 2-mercapto-quinoline-3-carbaldehydes and enals was catalyzed by di-phenylprolinol silyl ether producing 2H-thiopyrano[23-b]-quinolines in excellent yields and enantioselectivities [270]Zhao et al reported studies on ldquocooperative NHC andrutheniun redox catalysisrdquo in the oxidative esterificationof aldehydes [271] Blanc et al reported NHC mediatedorganocatalytic one-pot allylstannation to generate syn-diols[272] With enals as starting aldehydes elegant cascadeprocesses have been developed using oxidative carbene catal-ysis [273ndash276] Over the last few years there are examplesreported in literature where various organocatalysts rally

16 Journal of Catalysts

O

Oxone

OO

O

O

OO

R1 R1

R3

R3

R2 R2H2OCH3CN

Scheme 13

F3C

N+

F3C

Brminus

CF3

CF3

Figure 8 See [176]

N

O

N

N

F

F

F

F

F

+BF4minus

Figure 9

domino reactions and attract their application in organicprocesses in industries [174 175 180 181 183]

Apart from the aforementioned organocatalysts thereare other organic systems which upon appropriate acti-vation function as catalysts in useful asymmetric synthe-ses [155ndash157] 12-Dicarbonyl compounds because of theiradjacent multiple reactive centers upon activation act asefficient pronucleophiles in asymmetric organocatalyzed

N

O

NN+

Clminus

Figure 10

sequential or domino transformations including CndashC or CndashN bond formation [277] Cyclopropenone catalyzed con-version of aldoximes and primary amides into nitriles ina one-pot mild reaction widens the scope of the utiliza-tion of cyclopropenones in organic synthesis [278] Thefirst asymmetric organocatalytic synthesis by phosphinecatalyzed [3+2] cycloaddition of allenoates onto fullereneis reported to yield enantiomerically pure carbocyclicfullerene derivatives under mild conditions [279] A new[3+2] cycloadditioncycloreversion strategy for organocat-alytic and thermally allowed carbonyl-olefin metathesis isreported [280] Recently a strong evidence for halogenbond based organocatalysis is reported for the reactionof 1-chloroisochroman with ketene silyl acetals [281] Acidcatalyzed asymmetric acetalizations of aldehydes are alsodescribed [282] beta-Isocupreidine catalyzed the enantios-elective Morita-Baylis-Hillman reaction of maleimides withisatin derivatives to form 3-substituted 3-hydroxyoxindolederivatives [283 284]

Recent advances in asymmetric catalysis resulted in uti-lizing the less discussed electrophilic properties of iminiumtype intermediates in complex annulations of indoles [285286] and also pyridines [287 288] Shibatomi and Narayamadiscussed the catalytic enantioselective 120572-chlorination of car-bonyl compounds and stereospecific substitution reactions ofthe resulting optically active alkyl chlorides [289]

Though there is no relation between the developmentof two different fields of organocatalysis and gold catalysis

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

[1] ldquoOur Common Future Report of the World Commissionon Environment and Development United Nations (UN)Commission on Environment and Development (BrundtlandCommission) 1987rdquo Published as Annex to General Assem-bly document A42427 Development and International Co-operation Environment August 1987

[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

[17] J R Anderson and K C Pratt Introduction To Characterisationand Testing of Catalysts Academic Press Sydney Australia1985

[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

Journal of Catalysts 13

O

O

Ph

OEt HH

Ph

HN

OEt

i-Pr

i-Pr

i-Pri-Pr

i-Pr

i-Pr

O

OP O

OH

EtO2C CO2Et

CyclohexaneMS 5 A 50∘C

NH2

(R)-TRIP (10mol)

82 dr = 24 1 er = 98 21 22

Scheme 9 Zhou and List [213]

NO

N NHH N

HO

S

N

H R

BocO-PrTBS-O

Pr-O

HN

Boc

5mol catalyst+

t-Bu

t-Bu t-Bu

(2) TFA 2min(1) Toluene minus30∘C 48hr

86ndash98 ee

Scheme 10

HO OH

O O

Figure 6

77 Chiral Diols Huang et al reported on use of TADDOLs(Figure 6) as Broslashnsted acid organocatalysts in highly stereos-elective hetero-Diels-Alder reactions [219]

The 120572-amination of carbonyl compounds has also beenaccomplished by using the 1-naphthyl TADDOL derivative asa Broslashnsted acid organocatalyst [220] McDougal and Schausreported asymmetric Morita-Baylis-Hillman reaction that

is the addition of cyclohexenone to different aldehydescatalyzed by octahydro-BINOL derived Broslashnsted acid [221]

78 JacobsenThioureas ProfessorsVachal and Jacobsen iden-tified chiral thioureas (Figure 7) as versatile and effectiveorganocatalysts 1mol of the thiourea was reported to havecatalytic activity in the hydrocyanation (Strecker reaction) ofboth aldimines and ketoimines with very high enantioselec-tivities [222]

Imine hydrophosphonylation particularly effective withelectron-withdrawing ester substituents on the phosphatetook place in the presence of 10mol of the catalyst [223]Mannich reactions of BOC protected imines have also beenreported (Scheme 10) [224] with excellent yields and enan-tioselectivities and show heterocyclic substrate tolerance

A variant of thiourea organocatalyst was found to catalyzethe cyanosilylation of ketones and aldehydes in high yieldsand enantiomeric excesses [225] Thiourea organocatalystwas put to use in the acyl-Pictet-Spengler reaction to formtetrahydro-120573-carbolines [226] The acyl-Mannich reactionproviding a route to enantioenriched heterocycles from

14 Journal of Catalysts

N N N

H H NO H

HO

O

O

O

t-Bu

t-Bu

t-Bu

Figure 7

aromatic starting materials and trichloroethyl chloroformate(TrocCl) is also catalyzed by the thiourea organocatalyst[227] Bifunctional thiourea-base catalyzed double-Michaeladdition of benzofuran-2-ones to dienones is reported forthe synthesis of optically enriched spirocyclic benzofuran-2-ones [228] In another interesting example benzoylthiourea-pyrrolidine catalyst was synthesized and used in the asym-metric Michael addition of ketones to nitroalkenes [229]

Primary amine-thioureas were improvised to catalyzedifficult Michael reactions synthesizing (S)-baclofen (R)-baclofen and (S)-phenibut [230]

79 Cinchona Alkaloids The cinchona alkaloids catalyzemany useful processes with high enantioselectivities Asym-metric phase transfer catalysis (PTC) presents a ldquogreenrdquoalternative to homogeneous synthetic organic chemistrymethodologies Cinchona alkaloids are synthetically mod-ified for their usage in asymmetric PTC O-Alkyl N-arylmethyl derivatives of cinchona alkaloid led highly enantiose-lective alkylation of glycine imines to generate 120572-amino acidderivatives And for the same reaction dimeric cinchonaalkaloid obtained 97ndash99 enantiomeric excess [231 232]Cinchona alkaloids deprotonate substrates with relativelyacidic protons forming a contact ion pair between the result-ing anion and protonated amineThis interaction generates achiral pool around the anion and facilitates enantioselectivereactions with electrophiles The control over the formationof quaternary asymmetric centers is essential to obtain highenantiomeric excesses The 120572-functionalization of ketones(Scheme 11) by the addition of TMSCN to the correspondingcyanohydrin in excellent yield and enantiomeric excess iscatalyzed by the (DHQD)

2AQN catalyst [233]

Increasingly remote stereocenters are being targeted inasymmetric aminocatalysis Organocatalytic allylic amina-tion presents an alternative to the conventional palladiumcatalyzed methodology Amination at the remote 120574-positionusing (DHQ)

2PYR forms highly functionalized amine com-

pounds [234]Bella and Joslashrgensenrsquos reported the first enantioselective

conjugate addition of 120573-diketones to both aromatic andaliphatic alkynones using (DHQ)

2PHAL catalyst [235] Cin-

chona based primary amine catalysis is found to offer high

efficiency and reliability in the asymmetric functionalizationof carbonyl compounds [236 237] Organocatalysts derivedfrom cinchona alkaloids function as Lewis base catalyst inthe cyclizations of allenoates with electron deficient olefinsand imines and emerged as important synthetic tool inthe preparation of biologically active and pharmaceuticallyinteresting cyclic compounds including natural products[238] Recently cinchona thioureas have been reported forthe first time as catalysts in the area of asymmetric oxi-dations [239] Cinchona and cinchonidine derived catalystsperform asymmetric direct aldol reaction of pyruvic aldehydedimethyl acetal with isatin derivatives [240] Likewise thereare various other examples reported where cinchona or itsvariants are used as organocatalysts for syntheses of variousbiologically important molecules [241ndash246]

710 Maruoka Phase Transfer Catalysts The chiral catalystforms a host-guest complex with the substrate and shuttlesbetween the standard organic solvent and a second phaseexample catalytic enantioselective enolate alkylation [72]As we know chiral quaternary ammonium catalysts can beuseful in asymmetric synthesis Kitamura et al reported C2-symmetric ammonium salts catalyzing monoalkylation ofglycine derived Schiff bases with alkyl halides to synthesize120572-alkyl-120572-amino acids under remarkably low catalyst loadings[247ndash249]

Utilizing the solubility of aqueous quaternary ammoniumsalts into organic solvents professor Maruoka developedspirotype chiral ammonium salt with two binaphthyl ringsas a novel chiral phase transfer catalyst Figure 8 depicts theorganocatalyst for direct asymmetric aldol reaction of 120573-hydroxy-120572-amino acid derivative

711 Oxazaborolidines Chiral oxazaborolidines (known asCBS oxazaborolidines after Corey Bakshi and Shibata)catalyze the reduction of prochiral ketones imines andoximes to produce chiral alcohols amines and amino alco-hols respectively in high yields and excellent enantiomericexcesses The chiral Lewis acid generated from o-tolyl-CBS-oxazaborolidine after protonation with trifluoromethanesul-fonimide is very useful in the enantioselective Diels-Alderreaction (Scheme 12) [250ndash256]

Journal of Catalysts 15

O NC OTMSN

OH

N

N

OH

N

OO

2 to 20mol catalyst

TMSCN CHCl3

OC2H5

OC2H5

OC2H5

OC2H5

H3CO

C6H5C6H5

OCH3

Scheme 11 Tian et al [233]

OO

O

OO

II

CH3CH3

CH3

H3C

H3C TIPSOTIPSO

H

H

H

PhPh

NB

minus

+

+

(CF3SO2)2N

20mol catalyst

16hoursDichloromethane minus78∘C

Scheme 12 See [250ndash256]

712 Shi Epoxidation Catalyst Tu et al reported a fructosederived ketone in efficient asymmetric epoxidation of trans-olefins (Scheme 13) [257] Epoxidation catalyst is able toepoxidize trans-alkenes and certain cis-alkenes with good toexcellent yields and selectivities [258 259] Marigo et alrsquosgroup reported an asymmetric organocatalytic epoxidationof 120572 120573-unsaturated aldehydes with environmentally friendlyoxidant hydrogen peroxide [260]

713 N-Heterocyclic Carbene (NHC) as Organocatalysts

7131 Rovis Catalyst The conjugate addition of an aldehydeto an 120572120573-unsaturated compound (Stetter reaction) is apractical methodology for the construction of 14-dicarbonylcompounds bearing quaternary stereocenters Triazoliumsalt in the presence of a base functions as an N-heterocycliccarbene organocatalyst (Figure 9) in highly enantioselectiveintramolecular Stetter reactions [261 262]

7132 Bode Catalyst Bodersquos studies on NHCs (Figure 10)mainly involve catalytic generation of reactive speciessuch as enolates homoenolates and activated carboxylates

N-Mesityl substituent on an imidazolium or triazoliumNHCprecursor generates highly enantioselective annulations fromsimple starting materials under mild reaction conditions[263 264] In an interesting example the catalysts facilitatehighly enantioselective cyclopentene forming annulations ofsimple enals and activated enones [265] Redox esterificationsand amidations of 120572-functionalized aldehydes using achiralcatalyst are also reported [266] Uniting unique activationmodes of N-heterocyclic carbene (NHC) catalysts with theconcept of domino reactions a new fast-growing field cameinto the spotlight in last couple of years or so [267ndash269]

Domino Michaelaldol reaction between 2-mercapto-quinoline-3-carbaldehydes and enals was catalyzed by di-phenylprolinol silyl ether producing 2H-thiopyrano[23-b]-quinolines in excellent yields and enantioselectivities [270]Zhao et al reported studies on ldquocooperative NHC andrutheniun redox catalysisrdquo in the oxidative esterificationof aldehydes [271] Blanc et al reported NHC mediatedorganocatalytic one-pot allylstannation to generate syn-diols[272] With enals as starting aldehydes elegant cascadeprocesses have been developed using oxidative carbene catal-ysis [273ndash276] Over the last few years there are examplesreported in literature where various organocatalysts rally

16 Journal of Catalysts

O

Oxone

OO

O

O

OO

R1 R1

R3

R3

R2 R2H2OCH3CN

Scheme 13

F3C

N+

F3C

Brminus

CF3

CF3

Figure 8 See [176]

N

O

N

N

F

F

F

F

F

+BF4minus

Figure 9

domino reactions and attract their application in organicprocesses in industries [174 175 180 181 183]

Apart from the aforementioned organocatalysts thereare other organic systems which upon appropriate acti-vation function as catalysts in useful asymmetric synthe-ses [155ndash157] 12-Dicarbonyl compounds because of theiradjacent multiple reactive centers upon activation act asefficient pronucleophiles in asymmetric organocatalyzed

N

O

NN+

Clminus

Figure 10

sequential or domino transformations including CndashC or CndashN bond formation [277] Cyclopropenone catalyzed con-version of aldoximes and primary amides into nitriles ina one-pot mild reaction widens the scope of the utiliza-tion of cyclopropenones in organic synthesis [278] Thefirst asymmetric organocatalytic synthesis by phosphinecatalyzed [3+2] cycloaddition of allenoates onto fullereneis reported to yield enantiomerically pure carbocyclicfullerene derivatives under mild conditions [279] A new[3+2] cycloadditioncycloreversion strategy for organocat-alytic and thermally allowed carbonyl-olefin metathesis isreported [280] Recently a strong evidence for halogenbond based organocatalysis is reported for the reactionof 1-chloroisochroman with ketene silyl acetals [281] Acidcatalyzed asymmetric acetalizations of aldehydes are alsodescribed [282] beta-Isocupreidine catalyzed the enantios-elective Morita-Baylis-Hillman reaction of maleimides withisatin derivatives to form 3-substituted 3-hydroxyoxindolederivatives [283 284]

Recent advances in asymmetric catalysis resulted in uti-lizing the less discussed electrophilic properties of iminiumtype intermediates in complex annulations of indoles [285286] and also pyridines [287 288] Shibatomi and Narayamadiscussed the catalytic enantioselective 120572-chlorination of car-bonyl compounds and stereospecific substitution reactions ofthe resulting optically active alkyl chlorides [289]

Though there is no relation between the developmentof two different fields of organocatalysis and gold catalysis

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

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[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

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[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

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[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

14 Journal of Catalysts

N N N

H H NO H

HO

O

O

O

t-Bu

t-Bu

t-Bu

Figure 7

aromatic starting materials and trichloroethyl chloroformate(TrocCl) is also catalyzed by the thiourea organocatalyst[227] Bifunctional thiourea-base catalyzed double-Michaeladdition of benzofuran-2-ones to dienones is reported forthe synthesis of optically enriched spirocyclic benzofuran-2-ones [228] In another interesting example benzoylthiourea-pyrrolidine catalyst was synthesized and used in the asym-metric Michael addition of ketones to nitroalkenes [229]

Primary amine-thioureas were improvised to catalyzedifficult Michael reactions synthesizing (S)-baclofen (R)-baclofen and (S)-phenibut [230]

79 Cinchona Alkaloids The cinchona alkaloids catalyzemany useful processes with high enantioselectivities Asym-metric phase transfer catalysis (PTC) presents a ldquogreenrdquoalternative to homogeneous synthetic organic chemistrymethodologies Cinchona alkaloids are synthetically mod-ified for their usage in asymmetric PTC O-Alkyl N-arylmethyl derivatives of cinchona alkaloid led highly enantiose-lective alkylation of glycine imines to generate 120572-amino acidderivatives And for the same reaction dimeric cinchonaalkaloid obtained 97ndash99 enantiomeric excess [231 232]Cinchona alkaloids deprotonate substrates with relativelyacidic protons forming a contact ion pair between the result-ing anion and protonated amineThis interaction generates achiral pool around the anion and facilitates enantioselectivereactions with electrophiles The control over the formationof quaternary asymmetric centers is essential to obtain highenantiomeric excesses The 120572-functionalization of ketones(Scheme 11) by the addition of TMSCN to the correspondingcyanohydrin in excellent yield and enantiomeric excess iscatalyzed by the (DHQD)

2AQN catalyst [233]

Increasingly remote stereocenters are being targeted inasymmetric aminocatalysis Organocatalytic allylic amina-tion presents an alternative to the conventional palladiumcatalyzed methodology Amination at the remote 120574-positionusing (DHQ)

2PYR forms highly functionalized amine com-

pounds [234]Bella and Joslashrgensenrsquos reported the first enantioselective

conjugate addition of 120573-diketones to both aromatic andaliphatic alkynones using (DHQ)

2PHAL catalyst [235] Cin-

chona based primary amine catalysis is found to offer high

efficiency and reliability in the asymmetric functionalizationof carbonyl compounds [236 237] Organocatalysts derivedfrom cinchona alkaloids function as Lewis base catalyst inthe cyclizations of allenoates with electron deficient olefinsand imines and emerged as important synthetic tool inthe preparation of biologically active and pharmaceuticallyinteresting cyclic compounds including natural products[238] Recently cinchona thioureas have been reported forthe first time as catalysts in the area of asymmetric oxi-dations [239] Cinchona and cinchonidine derived catalystsperform asymmetric direct aldol reaction of pyruvic aldehydedimethyl acetal with isatin derivatives [240] Likewise thereare various other examples reported where cinchona or itsvariants are used as organocatalysts for syntheses of variousbiologically important molecules [241ndash246]

710 Maruoka Phase Transfer Catalysts The chiral catalystforms a host-guest complex with the substrate and shuttlesbetween the standard organic solvent and a second phaseexample catalytic enantioselective enolate alkylation [72]As we know chiral quaternary ammonium catalysts can beuseful in asymmetric synthesis Kitamura et al reported C2-symmetric ammonium salts catalyzing monoalkylation ofglycine derived Schiff bases with alkyl halides to synthesize120572-alkyl-120572-amino acids under remarkably low catalyst loadings[247ndash249]

Utilizing the solubility of aqueous quaternary ammoniumsalts into organic solvents professor Maruoka developedspirotype chiral ammonium salt with two binaphthyl ringsas a novel chiral phase transfer catalyst Figure 8 depicts theorganocatalyst for direct asymmetric aldol reaction of 120573-hydroxy-120572-amino acid derivative

711 Oxazaborolidines Chiral oxazaborolidines (known asCBS oxazaborolidines after Corey Bakshi and Shibata)catalyze the reduction of prochiral ketones imines andoximes to produce chiral alcohols amines and amino alco-hols respectively in high yields and excellent enantiomericexcesses The chiral Lewis acid generated from o-tolyl-CBS-oxazaborolidine after protonation with trifluoromethanesul-fonimide is very useful in the enantioselective Diels-Alderreaction (Scheme 12) [250ndash256]

Journal of Catalysts 15

O NC OTMSN

OH

N

N

OH

N

OO

2 to 20mol catalyst

TMSCN CHCl3

OC2H5

OC2H5

OC2H5

OC2H5

H3CO

C6H5C6H5

OCH3

Scheme 11 Tian et al [233]

OO

O

OO

II

CH3CH3

CH3

H3C

H3C TIPSOTIPSO

H

H

H

PhPh

NB

minus

+

+

(CF3SO2)2N

20mol catalyst

16hoursDichloromethane minus78∘C

Scheme 12 See [250ndash256]

712 Shi Epoxidation Catalyst Tu et al reported a fructosederived ketone in efficient asymmetric epoxidation of trans-olefins (Scheme 13) [257] Epoxidation catalyst is able toepoxidize trans-alkenes and certain cis-alkenes with good toexcellent yields and selectivities [258 259] Marigo et alrsquosgroup reported an asymmetric organocatalytic epoxidationof 120572 120573-unsaturated aldehydes with environmentally friendlyoxidant hydrogen peroxide [260]

713 N-Heterocyclic Carbene (NHC) as Organocatalysts

7131 Rovis Catalyst The conjugate addition of an aldehydeto an 120572120573-unsaturated compound (Stetter reaction) is apractical methodology for the construction of 14-dicarbonylcompounds bearing quaternary stereocenters Triazoliumsalt in the presence of a base functions as an N-heterocycliccarbene organocatalyst (Figure 9) in highly enantioselectiveintramolecular Stetter reactions [261 262]

7132 Bode Catalyst Bodersquos studies on NHCs (Figure 10)mainly involve catalytic generation of reactive speciessuch as enolates homoenolates and activated carboxylates

N-Mesityl substituent on an imidazolium or triazoliumNHCprecursor generates highly enantioselective annulations fromsimple starting materials under mild reaction conditions[263 264] In an interesting example the catalysts facilitatehighly enantioselective cyclopentene forming annulations ofsimple enals and activated enones [265] Redox esterificationsand amidations of 120572-functionalized aldehydes using achiralcatalyst are also reported [266] Uniting unique activationmodes of N-heterocyclic carbene (NHC) catalysts with theconcept of domino reactions a new fast-growing field cameinto the spotlight in last couple of years or so [267ndash269]

Domino Michaelaldol reaction between 2-mercapto-quinoline-3-carbaldehydes and enals was catalyzed by di-phenylprolinol silyl ether producing 2H-thiopyrano[23-b]-quinolines in excellent yields and enantioselectivities [270]Zhao et al reported studies on ldquocooperative NHC andrutheniun redox catalysisrdquo in the oxidative esterificationof aldehydes [271] Blanc et al reported NHC mediatedorganocatalytic one-pot allylstannation to generate syn-diols[272] With enals as starting aldehydes elegant cascadeprocesses have been developed using oxidative carbene catal-ysis [273ndash276] Over the last few years there are examplesreported in literature where various organocatalysts rally

16 Journal of Catalysts

O

Oxone

OO

O

O

OO

R1 R1

R3

R3

R2 R2H2OCH3CN

Scheme 13

F3C

N+

F3C

Brminus

CF3

CF3

Figure 8 See [176]

N

O

N

N

F

F

F

F

F

+BF4minus

Figure 9

domino reactions and attract their application in organicprocesses in industries [174 175 180 181 183]

Apart from the aforementioned organocatalysts thereare other organic systems which upon appropriate acti-vation function as catalysts in useful asymmetric synthe-ses [155ndash157] 12-Dicarbonyl compounds because of theiradjacent multiple reactive centers upon activation act asefficient pronucleophiles in asymmetric organocatalyzed

N

O

NN+

Clminus

Figure 10

sequential or domino transformations including CndashC or CndashN bond formation [277] Cyclopropenone catalyzed con-version of aldoximes and primary amides into nitriles ina one-pot mild reaction widens the scope of the utiliza-tion of cyclopropenones in organic synthesis [278] Thefirst asymmetric organocatalytic synthesis by phosphinecatalyzed [3+2] cycloaddition of allenoates onto fullereneis reported to yield enantiomerically pure carbocyclicfullerene derivatives under mild conditions [279] A new[3+2] cycloadditioncycloreversion strategy for organocat-alytic and thermally allowed carbonyl-olefin metathesis isreported [280] Recently a strong evidence for halogenbond based organocatalysis is reported for the reactionof 1-chloroisochroman with ketene silyl acetals [281] Acidcatalyzed asymmetric acetalizations of aldehydes are alsodescribed [282] beta-Isocupreidine catalyzed the enantios-elective Morita-Baylis-Hillman reaction of maleimides withisatin derivatives to form 3-substituted 3-hydroxyoxindolederivatives [283 284]

Recent advances in asymmetric catalysis resulted in uti-lizing the less discussed electrophilic properties of iminiumtype intermediates in complex annulations of indoles [285286] and also pyridines [287 288] Shibatomi and Narayamadiscussed the catalytic enantioselective 120572-chlorination of car-bonyl compounds and stereospecific substitution reactions ofthe resulting optically active alkyl chlorides [289]

Though there is no relation between the developmentof two different fields of organocatalysis and gold catalysis

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

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[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

[17] J R Anderson and K C Pratt Introduction To Characterisationand Testing of Catalysts Academic Press Sydney Australia1985

[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

Journal of Catalysts 15

O NC OTMSN

OH

N

N

OH

N

OO

2 to 20mol catalyst

TMSCN CHCl3

OC2H5

OC2H5

OC2H5

OC2H5

H3CO

C6H5C6H5

OCH3

Scheme 11 Tian et al [233]

OO

O

OO

II

CH3CH3

CH3

H3C

H3C TIPSOTIPSO

H

H

H

PhPh

NB

minus

+

+

(CF3SO2)2N

20mol catalyst

16hoursDichloromethane minus78∘C

Scheme 12 See [250ndash256]

712 Shi Epoxidation Catalyst Tu et al reported a fructosederived ketone in efficient asymmetric epoxidation of trans-olefins (Scheme 13) [257] Epoxidation catalyst is able toepoxidize trans-alkenes and certain cis-alkenes with good toexcellent yields and selectivities [258 259] Marigo et alrsquosgroup reported an asymmetric organocatalytic epoxidationof 120572 120573-unsaturated aldehydes with environmentally friendlyoxidant hydrogen peroxide [260]

713 N-Heterocyclic Carbene (NHC) as Organocatalysts

7131 Rovis Catalyst The conjugate addition of an aldehydeto an 120572120573-unsaturated compound (Stetter reaction) is apractical methodology for the construction of 14-dicarbonylcompounds bearing quaternary stereocenters Triazoliumsalt in the presence of a base functions as an N-heterocycliccarbene organocatalyst (Figure 9) in highly enantioselectiveintramolecular Stetter reactions [261 262]

7132 Bode Catalyst Bodersquos studies on NHCs (Figure 10)mainly involve catalytic generation of reactive speciessuch as enolates homoenolates and activated carboxylates

N-Mesityl substituent on an imidazolium or triazoliumNHCprecursor generates highly enantioselective annulations fromsimple starting materials under mild reaction conditions[263 264] In an interesting example the catalysts facilitatehighly enantioselective cyclopentene forming annulations ofsimple enals and activated enones [265] Redox esterificationsand amidations of 120572-functionalized aldehydes using achiralcatalyst are also reported [266] Uniting unique activationmodes of N-heterocyclic carbene (NHC) catalysts with theconcept of domino reactions a new fast-growing field cameinto the spotlight in last couple of years or so [267ndash269]

Domino Michaelaldol reaction between 2-mercapto-quinoline-3-carbaldehydes and enals was catalyzed by di-phenylprolinol silyl ether producing 2H-thiopyrano[23-b]-quinolines in excellent yields and enantioselectivities [270]Zhao et al reported studies on ldquocooperative NHC andrutheniun redox catalysisrdquo in the oxidative esterificationof aldehydes [271] Blanc et al reported NHC mediatedorganocatalytic one-pot allylstannation to generate syn-diols[272] With enals as starting aldehydes elegant cascadeprocesses have been developed using oxidative carbene catal-ysis [273ndash276] Over the last few years there are examplesreported in literature where various organocatalysts rally

16 Journal of Catalysts

O

Oxone

OO

O

O

OO

R1 R1

R3

R3

R2 R2H2OCH3CN

Scheme 13

F3C

N+

F3C

Brminus

CF3

CF3

Figure 8 See [176]

N

O

N

N

F

F

F

F

F

+BF4minus

Figure 9

domino reactions and attract their application in organicprocesses in industries [174 175 180 181 183]

Apart from the aforementioned organocatalysts thereare other organic systems which upon appropriate acti-vation function as catalysts in useful asymmetric synthe-ses [155ndash157] 12-Dicarbonyl compounds because of theiradjacent multiple reactive centers upon activation act asefficient pronucleophiles in asymmetric organocatalyzed

N

O

NN+

Clminus

Figure 10

sequential or domino transformations including CndashC or CndashN bond formation [277] Cyclopropenone catalyzed con-version of aldoximes and primary amides into nitriles ina one-pot mild reaction widens the scope of the utiliza-tion of cyclopropenones in organic synthesis [278] Thefirst asymmetric organocatalytic synthesis by phosphinecatalyzed [3+2] cycloaddition of allenoates onto fullereneis reported to yield enantiomerically pure carbocyclicfullerene derivatives under mild conditions [279] A new[3+2] cycloadditioncycloreversion strategy for organocat-alytic and thermally allowed carbonyl-olefin metathesis isreported [280] Recently a strong evidence for halogenbond based organocatalysis is reported for the reactionof 1-chloroisochroman with ketene silyl acetals [281] Acidcatalyzed asymmetric acetalizations of aldehydes are alsodescribed [282] beta-Isocupreidine catalyzed the enantios-elective Morita-Baylis-Hillman reaction of maleimides withisatin derivatives to form 3-substituted 3-hydroxyoxindolederivatives [283 284]

Recent advances in asymmetric catalysis resulted in uti-lizing the less discussed electrophilic properties of iminiumtype intermediates in complex annulations of indoles [285286] and also pyridines [287 288] Shibatomi and Narayamadiscussed the catalytic enantioselective 120572-chlorination of car-bonyl compounds and stereospecific substitution reactions ofthe resulting optically active alkyl chlorides [289]

Though there is no relation between the developmentof two different fields of organocatalysis and gold catalysis

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

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[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

[17] J R Anderson and K C Pratt Introduction To Characterisationand Testing of Catalysts Academic Press Sydney Australia1985

[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

16 Journal of Catalysts

O

Oxone

OO

O

O

OO

R1 R1

R3

R3

R2 R2H2OCH3CN

Scheme 13

F3C

N+

F3C

Brminus

CF3

CF3

Figure 8 See [176]

N

O

N

N

F

F

F

F

F

+BF4minus

Figure 9

domino reactions and attract their application in organicprocesses in industries [174 175 180 181 183]

Apart from the aforementioned organocatalysts thereare other organic systems which upon appropriate acti-vation function as catalysts in useful asymmetric synthe-ses [155ndash157] 12-Dicarbonyl compounds because of theiradjacent multiple reactive centers upon activation act asefficient pronucleophiles in asymmetric organocatalyzed

N

O

NN+

Clminus

Figure 10

sequential or domino transformations including CndashC or CndashN bond formation [277] Cyclopropenone catalyzed con-version of aldoximes and primary amides into nitriles ina one-pot mild reaction widens the scope of the utiliza-tion of cyclopropenones in organic synthesis [278] Thefirst asymmetric organocatalytic synthesis by phosphinecatalyzed [3+2] cycloaddition of allenoates onto fullereneis reported to yield enantiomerically pure carbocyclicfullerene derivatives under mild conditions [279] A new[3+2] cycloadditioncycloreversion strategy for organocat-alytic and thermally allowed carbonyl-olefin metathesis isreported [280] Recently a strong evidence for halogenbond based organocatalysis is reported for the reactionof 1-chloroisochroman with ketene silyl acetals [281] Acidcatalyzed asymmetric acetalizations of aldehydes are alsodescribed [282] beta-Isocupreidine catalyzed the enantios-elective Morita-Baylis-Hillman reaction of maleimides withisatin derivatives to form 3-substituted 3-hydroxyoxindolederivatives [283 284]

Recent advances in asymmetric catalysis resulted in uti-lizing the less discussed electrophilic properties of iminiumtype intermediates in complex annulations of indoles [285286] and also pyridines [287 288] Shibatomi and Narayamadiscussed the catalytic enantioselective 120572-chlorination of car-bonyl compounds and stereospecific substitution reactions ofthe resulting optically active alkyl chlorides [289]

Though there is no relation between the developmentof two different fields of organocatalysis and gold catalysis

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

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[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

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[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

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[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

Journal of Catalysts 17

an interesting synthetic utility and merger of both catalyticsystems in the same reaction flask is explored [290]Following Are the Synthetic Methodologies Reported onMannich Reactions Using Various Organocatalytic SystemsAsymmetric three-component Mannich reaction and anti-Mannich reactions were reported by organocatalysts [122175] The title reaction provides facile access to enan-tioenriched 34-dihydroquinazolin-2(1H)-ones containing aquaternary stereogenic center in high yields with excellentenantioselectivities Subsequent transformations lead to theconvenient preparation of the anti-HIV drug DPC 083 andN-fused polycyclic compounds without loss of enantiomericexcess [291]

An asymmetric catalytic desulfonylative Mannich reac-tion of keto imines with aldehydes as catalyzed by diarylpro-linol silyl ether was developed It gave the Mannich productin good yieldwith excellent anti- and enantioselectivity [292]New chiral bis(betaine)s containing two catalytically activecenters have been designed and have proven to be promisingorganocatalysts for the directMannich type reaction of azlac-tones with a broad spectrum of aliphatic imines [293] Hongand Wang reviewed advances in asymmetric organocatalyticconstruction of 331015840-spirocyclic oxindoles [294] And theapplications of organocatalysts in total synthesis and natu-ral product synthesis include enantioselective synthesis ofAmaryllidaceaealkaloids (+)-vittatine (+)-epi-vittatine and(+)-buphanisine [295 296]

8 Heterogeneous Organocatalysis NewDirection in Research and Development

81 Making of Heterogenous Catalyst from HomogeneousCatalyst The Concept and Methodologies With the knowl-edge of heterogeneous catalysis and chemistry of materialsat hand several modified and different systems are madethese days and are tested for their catalytic applicationsin various organic transformations Following are the mostcommon and well-known methods for the heterogenizationof homogeneous catalysts

(i) impregnation(ii) occlusion in porous materials (ship-in-a-bottle)(iii) grafting or tethering (through covalent bond)Impregnation is the immobilisation of catalytic element

via electrostatic interactions with a solid support One ofthe famous examples includes Rh-diphosphine cationic com-plexes impregnated on anionic resins via ion-pair formation[297] Similarly organocatalysts supported on solid could beenvisioned to yield a recyclable catalyst

Heterogenisation via catalyst entrapment is a typicalmethod that is applied to zeolite supports and termed asldquoship-in-bottlerdquo catalysis A famous example includes in situsynthesis of the transition metal complex in support cages[298 299] The great practical advantages of ldquoship-in-bottlerdquosingle-site heterogeneous catalysts were well illustrated byZsigmond et alrsquos research [300] Similar approach retainingsteric factors could be applicable as anothermethodology forheterogenization of organocatalysts

Siliceous wall ofmesoporous SBA-16 material

Si

OOO

N C

H

Fe

Figure 11 See [177]

While in grafting the catalytic active site is directlyanchored on the support This procedure is previously usedfor supporting organometallic complexes (Figure 11) [177301ndash304] The tethering technique involves a spacer thatis introduced between the catalyst and the support Thecharacteristic chemical nature and the structure of the spacershould be chosen to avoid the steric hindrance if anyThoughstructurally different catalytic activity can be expected to besimilar to catalyst in homogeneous state

Catalyst immobilization has been widely explored withasymmetric transitionmetal catalysts and enzymes aiming toimprove their applicability and practicability Similarly theimmobilization strategy has also been frequently attemptedfor organocatalysis even before its renaissance The prepa-ration of supported or immobilized catalysts involve eitherorganic polymers such as linear non-cross-linked or cross-linked polymers as supports or porous inorganic solids suchas alumina silica zirconia clays zeolites MCM and SBAtype mesoporous materials Many inorganic supports haverobust composition and offer large surface areas due to thepresence of internal pores Different routes to immobilisationof (homogeneous) catalyst can alter the nature of the catalyticactive site When the anchoring of catalytic moieties onsilica is concerned the key aspect is the functionalization ofsilanol groups on the surface The pretreatment temperatureof the parent silica determines the nature of the hydroxygroups (isolated geminal or hydrogen bound) their loca-tion and reactivity In nanostructured mesoporous silica oftheMCM-41 type the reactivity of the siloxanes is consideredto be sufficient for covalent linking with a tether [305]Subsequent silylation with trimethylchlorosilane neutralizesresidual hydroxyl groups and increases the hydrophobicityVarious aluminosilicates and mesoporous silicas could beenvisioned as suitable hosts for encapsulating and anchoringorganocatalysts

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

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[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

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[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

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Carbohydrate Chemistry

International Journal of

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Journal of

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Advances in

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Analytical Methods in Chemistry

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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Theoretical ChemistryJournal of

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Analytical ChemistryInternational Journal of

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Quantum Chemistry

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Organic Chemistry International

ElectrochemistryInternational Journal of

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CatalystsJournal of

18 Journal of Catalysts

Organocatalysis has drawn a lot of interest in bothacademia and industry The fact is that the asymmetric ver-sion of organocatalysis is the fastest growing field of syntheticorganic chemistry Few applications in industries include(i) epoxidation of chalcones and (ii) alkylation of cyclicketones Along with a commentary on very recent researchendeavors in organocatalysis the scope of heterogeneousorganocatalysis in asymmetric synthesis other importantorganic reactions green chemistry and scope for industrialapplications are presented in this review

Organic functionalization of nanostructured nano-porous and other nanomaterials widens the range oftheir applications and allows for the manipulation of thesurface properties that control the interaction with variousorganic and inorganic guest species and thereby addsnew catalytic functions to the materials One of the basicpremises behind the preparation of these kinds of materials isaiming at the development of heterogeneous and supportedcatalysis for their practical purposes that would have distinctadvantages over widely investigated homogeneous catalystsand organometallic compounds that are vulnerable todecomposition due to oxidation of the ligand bound to themetal center

Using a rationale similar to that reported earlier for theimmobilisation of transition-metal amino acid complexes[306ndash310] amino acids with functional side chains that canreact with tethering silanes such as lysine arginine glutamicacid cysteine or amino acid derived organocatalysts couldbe covalently anchored to the inner walls of porous silicaand other relevant inorganic structuresThese materials havetherefore been identified as promising supports for makingorganocatalysts heterogeneous for industrial significant reac-tions This field is therefore well poised for their potentiallarge scale applications in industry

An organocatalyst attached to some sort ofsupportmaterial is called heterogenized organocatalystand this as the term implies makes the organocatalystheterogeneous and thereby brings in all the advantagesof heterogeneous catalysis to the system without losingthe intrinsic catalytic activity of the organocatalyst Whenused in heterogeneous system one ensures no leachingof catalyst entity into the reaction medium and simpleworkup or easy separation of catalyst from the productsSuch catalyst can be reused In order to obtain heterogeneousorganocatalyst many approaches have been exploredincluding impregnation to layered material [311] covalentgrafting to solid support [312 313] electrostatic interactionbetween organocatalyst and the support [314] encapsulationto porous material [309 310] and adsorptive method[315] Several solid supports have been introduced forheterogenizing of organocatalysts in terms of covalentgrafting such as polymer matrix zeolites amorphoussilica and mesoporous silica [316ndash319] Due to the strongcovalent bond with silica surface the covalently anchoredorganic moieties are supposed to be more resistant towardleaching during the catalytic reactions Typically theimmobilization of organocatalysts has been achieved viacovalent attachment onto solid supports such as polystyrene[319ndash323] poly(ethylene glycol) [324 325] and dendrimers

[326] However most of these supported organocatalystsdemonstrated reduced activity and selectivity comparingwith their small molecular parent catalysts There has alsobeen increasing examples of supported organocatalystsvia noncovalent strategies starting to show their potentialsin this field There are major progresses regarding thedevelopment of noncovalently supported asymmetricorganocatalysts with a focus on the immobilizationmethodstheir advantages applications and limitations Noncovalentimmobilization includes minimal modification of the parentcatalyst facile catalyst linkage and combinatorial flexibilityfor the identification of an optimal-supported catalystDifferent modes of immobilization such as acid-baseion-pair hydrophobic biphasic and self-assembled geltype give different types of heterogeneous organocatalystsThe catalysts obtained by different methods have theiradvantages and disadvantages at the same time There is ascope for developing new methodology for heterogenizationof organocatalysts

Immobilization is an effective methodology for heteroge-nizing an organic molecule onto inorganic material The twoprinciple mechanisms of organocatalysis are of both covalentand noncovalent nature which lead to (i) the formationof covalent adduct between catalyst and substrate and (ii)the processes that rely on noncovalent interactions suchas hydrogen bonding or within the catalytic cycle is theformation of ions pairs [327] Owing to the application oforganocatalysis in industrial setup strategies for heteroge-nizing organocatalysts are being explored in fine chemicalindustries as well as pharmaceutical industries Though thestability of an immobilised catalyst may vary in batch oper-ation and continuous flow operation at higher reaction tem-peratures such catalysts are expected to avail the advantagesof heterogeneous catalysis Heterogeneous organocatalysis iswell poised for its potential industrial applications in industrywith sustainable and energy efficient approaches In order toimplement the concepts of green chemistry and engineeringin the pharmaceutical industry one must develop large scaleorganocatalytic reactions processes that involve

(i) immobilization of organocatalysts (for recycling pur-poses)

(ii) no leaching problems due to covalent bonding withthe support unlike metal complexes

(iii) results superior to those obtainedwith free analogous(iv) solution phase catalysis

The immobilisation of amino acid derived organocatalystscould be covalently anchored to the inner walls of poroussilica and other relevant inorganic structuresThesematerialshave shown promise as heterogeneous organocatalysts forindustrial significant reactions such as the Hajos-Parrish-Eder-Sauer-Wiechert reaction [88] and intramolecular [4+2]cycloadditions [328] This approach has the potential toimprove recoverability and recyclability use far less mol ofcatalyst and potentially give rise to significant improvementsin activity and selectivity Organocatalysts can be cova-lently anchored to mesoporous silica by building on currentmethodologies that are reported in the literature Tethering

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

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[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

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[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

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[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

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Journal of

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Advances in

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Analytical Methods in Chemistry

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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

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The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

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Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

Journal of Catalysts 19

is carried out through the side chain or a functionalized sidechain of a derivatised amino acid because the mechanism ofcatalysis relies on the amino and carboxylate groups to be freefor substrate binding Through spatial constraints nature ofthe active site and a precise balance of substrate-catalyst-porewall interactions the stereoselectivity of the catalytic reactioncould also be suitably enhanced Judiciously controlling theorientation of the channels and the pore diameter of themesoporous support could facilitate enhancements in thedesired stereochemical outcome as observed earlier withanchored transition-metal amino acid complexes The rangeof substrates and scope of reactions that can be catalyzedby heterogenised amino acids and their derivatives are everexpanding and immobilisation of these organic moietiescould result in the design and development of more stablehighly active heterogeneous catalysts [329ndash331]The potentialfor expanding the scope and industrial applicability of het-erogenised organocatalysts demands a greater understandingof the synergistic effects between the support and theorganocatalyst say for example amino acid at a molecularlevel which could provide valuable insights on structure-property relationships and its mechanistic significance Thecurrent organocatalysts development is more focused onsolving practical asymmetric synthesis and processes [332]Following are some interesting examples reported in the field

Copolymer-supported heterogeneous organocatalyst isprepared and applied for asymmetric aldol addition inaqueous medium [333] Aldol reaction between acetoneand 4-nitrobenzaldehyde was catalyzed by covalently graftedlysine onto silica The immobilisation technique was foundto create well-defined and isolated catalytic sites offeringimproved activity and chemoselectivity when compared withthe homogeneous system [331]

Enantiomerically pure iminium cations supported onzeolite Y a microporous material and on Al-MCM-41 amesoporous material were found effective for the epox-idation of aryl alkenes by using peroxymonosulfate asthe stoichiometric oxidant The catalytic reaction gavehigh conversions and enantioselectivities The catalysts canbe simply recycled by filtration and their activity andselectivity are found much higher than the homogeneouscounterpart [334] Chiral organocatalyst team up withheterogeneous inorganic semiconductors form CndashC bondthrough stereoselective photocatalysis [330] Direct stere-oselective alpha-functionalization of aldehydes forming CndashC CndashN CndashF CndashBr and CndashS bonds is reported overorganocatalysts [335] Solvent-free noncovalent organocatal-ysis is reported on enantioselective addition of nitroalkanesto alkylideneindolenines [336] DMAP-NCP a new net-work nanoporous conjugated polymer containing 4-(NN-dimethylamino)pyridine catalytic moieties exhibits catalyticactivity in the acylation of alcohols and phenols even underneat and continuous flow conditions for practical applicationson a large scale [337] An asymmetric Diels-Alder reactionwas catalyzed with high efficiency and recyclability by asoluble ldquoself-supportedrdquo chiral organosilica polymer withembedded imidazolidinone catalytic moieties [338] Therole of some ionic liquids as organocatalysts or cocatalystsrequires further understanding and there is a scope for future

N

ON

O O

S

O

O

N S

O

O

Siliceous wall ofmesoporous SBA-16 material

+

OCH3

F3C CF3

Si

minus

Figure 12 Heterogenization of a basic ionic liquid bearing NTf2

minus

anion on mesoporous SBA-16 silica [178 179]

research in conceptualization of this field its applicationsand the context for heterogeneous organocatalysis (Figure 12)[178 179 339]

82 Heterogeneous Organocatalysts from Renewable Resour-ces Kuhbeck et al reported a critical assessment of theefficiency of neutral pH chitosan biohydrogel beads as recy-clable heterogeneous organocatalyst for a variety of CminusCbond formation reactions (ie aldol reaction Knoevenagelcondensation nitroaldol (Henry) reaction [340] ResearchersFrancoise Quignard (France) and Luca Bernardi (Italy)undertake development of new heterogeneous organocata-lysts based on polysaccharides (chitosan alginate or car-rageenan) The polysaccharides are made available fromrenewable resources and exploited for their intrinsic catalyticactivities For example chitosan is known to bring basicfunctionswhile alginate and carrageenan are acidic polymersThe variety of functional groups provides polysaccharideswith a surface reactivity especially appealing for specificcatalysis processes

Verma et al reported a cost effective environmen-tally benign easily accessible biodegradable recyclable andhighly efficient pyridinium based bifunctional organocata-lyst (ES-SO

3-C5H5NH+) grafted to the chemically modified

expanded starch a biomaterial for the synthesis of b-aminocarbonyls by aza-Michael reaction of amines to electrondeficient alkenes undermild reaction conditions (Scheme 14)[341]

Heterogenized or supported organocatalysts for exam-ple grafted polyHDMS offer engineering advantages and thefinal macromolecular properties strongly reflect the nature ofthe graftsOff late the use of polymethylhydrosiloxanePMHSanchored cinchona alkaloid derivatives has been reported[342]

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

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[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

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[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

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[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

20 Journal of Catalysts

NHX

N

X

SO

OO O_ N

HES1mol+

+

R1

R1

R2

R2

THF 2ml rt

Scheme 14

83 Heterogeneous Organocatalysts for Their Use underContinuous Flow Conditions In the spirit of developingecofriendly syntheses researchers are interested in immobi-lization of various organocatalysts known to be efficient inaqueous media and in their use under continuous flow [320]

An interesting tether-free but immobilized bifunctionalsquaramide organocatalyst [343] has found potential applica-tion in batch and flow reactions (Scheme 15) A polystyrene-supported highly recyclable squaramide organocatalyst forthe enantioselective Michael addition of 13 dicarbonyl com-pounds to 120573-nitrostyrenes has also found potential industri-ally utility [344]

Because of their stability and recyclability solid-supported organocatalysts (Scheme 16) are therefore partic-ularly suitable for continuous flow systems [154 345 346]which allow large scale synthesis usually accompanied byhigher turnover numbers The miniaturised flow reactorsallow improved control of mass and heat transfer and theinherently low reaction volume increases safety making themvaluable tools for green chemistry Reaction-progress kineticanalysis and nonlinear chromatography were applied toinvestigate a model aldol reaction performed in continuousflow microreactors packed with proline functionalizedsilica gel The study facilitated by an online instrumentalmonitoring assessed optimal operation and feed variables[154]

Enantiomerically pure iminium cations supported onmicroporous zeolite Y and on mesoporous Al-MCM-41 areeffective asymmetric catalysts for the epoxidation of a rangeof aryl alkenes giving high conversions quickly and withenantioselectivities (Schemes 17 and 18) [334]

Epoxides are versatile synthetic intermediate A lot hasbeen reported on ring opening methodologies of epox-ides over metal alkoxids amides metal halides metal tri-flates and so forth Organocatalysts are advantageous oversuch metal catalysts Schreiner published the NN1015840-bis[35-bis(trifluoromethyl) phenyl]thiourea catalyzed ring openingof epoxides with different nucleophiles such as aminesphenols and thiols in water with poor regioselectivity (1 1 to1 4) [347 348] Bifunctional primary amine-thioureas cat-alyze usually difficult Michael reactions [349 350] Bidentatehydrogen bond donors urea and thiourea are found to beuseful organocatalysts for the activation of carbonyl groupHine and coworkers reported meta- and para-substitutedphenols and biphenylenediols as double hydrogen bondingorganocatalysts for addition of diethylamine to phenyl gly-cidyl ether [351 352] And there are various examples ofcatalysts bearing multiple hydrogen bond donors [353 354]

9 Preindustrialization Organocatalysis

In 2004 a special issue of the Advanced Synthesis andCatalysis research journal was dedicated to organocatalysis[355] In year 2006 a special issue of the Advanced Synthesisand Catalysis research journal onMultiphase Catalysis GreenSolvents and Immobilization was published by professorCozzi describing in detail the immobilization of organiccatalysts [356] Several synthetic strategies are developed forthe polymeric immobilization of chiral organocatalysts [357ndash359] Lu and Toy reviewed organic polymer supports forsynthesis and for reagent and catalyst immobilization [360]A lot has been done on supported or immobilized enamineand iminium derivatives for their applications as heteroge-neous organocatalysts [361] A heterogeneous catalyst (L-Pro LDHs) was developed using intercalation of L-proline inMg-Al layered double hydroxides (LDH) An investigationof the thermal stability and optical stability showed that theimmobilization of the chiral catalytic centers in restrictedgalleries enhanced the enantiomeric stability against thermaltreatment and light irradiation Asymmetric aldol reactionof benzaldehyde and acetone was carried out using L-ProLDHs as catalyst resulting in a good yield (90) and a highenantiomeric excess (94) (Figure 13) Heterogenized L-proline catalyzed the asymmetric aldol reaction using anionicclays as intercalated support [182]

Calderon et al researched [362] the aldol reaction ofhydroxyacetone with different aldehydes using immobilizedproline on a mesoporous support assisted by heat andmicrowaves It was found that heterogenized L-proline onMCM-41 catalyzed aldol reactions in both hydrophilic andhydrophobic solvents and provided stereoselectivities insome cases complementary to the homogeneous catalystTheheterogeneous catalysts could be reused without significantloss of stereoselectivity In a recent example supramolec-ular assemblies of amphiphilic L-proline were regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reaction [363] Noncovalently supportedheterogeneous chiral amine is used as catalyst for asymmet-ric direct aldol and Michael addition reactions [364] Anamine grafted on amorphous silica performs as an effectiveorganocatalyst for microwave-promoted Michael reaction of13-dicarbonyl compounds in water [365] Silica immobi-lized N-hydroxyphthalimide was found to catalyze autoxi-dation [366] Silica identified as a useful support materialfor homogeneous catalysts facilitates the catalyst recoveryand reusability [367] A heterogeneous organocatalyst forcyanosilylation is also reported lately [368]

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

[1] ldquoOur Common Future Report of the World Commissionon Environment and Development United Nations (UN)Commission on Environment and Development (BrundtlandCommission) 1987rdquo Published as Annex to General Assem-bly document A42427 Development and International Co-operation Environment August 1987

[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

[17] J R Anderson and K C Pratt Introduction To Characterisationand Testing of Catalysts Academic Press Sydney Australia1985

[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

Journal of Catalysts 21

NN

O

R

Ph

Ph Ph Ph

N N

O

R

H

Br

N NH

N

O

O

H5mol CHCl3 20∘CNBS Na2CO3 20∘C O2N

NO2

+

R1

R1

CF3

CF3

Scheme 15

Ar

OO

O

Ar

O

Yield 95

O O

NH

PS N

O

HN

H

NO2

NO2

+

R1

R1R3

R3

R2

R2

9 1 to 99 1 dl

92ndash99 ee

Scheme 16

O

NR

N

O

[O]

+ +

lowastRlowast

R1

R1 R3

R3

R2 R2

Scheme 17 Mediation of alkene epoxidation by oxaziridinium cations [334]

R R

O O

OTPPP

2 equivalentDichloromethane

Scheme 18 Epoxidation of chromenes by MCM catalyst [334]

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

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[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

[17] J R Anderson and K C Pratt Introduction To Characterisationand Testing of Catalysts Academic Press Sydney Australia1985

[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

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Carbohydrate Chemistry

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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Medicinal ChemistryInternational Journal of

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Chromatography Research International

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Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

22 Journal of Catalysts

Hydrogen bonding space

Hydrogen bonding space

0210 nm

0135nm

0135nm

0210 nm

Figure 13 The schematic model of L-Pro LDHs (molar ratio of MgAl = 3 1 intercalated yield = 59 [182]

There are some interesting patents in the literature onusage of some organocatalysts in innovative chemical tech-nologies with some industrial application There is no needfor metal based catalysis thus making a contribution to greenchemistry In this context simple organic acids have beenused as catalyst for the modification of cellulose in wateron multi-ton scale [369] In recent years the emphasis hasbeen on the variety of nano(porous)materials for that hasfound use in such catalytic systems these include nanopar-ticles dendrimers metal oxides inorganic polymers andmesoporous materials such as MCM-n materials and SBA-n materials In 2009 a patent related to the use of magneticnanomaterial-supported glutathione and cysteine organocat-alysts as ldquogreenrdquo nanocatalysts for various reactions suchas Paal-Knorr reactions aza-Michael addition and pyrazolesynthesis was filed and later granted in year 2012 [370] Sul-fonamide based organocatalysts and method for their use arepatented by inventors RichGarrett Carter andHuaYang Pro-line sulfonamide organocatalysts performing various enan-tioselective or diastereoselective reactions such as the aldolreactions conjugate additions Michael additions RobinsonannulationsMannich reactions and alpha-aminooxylationsalpha-hydroxyaminations alpha-aminations and alkyla-tion reactions Among the various methodologies claimeda sulfonamide derived catalyst was used for the con-struction of all carbon bicycles such as [222]-bicycles[371]

Organocatalysts are blamed for not being recoverableafter a reaction There are interesting reports that studyhomogeneous or heterogeneous nanosupports for easy recov-ery of the organocatalysts Caminade et al identified per-fectly defined hyperbranched polyphosphorhydrazone den-drimers either neat or attached to siliceous solid material asnanosupports for easy recycling of organocatalysts [326 372ndash374]

10 Characterization Tools and Techniques

In order for us to research catalysis and relevant aspectswe may require spectroscopic techniques magnetic mea-surements transport and thermal measurements scattering

techniques microscopic techniques thin-film depositiontechniques and so forth The catalytic systems especiallythe heterogenized organocatalysts prepared can be char-acterized by X-ray diffraction (XRD) nitrogen sorptionscanning electron microscopy (SEM) transmission electronmicroscopy (TEM) FT-IR UV-Visible nuclearmagnetic res-onance (NMR) Raman and so forth In case of nanoporousmaterials the pore diameters could be uniformly tailoredThe NMR studies of organocatalysts in porous materialscould also be of importance for understanding the structureand bonding within the organic and inorganic part of acatalytic system There is always a scope for identifyingand utilizing new characterization techniques for study-ing catalytic systems and properties especially the surfacebehaviour hydrophilichydrophobicity interactions molec-ular sorption recognitions and so forth

11 Future Scope of HeterogeneousOrganocatalysts

It is always a risk to predict what the future holds forany research area but several aspects of modifications ofexisting catalysts and also heterogenisation of organocata-lysts onto some sort of robust high surface area supportincluding nanomaterials or nanoporous materials undoubt-edly attract researchersrsquo attention Tremendous efforts shouldbe directed towards the discovery and design of catalyticsystems with better efficiency new reactivity and greaterturnover numbers Perhaps the most crucial area of researchin the future will be the identification of important organictransformations at industries that are not available usingother branches of catalysis Given the huge growth andimpact of organocatalysis in its present form it will certainlybe exciting to observe the development of the field uponheterogenization

A variety of reactions such as reduction oxidationmulticomponent Mannich alkylation condensation depro-tection cycloaddition hydroxylation dehydration dehydro-genation transesterification reactions involving biomimeticoxygen-evolving catalysts and other important CndashC bond

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

[1] ldquoOur Common Future Report of the World Commissionon Environment and Development United Nations (UN)Commission on Environment and Development (BrundtlandCommission) 1987rdquo Published as Annex to General Assem-bly document A42427 Development and International Co-operation Environment August 1987

[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

[17] J R Anderson and K C Pratt Introduction To Characterisationand Testing of Catalysts Academic Press Sydney Australia1985

[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

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Carbohydrate Chemistry

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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

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Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Theoretical ChemistryJournal of

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Spectroscopy

Analytical ChemistryInternational Journal of

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Quantum Chemistry

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ElectrochemistryInternational Journal of

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CatalystsJournal of

Journal of Catalysts 23

forming reactions are well presented on the heterogenizedorganocatalysts under a variety of reaction conditions

For any large scale catalytic process the most salientconsiderations are cost and safety and so critic opinion onlow turnover numbers limiting the potential usage might notdiscourage the industrial applications Because organocata-lysts are often cheaper than metal based catalysts they can beused in larger quantities than metal based ones for the sameprice Moreover it is widely recognized in manufacturingthat the removal of toxic catalyst related impurities fromthe waste stream can often have a larger financial impactthan the turn over number of the catalyst In the comingyears various approaches for immobilisation will be con-sidered with a focus on whether a novel methodology forthe immobilisation of organocatalysts could be discoveredThe benefits of heterogenisation will become apparent onevaluation of the catalytic potential Apart from the natureof the support the degree of catalyst loading and selectionof reaction media or solvent tune the catalytic behaviourAlternatively immobilized organocatalysts can be preparedthat are linked to the solvents like ionic liquids that allowthe catalytic entity to be separate from the reaction mediumby simple extraction or filtration In another approach theimmobilized organocatalyst might permit us to perform thereactions in biphasic or different conditions This catalyticsystem and reaction conditions could find industrial appli-cation Scientific and technical tasks that researchers canundertake are the immobilization of the organocatalyst onsolvent and or onto the walls of a reactor Future catalystsdevelopment should be more oriented toward real problemsin synthetic processes It would be also interesting to see (i)the explorations of noncovalent interactions and entrapmentin nanosized materials in developing supported organocat-alysts (ii) fine tuning of the screened catalysts and theirthermal mechanical and catalytic stability (iii) evaluation ofcatalyst deactivation and its rejuvenation mechanisms

12 Conclusions

The literature survey and ideas jotted above do not fully claimto conceptualize all the aspects of this new field of heteroge-neous organocatalysis The aim of this review is to illustratethe significance of a variety of organic molecules as catalystsemployed for a wide variety of organic transformations Themost highlighted fact is that these organocatalysts representan interesting scope for heterogenization In the review ofliterature the basic concept of organocatalyst strategies forheterogenization preparation methods and various applica-tions of heterogeneous organocatalysts have been discussedLike in other heterogeneous catalytic systems the materialsor supports could also play very important role in the totalcatalyst system used as both catalyst and catalyst carriersTheemphasis has been on the variety of nano(porous)materialsthat have found or could find use in such catalytic systemsthese include nanoparticles dendrimers metal oxides inor-ganic polymers and mesoporous materials such as MCM-n materials and SBA-n materials (this is an Open Accessreview under the terms of the Creative CommonsAttributionLicense which permits readers to use and distribute this

e-review provided that the original research work is properlycited All rights are therefore reserved to the author andorrespective authors and researchers cited herein (2013))

In this review the author focused on applications oforganocatalysts in asymmetric synthesis synthesis of finechemicals and green chemistry The preceding pages arean account of recent research and developments made inthe use of organic molecules as catalysts It is highlightedthat organocatalysts are versatile which not only catalyze themost fundamental reactions in organic chemistry but alsofinds applications in processes of commercial importancein chemical industries Several very useful applications oforganocatalysts are in production of agrochemicals cleanenergy drugs polymers petrochemicals and so forth Inview of the globally increasing interest towards energy effi-cient and environmentally friendly chemical technology forindustries research on the development of robust recyclableselective metal-free easy-to-scale up catalysts and theiruseful preparation methods are thus the need of the hour

Great strides are still to be made in the synthesis andcharacterization of supported or immobilized organocat-alysts in order to apply them as heterogeneous catalyststhat emphasize applications in existing industrial processesThese catalysts are going to be modified in future and maketheir catalytic activities accessible in industrial setup forsustainable and environmentally benign technologies

The author has also outlined recent progress in theuse of heterogeneous organocatalysts by briefing the recentpublications in scientific publications Year 2012 saw thematicseries dedicated to showcase the current state of the art oforganocatalysis published by the Beilstein Journal of OrganicChemistry For those readers who are expecting an update onthe recent trends in organocatalysis the author lists herein[375ndash383] excellent reviews published in year 2013 on somevery specialized topics of organocatalysis

To summarize today the growing need for the atomefficiency energy efficiency and environmental concernsstemming from the increase in chemical products demandnecessitate the development of the ldquosustainable or envi-ronmentally benignrdquo production methods Asymmetric syn-thesis achieving atom economy is a challenge for organicsynthesis and homogeneous catalysis using metal complexesleads the way But the pharmaceutical entities and foodindustry products do not tolerate a contamination of eventraces of any such metals for that matter That why thereis a huge demand for metal-free organocatalysts leading to100 yield 100 ee of the desired product The need fromchemical industry especially pharmaceutical for reliableasymmetric transformations of molecular skeletons is higherthan ever Therefore (asymmetric) organocatalysis is attract-ing widespread attention and has become an important fieldof research And moreover heterogeneous organocatalysisis bringing in some important breakthroughs for industryespecially through flow chemistry

This review encloses 376 useful references for providingreaders with a well described state of the art The studiesto address the scope of this catalytic science are under-way The scientific discoveries and innovations involvingorganocatalysts are reported almost on a daily basis Many

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

[1] ldquoOur Common Future Report of the World Commissionon Environment and Development United Nations (UN)Commission on Environment and Development (BrundtlandCommission) 1987rdquo Published as Annex to General Assem-bly document A42427 Development and International Co-operation Environment August 1987

[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

[17] J R Anderson and K C Pratt Introduction To Characterisationand Testing of Catalysts Academic Press Sydney Australia1985

[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Carbohydrate Chemistry

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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Medicinal ChemistryInternational Journal of

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Chromatography Research International

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

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Analytical ChemistryInternational Journal of

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Quantum Chemistry

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Organic Chemistry International

ElectrochemistryInternational Journal of

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

24 Journal of Catalysts

researchers are joining this field especially to understand thecatalytic phenomena and develop heterogeneous catalysts forasymmetric synthetic methodologies for chemical industryLet us catalyze the green chemistry revolution As rightly saidby Professor Benjamin List ldquothe research in organocatalysisconstitutes the tip of the iceberg of a novel catalytic principle ofwhich the entire scope still remains to be fully uncoveredrdquo

Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Theauthor Isak R Shaikh thanksNational Chemical Labora-tory (httpwwwncl-indiaorg) Pune India for providingthe library facilities

References

[1] ldquoOur Common Future Report of the World Commissionon Environment and Development United Nations (UN)Commission on Environment and Development (BrundtlandCommission) 1987rdquo Published as Annex to General Assem-bly document A42427 Development and International Co-operation Environment August 1987

[2] M LancasterGreen Chemistry An Introductory TextThe RoyalSociety of Chemistry Cambridge UK 2002

[3] P T Anastas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1998

[4] J H Clark ldquoCatalysis for green chemistryrdquo Pure and AppliedChemistry vol 73 no 1 pp 103ndash111 2001

[5] J H Clark and C N Rhodes Clean Synthesis Using PorousInorganic Solid Catalysts RSC Clean Technology MonographsCambridge UK 2000

[6] W Ostwald ldquoDie Uberwindung des wissenschaftlichen Mate-rialismusrdquo in Verhandlungen der Gesellschaft Deutscher Natur-forscher und Arzte pp 155ndash168 1895

[7] R A Sheldon ldquoConsider the environmental quotientrdquo Chem-tech vol 25 pp 38ndash47 1994

[8] RA Sheldon andH vanBekkum EdsFineChemicalsThroughHeterogeneous Catalysis Wiley-VCH Weinheim Germany2001

[9] R A Sheldon and R S Downing ldquoHeterogeneous cat-alytic transformations for environmentally friendly produc-tionrdquo Applied Catalysis A vol 189 no 2 pp 163ndash183 1999

[10] R A Sheldon ldquoThe e factor fifteen years onrdquo Green Chemistryvol 9 no 12 pp 1273ndash1283 2007

[11] R A Sheldon ldquoE factors green chemistry and catalysis anodysseyrdquo Chemical Communications no 29 pp 3352ndash33652008

[12] R A Sheldon ldquoSelective catalytic synthesis of fine chemicalsopportunities and trendsrdquo Journal of Molecular Catalysis A vol107 no 1ndash3 pp 75ndash83 1996

[13] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryamp Industry vol 1 pp 12ndash15 1997

[14] R A Sheldon ldquoCatalysis the key to waste minimizationrdquoJournal of Chemical Technology and Biotechnology vol 68 pp381ndash388 1997

[15] G Ertl H Knozinger and J Weitkamp Eds Handbook ofHeterogeneous Catalysis Wiley-Vch Weinheim Germany 1997

[16] R A van Santen PW NM van Leeuwen J A Moulijn and BA Averill Eds Catalysis An Intergrated Approach ElsevierAmsterdam The Netherlands 2nd edition 1999

[17] J R Anderson and K C Pratt Introduction To Characterisationand Testing of Catalysts Academic Press Sydney Australia1985

[18] J M Walls and R Smith Eds Surface Science TechniquesPergamon 1994

[19] J W Niemantsverdriet Spectroscopy in Catalysis Wiley-VchWeinheim Germany 2007

[20] J J Bozell and G R Petersen ldquoTechnology development forthe production of biobased products from biorefinery carbo-hydratesmdashthe US Department of Energyrsquos ldquotop 10rdquo revisitedrdquoGreen Chemistry vol 12 no 4 pp 539ndash554 2010

[21] R A Gross M Ganesh andW Lu ldquoEnzyme-catalysis breathesnew life into polyester condensation polymerizationsrdquo Trendsin Biotechnology vol 28 no 8 pp 435ndash443 2010

[22] C J Li and T H Chan Organic Reactions in Aqueous MediaWiley-VCH New York NY USA 1997

[23] P A Grieco Organic Synthesis in Water Kluwer AcademicDordrecht The Netherlands 1997

[24] B M Trost ldquoAtom economymdasha challenge for organic synthesishomogeneous catalysis leads the wayrdquo Angewandte ChemieInternational Edition vol 34 no 3 pp 259ndash281 1995

[25] B Cornils and W A Herrmann in Applied HomogeneousCatalysis with Organometallic Compounds B Cornils and WA Herrmann Eds Wiley-VCH Weinheim Germany 2ndedition 2002

[26] B Cornils and W A Herrmann ldquoConcepts in homogeneouscatalysis the industrial viewrdquo Journal of Catalysis vol 216 no1-2 pp 23ndash31 2003

[27] S Bhaduri and D MukeshHomogeneous Catalysis JohnWileyamp Sons 2002

[28] G W Parshall and S D Ittel Homogeneous Catalysis JohnWiley amp Sons New York NY USA 1992 Emphasis on Indus-trial Applications

[29] B Cornils and W A Herrmann Eds Applied HomogeneousCatalysis by Organometallic Complexes Verlag Chemie Wein-heim Germany 1996

[30] I Ojima Ed Catalytic Asymmetric Synthesis Verlag VCHWeinheim Germany 1993

[31] R Noyori Asymmetric Catalysis in Organic Synthesis JohnWiley amp Sons New York NY USA 1994

[32] H-U Blaser A Indolese and A Schnyder ldquoApplied homoge-neous catalysis by organometallic complexesrdquo Current Sciencevol 78 no 11 pp 1336ndash1344 2000

[33] M Beller and H-U Blaser EdsOrganometallics as Catalysts inthe Fine Chemical Industry vol 42 of Topics in OrganometallicChemistry Springer 2012

[34] B R Cuenya ldquoSynthesis and catalytic properties of metalnanoparticles size shape support composition and oxidationstate effectsrdquo Thin Solid Films vol 518 no 12 pp 3127ndash31502010

[35] E Victor Henrich and P A Cox The Surface Science of MetalOxides Cambridge University Press Cambridge UK 1994

[36] HH Kung ldquoTransitionmetal oxidesrdquo in Surface Chemistry andCatalysis Elsevier Amsterdam The Netherlands 1989

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

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CatalystsJournal of

Journal of Catalysts 25

[37] K J Klabunde M Fazlul Hoq F Mousah and H MatsuhashildquoMetal Oxides and their physico-chemical properties in Catal-ysis and Synthesisrdquo in Preparative Chemistry Using SupportedReagents Academic Press London UK 1987

[38] H Schafer Chemiker-Zeitung vol 101 no 78 p 325 1977[39] H-C Zhou J R Long andOMYaghi ldquoIntroduction tometal-

organic frameworksrdquo Chemical Reviews vol 112 no 2 pp 673ndash674 2012

[40] D Farrusseng Ed Metal-Organic Frameworks ApplicationsFrom Catalysis to Gas Storage Wiley-VCH Weinheim Ger-many 2011

[41] N Rahmat A Z Abdullah and A R Mohamed ldquoA reviewmesoporous Santa Barbara amorphous-15 types synthesisand its applications towards biorefinery productionrdquo AmericanJournal of Applied Sciences vol 7 no 12 pp 1579ndash1586 2010

[42] S-H Wu C-Y Mou and H-P Lin ldquoSynthesis of mesoporoussilica nanoparticlesrdquo Chemical Society Reviews vol 42 pp3862ndash3875 2013

[43] A Bernardos and L Kourimska ldquoApplications of mesoporoussilicamaterials in food a reviewrdquoCzech Journal of Food Sciencesvol 31 no 2 pp 99ndash107 2013

[44] M N Timofeeva V N Panchenko Z Hasan and S-HJhung ldquoCatalytic potential of the wonderful chameleons nickelphosphate molecular sievesrdquo Applied Catalysis A vol 455 pp71ndash85 2013

[45] I R Shaikh and S-E Park ldquoMicrowave synthesis and catalyticapplications of novel cobalt incorporated nickel phosphaterdquoDiffusion and Defect Data PtB Solid State Phenomena vol 119pp 279ndash282 2007

[46] I R ShaikhNanoporous nickel phosphate and silicamaterials forheterogeneous oxidation catalysis [PhD thesis] Inha UniversityInchon Republic of Korea 2007 PhD thesis incompleteunpublished and in conflict between S-E Park and Isak RShaikh

[47] Y Tao H Kanoh L Abrams and K Kaneko ldquoMesopore-modified zeolites preparation characterization and applica-tionsrdquo Chemical Reviews vol 106 no 3 pp 896ndash910 2006

[48] M E Davis ldquoOrdered porous materials for emerging applica-tionsrdquo Nature vol 417 no 6891 pp 813ndash821 2002

[49] K Tsuji C W Jones and M E Davis ldquoOrganic-functionalizedmolecular sieves (OFMSs) I Synthesis and characterizationof OFMSs with polar functional groupsrdquo Microporous andMesoporous Materials vol 29 no 3 pp 339ndash349 1999

[50] C W Jones K Tsuji and M E Davis ldquoOrganic-functionalizedmolecular sieves as shape-selective catalystsrdquo Nature vol 393no 6680 pp 52ndash54 1998

[51] M E Davis ldquoThe quest for extra-large pore crystalline molec-ular sievesrdquo ChemistrymdashA European Journal vol 3 pp 1745ndash1750 1997

[52] B Notori ldquoMicroporous crystalline titanium silicatesrdquoAdvances in Catalysis vol 41 pp 253ndash334 1996

[53] R J Saxon ldquoCrystalline microporous titanium silicatesrdquo Topicsin Catalysis vol 9 no 1-2 pp 43ndash57 1999

[54] J M Thomas and R Raja ldquoDesign of a ldquogreenrdquo one-stepcatalytic production of 120576-caprolactam (precursor of nylon-6)rdquoProceedings of the National Academy of Sciences of the UnitedStates of America vol 102 no 39 pp 13732ndash13736 2005

[55] M Hartmann and L Kevan ldquoTransition-metal ions in alu-minophosphate and silicoaluminophosphate molecular sieveslocation interaction with adsorbates and catalytic propertiesrdquoChemical Reviews vol 99 no 3 pp 635ndash663 1999

[56] C S Cundy and P A Cox ldquoThe hydrothermal synthesis ofzeolites history and development from the earliest days to thepresent timerdquo Chemical Reviews vol 103 no 3 pp 663ndash7012003

[57] A Corma ldquoFrom microporous to mesoporous molecular sievematerials and their use in catalysisrdquo Chemical Reviews vol 97no 6 pp 2373ndash2419 1997

[58] G De M Gusso L Tapfer et al ldquoAnnealing behavior ofsilver copper and silver-copper nanoclusters in a silica matrixsynthesized by the sol-gel techniquerdquo Journal of Applied Physicsvol 80 no 12 pp 6734ndash6739 1996

[59] Y Wan and D Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[60] A K Cheetham G Ferey and T Loiseau Angewandte ChemieInternational Edition vol 38 p 3298 1999

[61] G Ferey ldquoMicroporous solids from organically templatedinorganic skeletons to hybrid frameworks ecumenism inchemistryrdquo Chemistry of Materials vol 13 pp 3084ndash3098 2001

[62] C N R Rao S Natarajan and R Vaidhyanathan ldquoMetalcarboxylates with open architecturesrdquo Angewandte ChemieInternational Edition vol 43 no 12 pp 1466ndash1496 2004

[63] F Schuth and W Schmidt ldquoMicroporous and mesoporousmaterialsrdquo Advanced Materials vol 14 pp 629ndash638 2002

[64] F Schuth K Sing and J Weitkamp Eds Handbook of PorousSolids vol I-V Wiley-VCH Weinheim Germany 2002

[65] Y Wan and D Y Zhao ldquoOn the controllable soft-templatingapproach to mesoporous silicatesrdquo Chemical Reviews vol 107no 7 pp 2821ndash2860 2007

[66] V Parvulescu C Anastasescu and B L Su ldquoBimetallic Ru-(CrNi or Cu) and La-(Co orMn) incorporatedMCM-41molecularsieves as catalysts for oxidation of aromatic hydrocarbonsrdquoJournal of Molecular Catalysis A vol 211 pp 143ndash148 2004

[67] S Vetrivel and A Pandurangan ldquoCo and Mn impregnatedMCM-41 their applications to vapour phase oxidation ofisopropylbenzenerdquo Journal ofMolecular Catalysis A vol 227 pp269ndash278 2005

[68] Y Wan D Zhang N Hao and D Zhao ldquoOrganic groupsfunctionalised mesoporous silicatesrdquo International Journal ofNanotechnology vol 4 p 66 2007

[69] V Ayala A Corma M Iglesias and F Sanchez ldquoMesoporousMCM41-heterogenised (salen)Mn and Cu complexes as effec-tive catalysts for oxidation of sulfides to sulfoxides isolationof a stable supported Mn(V)=O complex responsible of thecatalytic activityrdquo Journal of Molecular Catalysis A vol 221 pp201ndash208 2004

[70] Z G Hajos and D R Parrish ldquoAsymmetric synthesis of bicyclicintermediates of natural product chemistryrdquo The Journal ofOrganic Chemistry vol 39 no 12 pp 1615ndash1621 1974

[71] L Shu and Y Shi ldquoAn efficient ketone-catalyzed epoxidationusing hydrogen peroxide as oxidantrdquo The Journal of OrganicChemistry vol 65 pp 8807ndash8810 2000

[72] E J Corey F Xu and M C Noe ldquoA rational approach tocatalytic enantioselective enolate alkylation using a structurallyrigidified and defined chiral quaternary ammonium salt underphase transfer conditionsrdquo Journal of the American ChemicalSociety vol 119 pp 12414ndash12415 1997

[73] B Sellergren R N Karmalkar and K J Shea ldquoEnantioselectiveester hydrolysis catalyzed by imprinted polymers 2rdquo Journal ofOrganic Chemistry vol 65 no 13 pp 4009ndash4027 2000

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

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Spectroscopy

Analytical ChemistryInternational Journal of

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Quantum Chemistry

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Organic Chemistry International

ElectrochemistryInternational Journal of

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CatalystsJournal of

26 Journal of Catalysts

[74] J von Liebig ldquoUeber die Bildung des Oxamids aus CyanrdquoAnnalen der Chemie und Pharmacie vol 113 no 2 pp 246ndash2471860

[75] H D Dakin ldquoThe catalytic action of amino-acids peptonesand proteins in effecting certain synthesesrdquo Journal of BiologicalChemistry vol 7 p 49 1909

[76] W Langenbeck ldquoUber organische Katalysatoren III Die Bil-dung von Oxamid aus Dicyan bei Gegenwart von AldehydenrdquoJustus Liebigs Annalen der Chemie vol 469 p 16 1929

[77] W Langenbeck Die Organische Katalysatoren und ihreBeziehungen zu den Fermenten vol 2 Springer 1949

[78] W Langenbeck Fortschritte Der Chemischen Forschung vol 6Springer Berlin Germany 1966

[79] M M Vavon and P Peignier ldquoLrsquoapplication des alcaloıdes dansla synthese organiquerdquoBulletin de la Societe Chimique de Francevol 45 p 293 1929

[80] R Wegler ldquoUber die mit verschiedener Reaktionsgeschwin-digkeit erfolgende Veresterung der optischen Antipoden einesRacemates durch opt akt Katalysatorenrdquo Justus Liebigs Annalender Chemie vol 498 pp 62ndash73 1932

[81] S Pizzarello and A L Weber ldquoPrebiotic amino acids asasymmetric catalystsrdquo Science vol 303 no 5661 p 1151 2004

[82] G Bredig and P S Fiske Biochemische Zeitschrift vol 46 p 71912

[83] H Pracejus ldquoOrganische Katalysatoren LXI AsymmetrischeSynthesen mit Ketenen I Alkaloid-katalysierte asymmetrischeSynthesen von 120572-Phenyl-propionsaureesternrdquo Justus LiebigsAnnalen der Chemie vol 634 pp 9ndash22 1960

[84] H Pracejus ldquoAsymmetrische Synthesen mit Ketenen II Stere-ospezifische Addition von 120572-Phenyl-athylamin an Phenyl-methyl-ketenrdquo Justus Liebigs Annalen der Chemie vol 634 pp23ndash29 1960

[85] S-I Yamada and G Otani ldquoAsymmetric synthesis with aminoacid II asymmetric synthesis of optically active 44-disubsti-tuted-cyclohexenonerdquo Tetrahedron Letters vol 10 no 48 pp4237ndash4240 1969

[86] Z G Hajos and D R Parrish German Patent DE 2102623 1971[87] Z G Hajos andD R Parrish United States Patent US 3975442

1971[88] U Eder G Sauer and R Wiechert ldquoNew type of asymmetric

cyclization to optically active steroid CD partial structuresrdquoAngewandte Chemie International Edition vol 10 pp 496ndash4971971

[89] C Allemann R Gordillo F R Clemente P H-Y Cheong andKNHouk ldquoTheory of asymmetric organocatalysis of aldol andrelated reactions rationalizations and predictionsrdquo Accounts ofChemical Research vol 37 no 8 pp 568ndash569 2004

[90] H Wynberg ldquoAsymmetric catalysis by alkaloidsrdquo Topics inStereochemistry vol 16 pp 87ndash129 1986

[91] H Wynberg ldquoCatalytic asymmetric synthesis of chiral 4-substituted 2-oxetanonesrdquo The Journal of Organic Chemistryvol 50 pp 1977ndash1979 1985

[92] H Wynberg ldquoAsymmetric synthesis of (S)- and (R)-malic acidfrom ketene and chloralrdquo Journal of the American ChemicalSociety vol 104 pp 166ndash168 1982

[93] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 pp 2395ndash2396 2000

[94] T Bui and C F Barbas III ldquoA proline-catalyzed asymmetricRobinson annulation reactionrdquo Tetrahedron Letters vol 41 no36 pp 6951ndash6954 2000

[95] R B Woodward E Logusch K P Nambiar et al ldquoAsymmetrictotal synthesis of erythromcin 1 Synthesis of an erythronolideA secoacid derivative via asymmetric inductionrdquo Journal of theAmerican Chemical Society vol 103 no 11 pp 3210ndash3213 1981

[96] K A Ahrendt C J Borths and D W C MacMillan ldquoNewstrategies for organic catalysis the first highly enantioselectiveorganocatalytic dielsmdashAlder reactionrdquo Journal of the AmericanChemical Society vol 122 no 17 pp 4243ndash4244 2000

[97] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[98] N Vignola and B List ldquoCatalytic asymmetric intramolecular120572-alkylation of aldehydesrdquo Journal of the American ChemicalSociety vol 126 no 2 pp 450ndash451 2004

[99] A B Northrup and DW CMacMillan ldquoTwo-step synthesis ofcarbohydrates by selective aldol reactionsrdquo Science vol 305 no5691 pp 1752ndash1755 2004

[100] A B Northrup I K Mangion F Hettche and D W CMacMillan ldquoEnantioselective organocatalytic direct aldol reac-tions of 120572-oxyaldehydes step one in a two-step synthesis ofcarbohydratesrdquo Angewandte Chemie International Edition vol43 no 16 pp 2152ndash2154 2004

[101] L C Dias L J Steil and V D A Vasconcelos ldquoA short andefficient synthesis of (+)-prelactone BrdquoTetrahedron Asymmetryvol 15 no 1 pp 147ndash150 2004

[102] P M Pihko and A Erkkila ldquoEnantioselective synthesis ofprelactone B using a proline-catalyzed crossed-aldol reactionrdquoTetrahedron Letters vol 44 no 41 pp 7607ndash7609 2003

[103] A B Northrup and D W C MacMillan ldquoThe first direct andenantioselective cross-aldol reaction of aldehydesrdquo Journal ofthe American Chemical Society vol 124 no 24 pp 6798ndash67992002

[104] K Sakthivel W Notz T Bui and C F Barbas III ldquoAminoacid catalyzed direct asymmetric aldol reactions a bioorganicapproach to catalytic asymmetric carbon-carbon bond-formingreactionsrdquo Journal of theAmericanChemical Society vol 123 no22 pp 5260ndash5267 2001

[105] B List P Pojarliev and C Castello ldquoProline-catalyzed asym-metric aldol reactions between ketones and 120572-unsubstitutedaldehydesrdquo Organic Letters vol 3 no 4 pp 573ndash575 2001

[106] B List R A Lerner and C F Barbas III ldquoProline-catalyzeddirect asymmetric aldol reactionsrdquo Journal of the AmericanChemical Society vol 122 no 10 pp 2395ndash2396 2000

[107] B List R A Lerner and C F Barbas III ldquoEnantioselective aldolcyclodehydrations catalyzed by antibody 38C2rdquoOrganic Lettersvol 1 no 1 pp 59ndash61 1999

[108] J M Betancort and C F Barbas III ldquoDirect asymmetricorganocatalytic michael reactions of 120572120572-disubstituted aldehy-des with120573-nitrostyrenes for the synthesis of quaternary carbon-containing productsrdquo Organic Letters vol 6 pp 2527ndash25302004

[109] A Alexakis and O Andrey ldquoDiamine-catalyzed asymmetricMichael additions of aldehydes and ketones to nitrostyrenerdquoOrganic Letters vol 4 no 21 pp 3611ndash3614 2002

[110] B List P Pojarliev andH JMartin ldquoEfficient proline-catalyzedMichael additions of unmodified ketones to nitro olefinsrdquoOrganic Letters vol 3 no 16 pp 2423ndash2425 2001

[111] D Enders and A Seki ldquoProline-catalyzed enantioselectiveMichael additions of ketones to nitrostyrenerdquo Synlett no 1 pp26ndash28 2002

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

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Carbohydrate Chemistry

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Analytical Methods in Chemistry

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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Analytical ChemistryInternational Journal of

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Quantum Chemistry

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Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

Journal of Catalysts 27

[112] J M Betancort and C F Barbas III ldquoCatalytic direct asymmet-ric Michael reactions taming naked aldehyde donorsrdquo OrganicLetters vol 3 no 23 pp 3737ndash3740 2001

[113] J M Betancort K Sakthivel R Thayumanavan and C FBarbas III ldquoCatalytic enantioselective direct Michael additionsof ketones to alkylidenemalonatesrdquo Tetrahedron Letters vol 42no 27 pp 4441ndash4444 2001

[114] S Hanessian and V Pham ldquoCatalytic asymmetric conjugateaddition of nitroalkanes to cycloalkenonesrdquoOrganic Letters vol2 no 19 pp 2975ndash2978 2000

[115] M Yamaguchi Y Igarashi R S Reddy T Shiraishi and MHirama ldquoAsymmetric Michael addition of nitroalkanes toprochiral acceptors catalyzed by proline rubidium saltsrdquo Tetra-hedron vol 53 no 32 pp 11223ndash11236 1997

[116] N S Chowdari J T Suri and C F Barbas III ldquoAsymmetricsynthesis of quaternary 120572-and 120573-amino acids and 120573-lactams viaproline-catalyzed Mannich reactions with branched aldehydedonorsrdquo Organic Letters vol 6 no 15 pp 2507ndash2510 2004

[117] N S Chowdari D B Ramachary and C F Barbas IIIldquoOrganocatalysis in ionic liquids highly efficient L-proline-catalyzed direct asymmetric Mannich reactions involvingketone and aldehyde nucleophilesrdquo Synlett no 12 pp 1906ndash1909 2003

[118] B List P Pojarliev W T Biller and H J Martin ldquoTheproline-catalyzed direct asymmetric three-component Man-nich reaction scope optimization and application to the highlyenantioselective synthesis of 12-amino alcoholsrdquo Journal of theAmerican Chemical Society vol 124 no 5 pp 827ndash833 2002

[119] A Cordova W Notz G Zhong J M Betancort and C FBarbas III ldquoA highly enantioselective amino acid-catalyzedroute to functionalized 120572-amino acidsrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1842ndash1843 2002

[120] A Cordova S-IWatanabe F TanakaWNotz andC F BarbasIII ldquoA highly enantioselective route to either enantiomer ofboth 120572- and 120573-amino acid derivativesrdquo Journal of the AmericanChemical Society vol 124 no 9 pp 1866ndash1867 2002

[121] A Corodova andC F Barbas III ldquoanti-Selective SMP-catalyzeddirect asymmetric Mannich-type reactions synthesis of func-tionalized amino acid derivativesrdquo Tetrahedron Letters vol 43pp 7749ndash7752 2002

[122] B List ldquoThe direct catalytic asymmetric three-componentMannich reactionrdquo Journal of the American Chemical Societyvol 122 no 38 pp 9336ndash9337 2000

[123] F Shi W Tan R-Y Zhu G-J Xing and S-J Tu ldquocatalyticasymmetric five-component tandem reaction diastereo- andenantioselective synthesis of densely functionalized tetrahy-dropyridines with biological importancerdquo Advanced Synthesisamp Catalysis vol 355 no 8 pp 1605ndash1622 2013

[124] J W Yang M T Hechavarria Fonseca and B List ldquoCatalyticasymmetric reductiveMichael cyclizationrdquo Journal of the Amer-ican Chemical Society vol 127 no 43 pp 15036ndash15037 2005

[125] B List ldquoDirect catalytic asymmetric 120572-amination of aldehydesrdquoJournal of the American Chemical Society vol 124 pp 5656ndash5657 2002

[126] G Zhong ldquoA facile and rapid route to highly enantiopure12-diols by novel catalytic asymmetric 120572-aminoxylation ofaldehydesrdquo Angewandte Chemie International Edition vol 42no 35 pp 4247ndash4250 2003

[127] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[128] A Boslashgevig H Sunden and A Cordova ldquoDirect catalyticenantioselective alpha-aminoxylation of ketones a stereose-lective synthesis of alpha-hydroxy and alphaalpharsquo-dihydroxyketonesrdquo Angewandte Chemie International Edition vol 43 pp1109ndash1112 2004

[129] J Seayad and B List ldquoAsymmetric organocatalysisrdquo Organic ampBiomolecular Chemistry vol 3 pp 719ndash724 2005

[130] R R Shaikh A Mazzanti M Petrini G Bartoli and P Mel-chiorre ldquoProline-catalyzed asymmetric formal 120572-alkylation ofaldehydes via vinylogous iminium ion intermediates generatedfrom arylsulfonyl indolesrdquo Angewandte Chemie InternationalEdition vol 47 no 45 pp 8707ndash8710 2008

[131] R K Kunz and D W C MacMillan ldquoEnantioselectiveorganocatalytic cyclopropanations The identification of a newclass of iminium catalyst based upon directed electrostaticactivationrdquo Journal of the American Chemical Society vol 127no 10 pp 3240ndash3241 2005

[132] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaeligrsgaard and K A Joslashrgensen ldquoA general organocatalyst fordirect 120572-functionalization of aldehydes stereoselective CminusCCminusN CminusF CminusBr and CminusS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 p 18296 2005

[133] A Boslashgevig K Juhl N Kumaragurubaran W Zhuang and KA Joslashrgensen ldquoDirect organo-catalytic asymmetric120572-aminationof aldehydesmdasha simple approach to optically active 120572-aminoaldehydes 120572-amino alcohols and 120572-amino acidsrdquo AngewandteChemie International Edition vol 41 pp 1790ndash1793 2002

[134] M Marigo and K A Joslashrgensen ldquo120572-Heteroatom functional-izationrdquo in Enantioselective Organocatalysis P I Dalko EdChapter 22 Wiley-VCH Weinheim Germany 2007

[135] M Marigo T Schulte J Franzen and K A Joslashrgensen ldquoAsym-metric multicomponent domino reactions and highly enan-tioselective conjugated addition of thiols to 120572120573-unsaturatedaldehydesrdquo Journal of the American Chemical Society vol 127pp 15710ndash15711 2005

[136] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmerican Chemical Society vol 127 pp 6964ndash6965 2005

[137] A Carlone G Bartoli M Bosco L Sambri and P Mel-chiorre ldquoOrganocatalytic asymmetric hydrophosphination of120572120573-unsaturated aldehydesrdquo Angewandte Chemie InternationalEdition vol 46 no 24 pp 4504ndash4506 2007

[138] I Ibrahem R Rios J Vesely et al ldquoEnantioselective organ-ocatalytic hydrophosphination of 120572120573-unsaturated aldehydesrdquoAngewandte Chemie International Edition vol 46 no 24 pp4507ndash4510 2007

[139] X Yu and W Wang ldquoOrganocatalysis asymmetric cascadereactions catalysed by chiral secondary aminesrdquo Organic ampBiomolecular Chemistry vol 6 pp 2037ndash2046 2008

[140] D Enders M R M Huttl C Grondal and G Raabe ldquoControlof four stereocentres in a triple cascade organocatalytic reac-tionrdquo Nature vol 441 pp 861ndash863 2006

[141] A E Allen and D W C MacMillan ldquoEnantioselective 120572-arylation of aldehydes via the productive merger of iodoniumsalts and organocatalysisrdquo Journal of the American ChemicalSociety vol 133 no 12 pp 4260ndash4263 2011

[142] A E Allen and DW C MacMillan ldquoThe productive merger ofiodonium salts and organocatalysis a non-photolytic approachto the enantioselective 120572-trifluoromethylation of aldehydesrdquo

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

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Analytical Methods in Chemistry

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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

28 Journal of Catalysts

Journal of the American Chemical Society vol 132 no 14 pp4986ndash4987 2010

[143] H-W Shih M N Vander Wal R L Grange and D W CMacMillan ldquoEnantioselective 120572-benzylation of aldehydes viaphotoredox organocatalysisrdquo Journal of the American ChemicalSociety vol 132 no 39 pp 13600ndash13603 2010

[144] D W C MacMillan ldquoThe advent and development oforganocatalysisrdquo Nature vol 455 no 7211 pp 304ndash308 2008

[145] T D Beeson A Mastracchio J-B Hong K Ashton and D WC MacMillan ldquoEnantioselective organocatalysis using SOMOactivationrdquo Science vol 316 no 5824 pp 582ndash585 2007

[146] S G Ouellet A Walji and D W C MacMillan ldquoEnantiose-lective organocatalytic transfer hydrogenation reactions usingHantzsch estersrdquo Accounts of Chemical Research vol 40 pp1327ndash1339 2007

[147] Y Huang A M Walji C H Larsen and D W C MacMil-lan ldquoEnantioselective organo-cascade catalysisrdquo Journal of theAmerican Chemical Society vol 127 no 43 pp 15051ndash150532005

[148] S P Brown M P Brochu C J Sinz and D W C MacMillanldquoThe direct and enantioselective organocatalytic 120572-oxidation ofaldehydesrdquo Journal of the American Chemical Society vol 125no 36 pp 10808ndash10809 2003

[149] N A Para and D W C MacMillan ldquoNew strategies in organiccatalysis the first enantioselective organocatalytic Friedel-Crafts alkylationrdquo Journal of the American Chemical Society vol123 no 18 pp 4370ndash4371 2001

[150] W S Jen J J M Wiener and DW C MacMillan ldquoNew strate-gies for organic catalysis the first enantioselective organocat-alytic 13-dipolar cycloadditionrdquo Journal of the American Chem-ical Society vol 122 no 40 pp 9874ndash9875 2000

[151] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[152] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[153] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[154] O Bortolini A Cavazzini P P Giovannini et al ldquoA com-bined kinetic and thermodynamic approach for the interpre-tation of continuous-flow heterogeneous catalytic processesrdquoChemistrymdashA European Journal vol 19 no 24 pp 7802ndash78082013

[155] A Berkessel and H Groeger EdsAsymmetric OrganocatalysisFrom Biomimetic Concepts To Applications in Asymmetric Syn-thesisSpecial Issue Asymmetric Organocatalysis Wiley-VCHWeinheim Germany 2005

[156] A Berkessel and H Groeger Metal-Free Organic Catalysts inAsymmetric Synthesis Wiley-VCH Weinheim Germany 2004

[157] K N Houk and B List ldquoSpecial issue asymmetric organocatal-ysisrdquo Accounts of Chemical Research vol 37 no 8 p 487 2004

[158] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[159] H U Blaser and E Schmidt ldquoIntroductionrdquo in AsymmetricCatalysis on Industrial Scale H U Blaser and E Schmidt Edspp 1ndash19 Wiley-VCH Weinheim Germany 2004

[160] HU Blaser B Pugin and F Spindler ldquoProgress in enantioselec-tive catalysis assessed from an industrial point of viewrdquo Journalof Molecular Catalysis A vol 231 pp 1ndash20 2005

[161] H U Blaser ldquoEnantioselective catalysis in fine chemicalsproductionrdquo Chemical Communications pp 293ndash296 2003

[162] S S V Ramasastry H Zhang F Tanaka and C F Barbas IIIldquoDirect catalytic asymmetric synthesis of anti-12-amino alco-hols and syn-12-diols through organocatalytic anti-Mannichand syn-aldol reactionsrdquo Journal of the American ChemicalSociety vol 129 pp 288ndash289 2007

[163] Y Zhao J Rodrigo A H Hoveyda and M L SnapperldquoEnantioselective silyl protection of alcohols catalysed by anamino-acid-based small moleculerdquo Nature vol 443 no 7107pp 67ndash70 2006

[164] S Saha and J N Moorthy ldquoEnantioselective organocatalyticBiginelli reaction dependence of the catalyst on sterics hydro-gen bonding and reinforced chiralityrdquo The Journal of OrganicChemistry vol 76 pp 396ndash402 2011

[165] S Gore S Baskaran and B Koenig ldquoEfficient synthesis of34-dihydropyrimidin-2-ones in low melting tartaric acid-ureamixturesrdquo Green Chemistry vol 13 no 4 pp 1009ndash1013 2011

[166] N Li X H Chen J Song S W Luo W Fan and L ZGong ldquoHighly enantioselective organocatalytic Biginelli andBiginelli-like condensations reversal of the stereochemistry bytuning the 331015840-disubstituents of phosphoric acidsrdquo Journal ofthe American Chemical Society vol 132 p 10953 2010

[167] N Lu D Chen G Zhang andQ Liu ldquoTheoretical investigationon enantioselective Biginelli reaction catalyzed by naturaltartaric acidrdquo International Journal of Quantum Chemistry vol111 pp 2031ndash2038 2010

[168] M Lei ldquoAn efficient and environmentally friendly procedure forsynthesis of pyrimidinone derivatives by use of a Biginelli-typereactionrdquoMonatshefte fur Chemie vol 141 pp 1005ndash1008 2010

[169] Y Y Wu Z Chai X Y Liu G Zhao and S W WangldquoSynthesis of substituted 5-(Pyrrolidin-2-yl)tetrazoles and theirapplication in the asymmetric Biginelli reactionrdquo EuropeanJournal of Organic Chemistry vol 6 pp 904ndash911 2009

[170] M M Savant A M Pansuriya C V Bhuva N P Kapuriyaand Y T Naliapara ldquoEtidronic acid a new and efficient catalystfor the synthesis of novel 5-nitro-34-dihydropyrimidin-2(1H)-onesrdquo Catalysis Letters vol 132 no 1-2 pp 281ndash284 2009

[171] J N Sangshetti N D Kokare and D B Shinde ldquoOxalicacid as a versatile catalyst for one pot facile synthesis of34-dihydropyrimidin-2-(1H)-ones and their thione analoguesrdquoJournal of Heterocyclic Chemistry vol 45 no 4 pp 1191ndash11942008

[172] E Ramu V Kotra N Bansal R Varala and S R Adapa ldquoGreenapproach for the efficient synthesis of Biginelli compoundspromoted by citric acid under solvent-free conditionsrdquoRasayanJournal of Chemistry vol 1 pp 188ndash194 2008

[173] D B Ramachary N S Chowdari and C F Barbas III ldquoAmine-catalyzed direct self Diels-Alder reactions of 120572120573-unsaturatedketones in water synthesis of pro-chiral cyclohexanonesrdquoTetrahedron Letters vol 43 no 38 pp 6743ndash6746 2002

[174] D B Ramachary K Anebouselvy N S Chowdari and C FBarbas III ldquoDirect organocatalytic asymmetric heterodominoreactions the KnoevenagelDiels-Alderepimerization sequen-ce for the highly diastereoselective synthesis of symmetrical andnonsymmetrical synthons of benzoannelated centropolyquin-anesrdquo Journal of Organic Chemistry vol 69 no 18 pp 5838ndash5849 2004

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

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Analytical Methods in Chemistry

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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

Journal of Catalysts 29

[175] R Martın-Rapun X Fan S Sayalero M Bahramnejad FCuevas and M A Pericas ldquoHighly active organocatalysts forasymmetric anti-mannich reactionsrdquo ChemistrymdashA EuropeanJournal vol 17 no 32 pp 8780ndash8783 2011

[176] T Ooi M Taniguchi M Kameda and K Maruoka ldquoDirectasymmetric aldol reactions of glycine schiff base with aldehydescatalyzed by chiral quaternary ammonium saltsrdquo AngewandteChemie International Edition vol 41 pp 4542ndash4544 2002

[177] D R Burri I R Shaikh S-C Han and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-16rdquo Studies in Surface Science and Catalysis vol 165 pp 647ndash650 2007

[178] I R Shaikh ldquoHeterogenization of a basic ionic liquid bearingNTf2

- anion on mesoporous SBA-16 and its use as catalyst inknoevenagel reactionrdquo in Proceedings of the National Conferenceon Drug Designing and Discovery pp 81ndash85 DevchandCollege Arjun Nagar Ta Kagal District Kolhapur IndiaSeptember 2013 httpdevchandcollegeorge20proceed-ing203D13html

[179] I R Shaikh and A A Shaikh ldquoHeterogenization of ionic liquidcontainingHunig base onmesoporous SBA-16 and its use as cat-alyst in knovenagel condensationrdquo inProceedings of theNationalConference on Frontiers of Physical Chemical and BiologicalSciences (FPCBS rsquo13) University of Pune Ganeshkhind PuneIndia October 2013 published as special issue in EnvironmentObserver vol 13 pp 35-36 2013 httpwwwseeramorg

[180] D Petruzziello M Stenta A Mazzanti and P G CozzildquoA rational approach towards a new ferrocenyl pyrrolidinefor stereoselective enamine catalysisrdquo ChemistrymdashA EuropeanJournal vol 19 no 24 pp 7696ndash7700 2013

[181] S Sulzer-Mosse and A Alexakis ldquoChiral amines as organocata-lysts for asymmetric conjugate addition to nitroolefins and vinylsulfonesviaenamine activationrdquo Chemical Communications no30 pp 3123ndash3135 2007

[182] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 no 2 pp 319ndash327 2006

[183] L Albrecht G Dickmeiss C F Weise C Rodrıguez-Escrichand K A Joslashrgensen ldquoDienamine-mediated inverse-electron-demand hetero-diels-alder reaction by using an enantioselec-tive H-bond-directing strategyrdquo Angewandte Chemie Interna-tional Edition vol 51 no 52 pp 13109ndash13113 2012

[184] Q Ren and J Wang ldquoRecent developments in amine-catalyzednon-asymmetric transformationsrdquo Asian Journal of OrganicChemistry vol 2 no 7 pp 542ndash557 2013

[185] T Li J Zhu D Wu et al ldquoA strategy enabling enantioselectivedirect conjugate addition of inert aryl methane nucleophilesto enals with a chiral amine catalyst under mild conditionsrdquoChemistrymdashA European Journal vol 19 no 28 pp 9147ndash91502013

[186] G Talavera E Reyes J L Vicario and L Carrillo ldquoCooper-ative dienaminehydrogen-bonding catalysis enantioselectiveformal [2+2] cycloaddition of enals with nitroalkenesrdquo Ange-wandte Chemie International Edition vol 51 no 17 pp 4104ndash4107 2012

[187] D B Ramachary and Y V Reddy ldquoDienamine catalysis anemerging technology in organic synthesisrdquo European Journal ofOrganic Chemistry no 5 pp 868ndash887 2012

[188] J Chin F Mancin N Thavarajah D Lee A Lough and D SChung ldquoControlling diaza-Cope rearrangement reactions with

resonance-assisted hydrogen bondsrdquo Journal of the AmericanChemical Society vol 125 pp 15276ndash15277 2003

[189] H J KimH KimG Alhakimi et al ldquoPreorganization in highlyenantioselective diaza-Cope rearrangement reactionrdquo Journalof the American Chemical Society vol 127 pp 16370ndash163712005

[190] H J Kim W Kim A J Lough B M Kim and J ChinldquoA cobalt(III)-salen complex with an axial substituent in thediamine backbone stereoselective recognition of amino alco-holsrdquo Journal of the American Chemical Society vol 127 pp16776ndash16777 2005

[191] L Cui Y Zhu S Luo and J-P Cheng ldquoPrimary-tertiarydiaminebroslashnsted acid catalyzed CndashC coupling between para-vinylanilines and aldehydesrdquo ChemistrymdashA European Journal vol 19 no 29 pp 9481ndash9484 2013

[192] M Orlandi M Benaglia L Raimondi and G Celentano ldquo2-Aminoimidazolyl and 2-aminopyridyl (S)-prolinamides as ver-satile multifunctional organic catalysts for aldol Michael andDiels Alder reactionsrdquo European Journal of Organic Chemistryvol 12 pp 2346ndash2354 2013

[193] H Wang Y Wang H Song Z Zhou and C Tang ldquoBifunc-tional squaramide-catalyzed one-pot sequential Michael addi-tiondearomative bromination convenient access to opticallyactive brominated pyrazol-5(4H)-ones with adjacent quater-nary and tertiary stereocentersrdquo European Journal of OrganicChemistry vol 2013 no 22 pp 4844ndash4851 2013

[194] B Tan G Hernandez-Torres and C F Barbas III ldquoRationallydesigned amide donors for organocatalytic asymmetricMichaelreactionsrdquoAngewandte Chemie International Edition vol 51 no22 pp 5381ndash5385 2012

[195] D Nguyen R K Akhani C I Sheppard and S L WiskurldquoStructure-activity relationship of formamides as organocata-lysts the significance of formamide structure and conforma-tionrdquo European Journal of Organic Chemistry vol 12 pp 2279ndash2283 2013

[196] G Lelais andDWCMacMillan ldquoModern strategies in organiccatalysis the advent and development of iminium activationrdquoAldrichimica Acta vol 39 no 3 pp 79ndash87 2006

[197] S Lee and D W C MacMillan ldquoOrganocatalytic vinyl andFriedel-Crafts alkylations with trifluoroborate saltsrdquo Journal ofthe American Chemical Society vol 129 no 50 pp 15438ndash154392007

[198] N A Paras and D W C MacMillan ldquoNew strategiesin organocatalysisThe first enantioselective organocatalyticFriedel-Crafts alkylationrdquo Journal of the American ChemicalSociety vol 123 pp 4370ndash4371 2001

[199] M P Brochu S P Brown and DW C MacMillan ldquoDirect andenantioselective organocatalytic 120572-chlorination of aldehydesrdquoJournal of the American Chemical Society vol 126 no 13 pp4108ndash4109 2004

[200] T D Beeson and D W C MacMillan ldquoEnantioselective organ-ocatalytic 120572-fluorination of aldehydesrdquo Journal of the AmericanChemical Society vol 127 no 24 pp 8826ndash8828 2005

[201] M T H Fonseca and B List ldquoCatalytic asymmetric intramolec-ular Michael reaction of aldehydesrdquo Angewandte Chemie Inter-national Edition vol 43 no 30 pp 3958ndash3960 2004

[202] S G Ouellet J B Tuttle and D W MacMillan ldquoEnantioselec-tive organocatalytic hydride reductionrdquo Journal of the AmericanChemical Society vol 127 pp 32ndash33 2005

[203] MacMillan Imidazolidinone OrganoCatalysts are a trade-mark of Materia Inc httpswwwprincetoneduchemistrymacmillanpublicationsaldrichimicapdf

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

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CatalystsJournal of

30 Journal of Catalysts

[204] M C Holland S Paul W B Schweizer et al ldquoNoncovalentinteractions in organocatalysis modulating conformationaldiversity and reactivity in the MacMillan catalystrdquo AngewandteChemie International Edition vol 52 no 31 pp 7967ndash7971 2013

[205] G Chollet F Rodriguez and E Schulz ldquoA new method forrecycling asymmetric catalysts via formation of charge transfercomplexesrdquo Organic Letters vol 8 pp 539ndash542 2006

[206] L Xing J H Xie Y S Chen L X Wang and Q L Zhou ldquoSim-ply modified chiral diphosphine catalyst recycling via non-covalent absorption on carbon nanotubesrdquo Advanced Synthesisamp Catalysis vol 350 pp 1013ndash1016 2008

[207] R Akiyama and S Kobayashi ldquoMicroencapsulated and relatedcatalysts for organic chemistry and organic synthesisrdquoChemicalReviews vol 109 no 2 pp 594ndash642 2009

[208] C A Wang Y Zhang J Y Shi and W Wang ldquoA self-supported polymeric MacMillan catalyst for homogeneousorganocatalysis and heterogeneous recyclingrdquo ChemistrymdashAEuropean Journal vol 8 no 6 pp 1110ndash1114 2013

[209] J Seayad A M Seayad and B List ldquoCatalytic asymmetricPictet-Spengler reactionrdquo Journal of the American ChemicalSociety vol 128 no 4 pp 1086ndash1087 2006

[210] S Hoffmann A M Seayad and B List ldquoA powerful Broslashnstedacid catalyst for the organocatalytic asymmetric transfer hydro-genation of iminesrdquo Angewandte Chemie International Editionvol 44 no 45 pp 7424ndash7427 2005

[211] M Rueping E Sugiono C Azap TTheissmann and M BolteldquoEnantioselective Broslashnsted acid catalyzed transfer hydrogena-tion organocatalytic reduction of iminesrdquo Organic Letters vol7 no 17 pp 3781ndash3783 2005

[212] R I Storer D E Carrera Y Ni and D W C MacMillanldquoEnantioselective organocatalytic reductive aminationrdquo Journalof theAmericanChemical Society vol 128 no 1 pp 84ndash86 2006

[213] J Zhou and B List ldquoOrganocatalytic asymmetric reaction cas-cade to substituted cyclohexylaminesrdquo Journal of the AmericanChemical Society vol 129 no 24 pp 7498ndash7499 2007

[214] G B Rowland H Zhang E B Rowland S ChennamadhavuniY Wang and J C Antilla ldquoBroslashnsted acid-catalyzed imineamidationrdquo Journal of the American Chemical Society vol 127no 45 pp 15696ndash15697 2005

[215] T Akiyama Y Tamura J Itoh H Morita and K FuchibeldquoEnantioselective aza-Diels-Alder reaction catalyzed by a chiralBroslashnsted acid effect of the additive on the enantioselectivityrdquoSynlett no 1 Article ID Y07205ST pp 141ndash143 2006

[216] Y Su M J Bouma L Alcaraz et al ldquoOrganocatalytic enan-tioselective one-pot four-component ugi-type multicompo-nent reaction for the synthesis of epoxy-tetrahydropyrrolo[34-b]pyridin-5-onesrdquo ChemistrymdashA European Journal vol 18 no40 pp 12624ndash12627 2012

[217] D J Bayston J L Fraser M R Ashton A D Baxter ME C Polywka and E Moses ldquoPreparation and use of apolymer supported BINAP hydrogenation catalystrdquoThe Journalof Organic Chemistry vol 63 p 3137 1998

[218] D S Kundu J Schmidt C Bleschke A Thomas and SBlechert ldquoAmicroporous binol-derived phosphoric acidrdquoAnge-wandte Chemie International Edition vol 51 no 22 pp 5456ndash5459 2012

[219] Y Huang A K Unni A N Thadani and V H Rawal ldquoSingleenantiomers from a chiral-alcohol catalystrdquoNature vol 424 no6945 p 146 2003

[220] H M Guo L Cheng L F Cun L Z Gong A Q Mi and Y ZJiang ldquoL-Prolinamide-catalyzed direct nitroso aldol reactions

of 120572-branched aldehydes a distinct regioselectivity from thatwith L-prolinerdquo Chemical Communications no 4 pp 429ndash4312006

[221] N T McDougal and S E Schaus ldquoAsymmetric Morita-Baylis-Hillman reactions catalyzed by chiral Broslashnsted acidsrdquo Journalof the American Chemical Society vol 125 no 40 pp 12094ndash12095 2003

[222] P Vachal and E N Jacobsen ldquoStructure-based analysis andoptimization of a highly enantioselective catalyst for thestrecker reactionrdquo Journal of the AmericanChemical Society vol124 no 34 pp 10012ndash10014 2002

[223] G D Joly and E N Jacobsen ldquoThiourea-catalyzed enantios-elective hydrophosphonylation of imines practical access toenantiomerically enriched 120572-amino phosphonic acidsrdquo Journalof the American Chemical Society vol 126 p 4102 2004

[224] A G Wenzel and E N Jacobsen ldquoAsymmetric catalytic Man-nich reactions catalyzed by urea derivatives enantioselectivesynthesis of 120573-aryl-120573-amino acidsrdquo Journal of the AmericanChemical Society vol 124 pp 12964ndash12965 2002

[225] D E Fuerst and E N Jacobsen ldquoThiourea-catalyzed enantios-elective cyanosilylation of ketonesrdquo Journal of the AmericanChemical Society vol 127 no 25 pp 8964ndash8965 2005

[226] M S Taylor and E N Jacobsen ldquoHighly enantioselective cat-alytic acyl-Pictet-Spengler reactionsrdquo Journal of the AmericanChemical Society vol 126 no 34 pp 10558ndash10559 2004

[227] M S Talyor N Tokunaga and EN Jacobsen ldquoEnantioselectivethiourea-catalyzed acyl-mannich reactions of isoquinolinesrdquoAngewandte Chemie International Edition vol 44 pp 6700ndash6704 2005

[228] X Li C Yang J-L Jin X-S Xue and J-P Cheng ldquoSyn-thesis of optically enriched spirocyclic benzofuran-2-ones bybifunctional thiourea-base catalyzed double-Michael additionof benzofuran-2-ones to dienonesrdquo ChemistrymdashAn Asian Jour-nal vol 8 no 05 pp 997ndash1003 2013

[229] S-R Ban X-X Zhu Z-P Zhang H-Y Xie and Q-S LildquoBenzoylthioureandashpyrrolidine as another bifunctional organ-ocatalyst highly enantioselective michael addition of cyclohex-anone to nitroolefinsrdquo European Journal of Organic Chemistryvol 15 pp 2977ndash2980 2013

[230] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[231] M J OrsquoDonnell ldquoThe enantioselective synthesis of 120572-aminoacids by phase-transfer catalysis with achiral Schiff base estersrdquoAccounts of Chemical Research vol 37 pp 506ndash517 2004

[232] B Lygo and B J Andrews ldquoThe enantioselective synthesis of 120572-amino acids by phase-transfer catalysis with achiral Schiff baseestersrdquoAccounts of Chemical Research vol 37 pp 518ndash525 2004

[233] S-K Tian R Hong and L Deng ldquoCatalytic asymmetriccyanosilylation of ketones with chiral Lewis baserdquo Journal ofthe American Chemical Society vol 125 no 33 pp 9900ndash99012003

[234] T B Poulsen CAlemparte andKA Joslashrgensen ldquoEnantioselec-tive organocatalytic allylic aminationrdquo Journal of the AmericanChemical Society vol 127 pp 11614ndash11615 2005

[235] M Bella and K A Joslashrgensen ldquoOrganocatalytic enantioselectiveconjugate addition to alkynonesrdquo Journal of the AmericanChemical Society vol 126 pp 5672ndash5673 2004

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

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Analytical Methods in Chemistry

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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

Journal of Catalysts 31

[236] P Melchiorre ldquoCinchona-based primary amine catalysis inthe asymmetric functionalization of carbonyl compoundsrdquoAngewandte Chemie International Edition vol 51 no 39 pp9748ndash9770 2012

[237] E Arceo and P Melchiorre ldquoExtending the aminocatalyticHOMO-raising activation strategy where is the limitrdquo Ange-wandte Chemie International Edition vol 51 no 22 pp 5290ndash5292 2012

[238] C-K Pei and M Shi ldquoAsymmetric cyclization reactions ofallenoates with imines or 120572120573-unsaturated ketones catalyzed byorganocatalysts derived from cinchona alkaloidsrdquo ChemistrymdashA European Journal vol 18 no 22 pp 6712ndash6716 2012

[239] A Russo G Galdi G Croce and A Lattanzi ldquoHighly enantios-elective epoxidation catalyzed by cinchona thioureas synthesisof functionalized terminal epoxides bearing a quaternary stere-ogenic centerrdquo ChemistrymdashA European Journal vol 18 no 20pp 6152ndash6157 2012

[240] A Kumar and S S Chimni ldquoOrganocatalytic asymmetric directaldol reaction of pyruvic aldehyde dimethyl acetal with isatinderivativesrdquo European Journal of Organic Chemistry vol 2013no 22 pp 4780ndash4876 2013

[241] M-X Zhao H Zhou W-H Tang W-S Qu and M ShildquoCinchona alkaloid-derived thiourea-catalyzed diastereo- andenantioselective [3+2] cycloaddition reaction of isocyanoac-etates to isatins a facile access to optically active spirooxindoleoxazolinesrdquo Advanced Synthesis amp Catalysis vol 355 no 7 pp1277ndash1283 2013

[242] F Xu M Zacuto N Yoshikawa et al ldquoAsymmetric synthesisof telcagepant a CGRP receptor antagonist for the treatmentof migrainerdquo Journal of Organic Chemistry vol 75 no 22 pp7829ndash7841 2010

[243] G Rassu V Zambrano L Pinna et al ldquoDirect regio- diastereo- and enantioselective vinylogous Michael addition of prochiral3-alkylideneoxindoles to nitroolefinsrdquo Advanced Synthesis ampCatalysis vol 355 no 9 pp 1881ndash1886 2013

[244] S Brandau A Landa J Franzen M Marigo and K AJoslashrgensen ldquoOrganocatalytic conjugate addition of malonates toalphabeta-unsaturated aldehydes asymmetric formal synthesisof (-)-paroxetine chiral lactams and lactonesrdquo AngewandteChemie International Edition vol 45 no 26 pp 4305ndash43092006

[245] L J Hounjet C Bannwarth C N Garon C B Caputo SGrimme and D W Stephan ldquoCombinations of ethers andB(C6F5)3function as hydrogenation catalystsrdquo Angewandte

Chemie International Edition vol 52 no 29 pp 7492ndash74952013

[246] X-F Cai M-W Chen Z-S Ye et al ldquoAsymmetric transferhydrogenation of 3-nitroquinolines facile access to cyclic nitrocompounds with two contiguous stereocentersrdquo ChemistrymdashAn Asian Journal vol 8 no 7 pp 1381ndash1385 2013

[247] M Kitamura S Shirakawa and K Maruoka ldquoPowerful chiralphase-transfer catalysts for the asymmetric synthesis of alpha-alkyl- and alphaalpha-dialkyl-alpha-amino acidsrdquoAngewandteChemie International Edition vol 44 pp 1549ndash1551 2005

[248] T Ooi Y Arimura Y Hiraiwa et al ldquoHighly enantioselectivemonoalkylation of p-chlorobenzaldehyde imine of glycine tert-butyl ester under mild phase-transfer conditionsrdquo TetrahedronAsymmetry vol 17 pp 603ndash606 2006

[249] T Ooi and K Maruoka ldquoDevelopment and applications of C2-symmetric chiral phase-transfer catalystsrdquo Aldrichimica Actavol 40 no 3 pp 77ndash86 2007

[250] E J Corey R K Bakshi and S Shibata ldquoHighly enantioselectiveborane reduction of ketones catalyzed by chiral oxazaboro-lidines Mechanism and synthetic implicationsrdquo Journal of theAmerican Chemical Society vol 109 pp 5551ndash5553 1987

[251] E J Corey R K Bakshi S Shibata C P Chen and V K SinghldquoA stable and easily prepared catalyst for the enantioselectivereduction of ketones Applications to multistep synthesesrdquoJournal of the American Chemical Society vol 109 pp 7925ndash7926 1987

[252] EHMKirtonG Tughan R EMorris andRA Field ldquoRatio-nalising the effect of reducing agent on the oxazaborolidine-mediated asymmetric reduction of N-substituted iminesrdquoTetrahedron Letters vol 45 pp 853ndash855 2004

[253] B T Cho andY S Chun ldquoEnantioselective synthesis of opticallyactive metolachlor via asymmetric reductionrdquo TetrahedronAsymmetry vol 3 no 3 pp 337ndash340 1992

[254] B T Cho and Y S Chun ldquoAsymmetric reduction of N-substituted ketimines with the reagent prepared from boraneand (S)-(ndash)-2-amino-3-methyl-11-diphenylbutan-1-ol (itsunorsquosreagent) enantioselective synthesis of optically active sec-ondary aminesrdquo Journal of the Chemical Society Perkin Trans-actions vol 1 pp 3200ndash3201 1990

[255] R D Tillyer C Boudreau D Tschaen U-H Dolling and PJ Reider ldquoAsymmetric reduction of keto oxime ethers usingoxazaborolidine reagents The enantioselective synthesis ofcyclic amino alcoholsrdquo Tetrahedron Letters vol 36 no 25 pp4337ndash4340 1995

[256] D H Ryu and E J Corey ldquoTriflimide activation of a chiraloxazaborolidine leads to a more general catalytic system forenantioselective Diels-Alder additionrdquo Journal of the AmericanChemical Society vol 125 pp 6388ndash6390 2003

[257] Y Tu Z-X Wang and Y Shi ldquoAn efficient asymmetric epoxi-dation method for trans-olefins mediated by a fructose-derivedketonerdquo Journal of the American Chemical Society vol 118 no40 pp 9806ndash9807 1996

[258] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[259] Z-X Wang Y Tu M Frohn J-R Zhang and Y Shi ldquoAnefficient catalytic asymmetric epoxidation methodrdquo Journal ofthe American Chemical Society vol 119 no 46 pp 11224ndash112351997

[260] M Marigo J Franzen T B Poulsen W Zhuang and K AJoslashrgensen ldquoAsymmetric organocatalytic epoxidation of 120572120573-unsaturated aldehydes with hydrogen peroxiderdquo Journal of theAmericanChemical Society vol 127 no 19 pp 6964ndash6965 2005

[261] N Marion S Dıez-Gonzalez and S P Nolan ldquoInside covera molecular solomon link (Angew Chem Int Ed 1-22007)rdquoAngewandte Chemie International Edition vol 46 p 2 2007

[262] M S Kerr and T Rovis ldquoEnantioselective synthesis of quater-nary stereocenters via a catalytic asymmetric stetter reactionrdquoJournal of the American Chemical Society vol 126 no 29 pp8876ndash8877 2004

[263] M He J R Struble and J W Bode ldquoHighly enantiose-lective azadiene dielsminusalder reactions catalyzed by chiral N-heterocyclic carbenesrdquo Journal of the American Chemical Soci-ety vol 128 pp 8418ndash8420 2006

[264] M He G J Uc and J W Bode ldquoChiral N-heterocyclic carbenecatalyzed enantioselective oxodiene Diels-Alder reactions withlow catalyst loadingsrdquo Journal of the American Chemical Societyvol 128 pp 15088ndash15089 2006

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Advances in

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Analytical Methods in Chemistry

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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

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The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

32 Journal of Catalysts

[265] P-C Chiang J Kaeobamrung and J W Bode ldquoEnantiose-lective cyclopentene-forming annulations via NHC-catalyzedbenzoin-oxy-Cope reactionsrdquo Journal of the AmericanChemicalSociety vol 129 no 12 pp 3520ndash3521 2007

[266] S S Sohn and J W Bode ldquoN-heterocyclic carbene catalyzedCndashC bond cleavage in redox esterifications of chiral formylcy-clopropanesrdquoAngewandte Chemie International Edition vol 45pp 6021ndash6024 2006

[267] A Grossmann and D Enders ldquoN-heterocyclic carbene cat-alyzed domino reactionsrdquo Angewandte Chemie InternationalEdition vol 51 no 2 pp 314ndash325 2012

[268] D Enders R Hahn and I Atodiresei ldquoAsymmetric synthesis offunctionalized tetrahydronaphthalenes via an organocatalyticnitroalkane-michaelhenry domino reactionrdquo Advanced Syn-thesis amp Catalysis vol 355 no 6 pp 1126ndash1136 2013

[269] H Pellissier ldquoRecent developments in asymmetric organocat-alytic domino reactionsrdquo Advanced Synthesis amp Catalysis vol354 no 2-3 pp 237ndash294 2012

[270] LWu YWang H Song L Tang Z Zhou and C Tang ldquoEnan-tioselective organocatalytic domino Michaelaldol reactionsan efficient procedure for the stereocontrolled constructionof 2H-thiopyrano[23-b]quinoline scaffoldsrdquo ChemistrymdashAnAsian Journal vol 8 pp 2204ndash2210 2013

[271] J Zhao C Muck-Lichtenfeld and A Studer ldquoCooperative N-heterocyclic carbene (NHC) and ruthenium redox catalysisoxidative esterification of aldehydes with air as the terminaloxidantrdquo Advanced Synthesis amp Catalysis vol 355 no 6 pp1098ndash1106 2013

[272] R Blanc P Nava M Rajzman L Commeiras and J-L ParrainldquoN-Heterocyclic carbene mediated organocatalytic transfer oftin onto aldehydes an easy access to syn-diols and mechanisticstudiesrdquo Advanced Synthesis amp Catalysis vol 354 no 10 pp2038ndash2048 2012

[273] S De Sarkar A Biswas R C Samanta and A Studer ldquoCatal-ysis with N-heterocyclic carbenes under oxidative conditionsrdquoChemistrymdashA European Journal vol 19 no 15 pp 4664ndash46782013

[274] H U Vora P Wheeler and T Rovis ldquoExploiting acyl and enolazolium intermediates via N-hetero-cyclic carbene-catalyzedreactions of 120572-reducible aldehydesrdquo Advanced Synthesis ampCatalysis vol 354 no 9 pp 1617ndash1639 2012

[275] J Mo L Shen and Y R Chi ldquoDirect 120573-activation of saturatedaldehydes to formal Michael acceptors through oxidative NHCcatalysisrdquoAngewandte Chemie International Edition vol 52 no33 pp 8588ndash8591 2013

[276] M Hans J Wouters A Demonceau and L Delaude ldquoMech-anistic insight into the staudinger reaction catalyzed by N-heterocyclic carbenesrdquo ChemistrymdashA European Journal vol 19no 29 pp 9668ndash9676 2013

[277] W Raimondi D Bonne and J Rodriguez ldquo12-dicarbonylcompounds as pronucleophiles in organocatalytic asymmetrictransformationsrdquo Angewandte Chemie International Editionvol 51 no 1 pp 40ndash42 2012

[278] A Rai and L D S Yadav ldquoCyclopropenone-catalyzed directconversion of aldoximes and primary amides into nitrilesrdquoEuropean Journal of Organic Chemistry vol 10 pp 1889ndash18932013

[279] J Marco-Martınez V Marcos S Reboredo S Filippone andN Martın ldquoAsymmetric organocatalysis in fullerenes chem-istry enantioselective phosphine-catalyzed cycloaddition ofallenoates onto C

60rdquo Angewandte Chemie International Edition

vol 52 no 19 pp 5115ndash5119 2013

[280] A-L Lee ldquoOrganocatalyzed carbonylndasholefinmetathesisrdquoAnge-wandte Chemie International Edition vol 52 no 17 pp 4524ndash4525 2013

[281] F Kniep S H Jungbauer Q Zhang et al ldquoOrganocatalysisby neutral multidentate halogen-bond donorsrdquo AngewandteChemie International Edition vol 52 no 27 pp 7028ndash70322013

[282] J H Kim I Coric S Vellalath and B List ldquoThe catalyticasymmetric acetalizationrdquo Angewandte Chemie InternationalEdition vol 52 no 16 pp 4474ndash4477 2013

[283] P Chauhan and S S Chimni ldquoOrganocatalytic enantioselectiveMorita-Baylis-Hillman reaction of maleimides with isatinsrdquoAsian Journal of Organic Chemistry vol 2 no 7 pp 586ndash5922013

[284] P Chauhan J Kaur and S S Chimni ldquoAsymmetric organocat-alytic addition reactions of maleimides a promising approachtowards the synthesis of chiral succinimide derivativesrdquoChemistrymdashAn Asian Journal vol 8 no 2 pp 328ndash346 2013

[285] C C J Loh and D Enders ldquoExploiting the electrophilicproperties of indole intermediates new options in designingasymmetric reactionsrdquo Angewandte Chemie International Edi-tion vol 51 no 1 pp 46ndash48 2012

[286] A Martınez M J Webber S Muller and B List ldquoVersa-tile access to chiral indolines by catalytic asymmetric fischerindolizationrdquoAngewandte Chemie International Edition vol 52no 36 pp 948ndash9490 2013

[287] Z Shi and T-P Loh ldquoOrganocatalytic synthesis of highlyfunctionalized pyridines at room temperaturerdquo AngewandteChemie International Edition vol 52 no 33 pp 8584ndash85872013

[288] A VMalkov S StonciusM Bell et al ldquoMechanistic dichotomyin the asymmetric allylation of aldehydes with allyltrichlorosi-lanes catalyzed by chiral pyridine N-oxidesrdquo ChemistrymdashAEuropean Journal vol 19 no 28 pp 9167ndash9185 2013

[289] K Shibatomi and A Narayama ldquoCatalytic enantioselective 120572-chlorination of carbonyl compoundsrdquo Asian Journal of OrganicChemistry vol 2 no 10 pp 812ndash823 2013

[290] C C J Loh and D Enders ldquoMerging organocatalysis andgold catalysismdasha critical evaluation of the underlying conceptsrdquoChemistrymdashAEuropean Journal vol 18 no 33 pp 10212ndash102252012

[291] H-N Yuan S Wang J Nie W Meng Q Yao and J-AMa ldquoHydrogen-bond-directed enantioselective decarboxyla-tive Mannich reaction of 120573-ketoacids with ketimines applica-tion to the synthesis of anti-HIV drug DPC 083rdquo AngewandteChemie International Edition vol 52 no 14 pp 3869ndash38732013

[292] Y Hayashi D Sakamoto H Shomura and D HashizumeldquoAsymmetric Mannich reaction of 120572-keto imines catalyzed bydiarylprolinol silyl etherrdquo ChemistrymdashA European Journal vol19 no 24 pp 7678ndash7681 2013

[293] W-Q Zhang L-F Cheng J Yu and L-Z Gong ldquoA chiralbis(betaine) catalyst for the mannich reaction of azlactones andaliphatic iminesrdquo Angewandte Chemie International Editionvol 51 no 17 pp 4085ndash4088 2012

[294] L Hong and R Wang ldquoRecent advances in asymmetric organ-ocatalytic construction of 331015840-spirocyclic oxindolesrdquo AdvancedSynthesis amp Catalysis vol 355 no 6 pp 1023ndash1052 2013

[295] M-XWei C-TWang J-Y Du et al ldquoEnantioselective synthe-sis of Amaryllidaceae alkaloids (+)-vittatine (+)-epi-vittatineand (+)-buphanisinerdquo ChemistrymdashAn Asian Journal vol 8 no9 pp 1966ndash1971 2013

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

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Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

Journal of Catalysts 33

[296] H-J Yang F-J Xiong X-F Chen and F-E Chen ldquoHighlyenantioselective thiolysis of prochiral cyclic anhydrides cat-alyzed by amino alcohol bifunctional organocatalysts and itsapplication to the synthesis of pregabalinrdquo European Journal ofOrganic Chemistry vol 2013 no 21 pp 4495ndash4489 2013

[297] R Selke and M Capka ldquoCarbohydrate phosphinites as chiralligands for asymmetric syntheses catalyzed by complexespart VIII immobilization of cationic rhodium(I) chelates ofphenyl 46-O-(R)-benzylidene-23-bis(O-diphenylphosphino)-120573-D-glucopyranoside on silicardquo Journal of Molecular Catalysisvol 63 pp 319ndash334 1990

[298] M Ichikawa ldquolsquoShip-in-Bottlersquo catalyst technology Novel tem-plating fabrication of platinum group metals nanoparticles andwires inmicromesoporesrdquo PlatinumMetals Review vol 44 no1 pp 3ndash14 2000

[299] V Trevisan M Signoretto S Colonna V Pironti and GStrukul ldquoMicroencapsulated chloroperoxidase as a recyclablecatalyst for the enantioselective oxidation of sulfides withhydrogen peroxiderdquo Angewandte Chemie International Editionvol 43 no 31 pp 4097ndash4099 2004

[300] A Zsigmond F Notheisz G Csjernyik and J-E BackvallldquoRuthenium-catalyzed aerobic oxidation of alcohols on zeolite-encapsulated cobalt salophen catalystrdquo Topics in Catalysis vol19 no 1 pp 119ndash124 2002

[301] N Legagneux E Jeanneau AThomas et al ldquoGrafting reactionof platinum organometallic complexes on silica-supported orunsupported heteropolyacidsrdquo Organometallics vol 30 no 7pp 1783ndash1793 2011

[302] Y Wan F Zhang Y Lu and H Li ldquoImmobilization of Ru(II)complex on functionalized SBA-15 and its catalytic perfor-mance in aqueous homoallylic alcohol isomerizationrdquo Journalof Molecular Catalysis A vol 267 pp 165ndash172 2007

[303] D R Burri I R Shaikh K-M Choi and S-E Park ldquoFacileheterogenization of homogeneous ferrocene catalyst on SBA-15and its hydroxylation activityrdquo Catalysis Communications vol8 no 4 pp 731ndash735 2007

[304] M Kuroki T AsefaWWhitnal et al ldquoSynthesis and propertiesof 135-benzene periodic mesoporous organosilica (PMO)novel aromatic PMO with three point attachments and uniquethermal transformationsrdquo Journal of the American ChemicalSociety vol 124 no 46 pp 13886ndash13895 2002

[305] T Maschmeyer F Rey G Sankar and J M Thomas ldquoHetero-geneous catalysts obtained by grafting metallocene complexesonto mesoporous silicardquo Nature vol 378 pp 159ndash162 1995

[306] L Hamidipour Z Ghasemzadeh F Farzaneh and M GhandildquoImmobilization of Cu(II)-histidine complex onAl-MCM-41 ascatalyst for epoxidation of alkenesrdquo Journal of Sciences vol 23no 1 pp 29ndash36 2012

[307] J G Mesu D Baute H J Tromp E E Van Faassen andB M Weckhuysen ldquoSynthesis and characterization of zeoliteencaged enzyme-mimetic copper histidine complexesrdquo Studiesin Surface Science and Catalysis vol 143 pp 287ndash293 2002

[308] B M Weckhuysen A A Verberckmoes L Fu and RA Schoonheydt ldquoZeolite-encapsulated copper(II) amino acidcomplexes synthesis spectroscopy and catalysisrdquo Journal ofPhysical Chemistry vol 100 no 22 pp 9456ndash9461 1996

[309] D Xuereb J Dzierzak and R Raja ldquoBiomimetic single-site het-erogeneous catalysts design strategies and catalytic potentialrdquoin Heterogenized Homogeneous Catalysts For Fine ChemicalsProduction vol 33 of Catalysis by Metal Complexes pp 37ndash632010

[310] P Barbaro and F Liguori Eds Heterogenized HomogeneousCatalysts for Fine Chemicals Production vol 33 ofMaterials andProcesses Series Catalysis by Metal Complexes Springer 2010

[311] Z An W Zhang H Shi and J He ldquoAn effective heterogeneousl-proline catalyst for the asymmetric aldol reaction usinganionic clays as intercalated supportrdquo Journal of Catalysis vol241 pp 319ndash327 2006

[312] J W Wiench Y S Avadhut N Maity et al ldquoCharacterizationof covalent linkages in organically functionalized MCM-41mesoporous materials by solid-state NMR and theoreticalcalculationsrdquo Journal of Physical Chemistry B vol 111 no 15 pp3877ndash3885 2007

[313] Q Gao W Xu Y Xu et al ldquoAmino acid adsorption onmesoporous materials influence of types of amino acids modi-fication of mesoporous materials and solution conditionsrdquoTheJournal of Physical Chemistry B vol 112 no 7 pp 2261ndash22672008

[314] S Luo J Li L Zhang H Xu and J P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[315] C Aprile F Giacalone M Gruttadauria et al ldquoNew ionicliquid-modified silica gels as recyclable materials for l-proline-orH-Pro-Pro-Asp-NH2-catalyzed aldol reactionrdquoGreenChem-istry vol 9 no 12 pp 1328ndash1334 2007

[316] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[317] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[318] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[319] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis Catalysis vol 348 pp 1391ndash1412 2006

[320] C Ayats A H Henseler and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[321] D Font C Jimeno and M A Pericas ldquoPolystyrene-supportedhydroxyproline an insoluble recyclable organocatalyst for theasymmetric aldol reaction in waterrdquo Organic Letters vol 8 pp4653ndash4655 2006

[322] D Font S Sayalero C Jimeno and M A Pericas ldquoToward anartificial aldolaserdquo Organic Letters vol 10 pp 337ndash340 2008

[323] D Font S Sayalero A Bastero C Jimeno and M A PericasldquoToward an artificial aldolaserdquo Organic Letters vol 12 p 26782010

[324] M Benaglia M Cinquini F Cozzi A Puglisi and GCelentano ldquoPoly(ethylene-glycol)-supported proline a recy-clable aminocatalyst for the enantioselective synthesis of 120574-nitroketones by conjugate additionrdquo Journal of Molecular Catal-ysis A vol 204-205 pp 157ndash163 2003

[325] D Q Xu S P Luo Y F Wang et al ldquoOrganocatalysts wrappedaround by poly(ethylene glycol)s (PEGs) a unique host-guestsystem for asymmetric Michael addition reactionsrdquo ChemicalCommunications no 42 pp 4393ndash4395 2007

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

34 Journal of Catalysts

[326] A M Caminade A Ouali M Keller and J P MajoralldquoOrganocatalysis with dendrimersrdquo Chemical Society Reviewsvol 41 pp 4113ndash4125 2012

[327] L Zhang S Luo and J-P Cheng ldquoNon-covalent immobi-lization of asymmetric organocatalystsrdquo Catalysis Science andTechnology vol 1 no 4 pp 507ndash516 2011

[328] B-C Hong H-C Tseng and S-H Chen ldquoSynthesis of aro-matic aldehydes by organocatalytic [4+2] and [3+3] cycloaddi-tion of 120572120573-unsaturated aldehydesrdquo Tetrahedron vol 63 no 13pp 2840ndash2850 2007

[329] M J Gaunt C C C Johansson A McNally and N T VoldquoEnantioselective organocatalysisrdquo Drug Discovery Today vol12 no 1-2 pp 8ndash27 2007

[330] D J Xuereb and R Raja ldquoDesign strategies for engineeringselectivity in bio-inspired heterogeneous catalystsrdquo CatalysisScience and Technology vol 1 no 4 pp 517ndash534 2011

[331] D J Xuereb Strategies for organocatalyst heterogenisation andperformance in selective transformations [PhD thesis] Univer-sity of Southampton 2012

[332] D E De Vos I F J Vankelecom and P A Jacobs Eds ChiralCatalyst Immobilization and Recycling Wiley-VCH WeinheimGermany 2000

[333] J Zhou J Wan X Ma and W Wang ldquoCopolymer-supportedheterogeneous organocatalyst for asymmetric aldol addition inaqueous mediumrdquo Organic amp Biomolecular Chemistry vol 10pp 4179ndash4185 2012

[334] P C Bulman Page A Mace D Arquier et al ldquoTowards het-erogeneous organocatalysis chiral iminium cations supportedon porous materials for enantioselective alkene epoxidationrdquoCatalysis Science amp Technology vol 3 pp 2330ndash2339 2013

[335] J Franzen M Marigo D Fielenbach T C Wabnitz AKjaersgaard and K A Joslashrgensen ldquoA general organocatalystfor direct120572-functionalization of aldehydes stereoselective CndashCCndashN CndashF CndashBr and CndashS bond-forming reactions Scope andmechanistic insightsrdquo Journal of the American Chemical Societyvol 127 no 51 pp 18296ndash18304 2005

[336] M Fochi L Gramigna A Mazzanti et al ldquoSolvent-free non-covalent organocatalysis enantioselective addition of nitroalka-nes to alkylideneindolenines as a flexible gateway to opticallyactive tryptamine derivativesrdquo Advanced Synthesis amp Catalysisvol 354 pp 71373ndash71380 2012

[337] Y Zhang Y Zhang Y L Sun et al ldquo4-(NN-dimethylam-ino)pyridine-embedded nanoporous conjugated polymer asa highly active heterogeneous organocatalystrdquo ChemistrymdashAEuropean Journal vol 18 no 20 pp 6328ndash6334 2012

[338] C A Wang Y Zhang J Y Shi andWWang ldquoA self-supportedpolymeric MacMillan catalyst for homogeneous organocataly-sis and heterogeneous recyclingrdquoChemistrymdashAnAsian Journalvol 8 no 6 pp 1110ndash1114 2013

[339] V Lucchini M Noe M Selva M Fabris and A Perosa ldquoCoop-erative nucleophilic-electrophilic organocatalysis by ionic liq-uidsrdquo Chemical Communications vol 48 no 42 pp 5178ndash51802012

[340] D Kuhbeck G Saidulu K R Reddy and D D Dıaz ldquoCriticalassessment of the efficiency of chitosan biohydrogel beads asrecyclable and heterogeneous organocatalyst for CndashC bondformationrdquo Green Chemistry vol 14 pp 378ndash392 2012

[341] S Verma S L Jain and B Sain ldquoAn efficient biomaterialsupported bifunctional organocatalyst (ESndashSO

3

- C5H5NH+) for

the synthesis of 120573-amino carbonylsrdquo Organic amp BiomolecularChemistry vol 9 pp 2314ndash2318 2011

[342] M S DeClue and J S Siegel ldquoPolysiloxane-bound ligandaccelerated catalysis a modular approach to heterogeneous andhomogeneous macromolecular asymmetric dihydroxylationligandsrdquo Organic amp Biomolecular Chemistry vol 2 pp 2287ndash2298 2004

[343] G Kardos and T Soos ldquoTether-free immobilized bifunctionalsquaramide organocatalysts for batch and flow reactionsrdquoEuropean Journal of Organic Chemistry vol 2013 no 21 pp4490ndash4494 2013

[344] P Kasaplar P Riente C Hartmann and M A PericasldquoA polystyrene-supported highly recyclable squaramideorganocatalyst for the enantioselective Michael addition of13-dicarbonyl compounds to 120573-nitrostyrenesrdquo AdvancedSynthesis amp Catalysis vol 354 no 16 pp 2905ndash2910 2013

[345] K E Alza C Rodrıguez-Escrich S Sayalero A Bastero andM A Pericas ldquoA solid-supported organocatalyst for highlystereoselective batch and continuous-flowmannich reactionsrdquoChemistrymdashA European Journal vol 15 no 39 pp 10167ndash101722009

[346] P Riente J Yadav and M A Pericas ldquoA solid-supportedorganocatalyst for continuous-flow enantioselective aldol reac-tionsrdquo ChemSusChem vol 5 no 2 pp 320ndash325 2012

[347] M Kotke and P Schreiner ldquo(Thio)Urea Organocatalystsrdquo inHydrogen Bonding in Organic Synthesis P M Pihko Ed pp141ndash352 Wiley-VCH 2009

[348] Y Takemoto ldquoDevelopment of chiral thiourea catalysts and itsapplication to asymmetric catalytic reactionsrdquo Chemical andPharmaceutical Bulletin vol 58 pp 593ndash601 2010

[349] M Tsakos C G Kokotos and G Kokotos ldquoPrimary amine-thioureas with improved catalytic properties for ldquodifficultrdquoMichael reactions efficient organocatalytic syntheses of (S)-baclofen (R)-baclofen and (S)-phenibutrdquo Advanced Synthesisand Catalysis vol 354 no 4 pp 740ndash746 2012

[350] M Tsakos and C G Kokotos ldquoOrganocatalytic ldquoDifficultrdquoMichael reaction of ketones with nitrodienes utilizing a primaryaminemdashthiourea based on di-tert-butyl aspartaterdquo EuropeanJournal of Organic Chemistry vol 2012 no 3 pp 576ndash580 2012

[351] J Hine S-M Linden and V M Kanagasabapathy ldquo18-Biphenylenediol is a double-hydrogen-bonding catalyst forreaction of an epoxide with a nucleophilerdquo Journal of theAmerican Chemical Society vol 107 no 4 pp 1082ndash1083 1985

[352] J Hine S M Linden and V M Kanagasabapathy ldquoDouble-hydrogen-bonding catalysis of the reaction of phenyl glycidylether with diethylamine by 18-biphenylenediolrdquoThe Journal ofOrganic Chemistry vol 50 pp 5096ndash5099 1985

[353] C K De E G Klauber and D Seidel ldquoMerging nucleophilicand hydrogen bonding catalysis an anion binding approachto the kinetic resolution of aminesrdquo Journal of the AmericanChemical Society vol 131 pp 17060ndash17061 2009

[354] R P Herrera V Sgarzani L Bernardi and A Ricci ldquoCat-alytic enantioselective friedel-crafts alkylation of indoles withnitroalkenes by using a simple thiourea organocatalystrdquo Ange-wandte Chemie International Edition vol 44 pp 6576ndash65792005

[355] ldquoSpecial issue on ldquoOrganocatalysisrdquordquo Advanced Synthesis ampCatalysis vol 346 no 9-10 2004

[356] F Cozzi ldquoImmobilization of organic catalysts when why andhowrdquo Advanced Synthesis amp Catalysis vol 348 pp 1367ndash13902006

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

Journal of Catalysts 35

[357] T E Kristensen and T Hansen ldquoPolymer-supported chiralorganocatalysts synthetic strategies for the road towards afford-able polymeric immobilizationrdquo European Journal of OrganicChemistry no 17 pp 3179ndash3204 2010

[358] M Benaglia F Cozzi and A Puglisi ldquoPolymer-supportedorganic catalystsrdquo Chemical Reviews vol 103 no 9 pp 3401ndash3429 2003

[359] M Benaglia Ed Recoverable and Recyclable Catalysts JohnWiley amp Sons Chichester UK 2009

[360] J Lu and P H Toy ldquoOrganic polymer supports for synthesis andfor reagent and catalyst immobilizationrdquoChemical Reviews vol109 no 2 pp 815ndash838 2009

[361] M Gruttadauria F Giacalone and R Noto ldquoSupported prolineand proline-derivatives as recyclable organocatalystsrdquoChemicalSociety Reviews vol 37 no 8 pp 1666ndash1688 2008

[362] F Calderon R Fernandez F Sanchez and A Fernandez-Mayoralas ldquoAsymmetric aldol reaction using immobilized pro-line on mesoporous supportrdquo Advanced Synthesis amp Catalysisvol 347 no 10 pp 1395ndash1403 2005

[363] L Qin L Zhang Q Jin J Zhang B Han and M LiuldquoSupramolecular assemblies of amphiphilic L-proline regulatedby compressed CO

2as a recyclable organocatalyst for the

asymmetric aldol reactionrdquo Angewandte Chemie InternationalEdition vol 52 no 30 pp 7761ndash7765

[364] S Luo J Li L Zhang H Xu and J-P Cheng ldquoNoncovalentlysupported heterogeneous chiral amine catalysts for asymmetricdirect aldol and Michael addition reactionsrdquo ChemistrymdashAEuropean Journal vol 14 no 4 pp 1273ndash1281 2008

[365] H Hagiwara S Inotsume M Fukushima T Hoshi and TSuzuki ldquoHeterogeneous amine catalyst grafted on amorphoussilica an effective organocatalyst for microwave-promotedMichael reaction of 13-dicarbonyl compounds in waterrdquoChem-istry Letters vol 35 no 8 pp 926ndash927 2006

[366] I Hermans J Van Deun K Houthoofd J Peeters and P AJacobs ldquoSilica-immobilizedN-hydroxyphthalimide an efficientheterogeneous autoxidation catalystrdquo Journal of Catalysis vol251 no 1 pp 204ndash212 2007

[367] A Corma and H Garcia ldquoSilica-bound homogenous catalystsas recoverable and reusable catalysts in organic synthesisrdquoAdvanced Synthesis amp Catalysis vol 348 pp 1391ndash1412 2006

[368] K Yamaguchi T Imago Y Ogasawara J Kasai M Kotani andNMizuno ldquoAn immobilized organocatalyst for cyanosilylationand epoxidationrdquoAdvanced Synthesis andCatalysis vol 348 no12-13 pp 1516ndash1520 2006

[369] A Cordova and J Hafren ldquoDirect Homogeneous and Hetero-geneousOrganicAcid andAminoAcid-CatalyzedModificationof Amines and Alcoholsrdquo International Patent WO 2006068611A1 20060629

[370] R S Verma and V Polshettiwar ldquoMagnetic nanoparticle-supported glutathione as a sustainable organocatalystrdquo Patentno US 8324125 B2 December 2012

[371] R CGarrett andHYang ldquoSulfonamide-BasedOrganocatalysisandMethod for their Userdquo Patent no US 8 399 684 B2 March2013

[372] A M Caminade C O Turrin R Laurent A Ouali and BDelavaux-Nicot Eds Dendrimers Towards Catalytic Materialand Biomedical Uses John Wiley amp Sons Chichester UK 2011

[373] P Servin R Laurent L Gonsalvi et al ldquoGrafting of water-soluble phosphines to dendrimers and their use in catalysispositive dendritic effects in aqueous mediardquo Dalton Transac-tions no 23 pp 4432ndash4434 2009

[374] M Keller A Perrier R Linhardt et al ldquoDendrimers ornanoparticles as supports for the design of efficient and recover-able organocatalystsrdquo Advanced Synthesis amp Catalysis vol 355no 9 pp 1748ndash1754 2013

[375] Thematic Series ldquoOrganocatalysisrdquo (Guest Editor BenjaminList) Beilstein Journal of Organic Chemistry 2012 httpwwwbeilstein-journalsorgbjocbrowsesingleSerieshtmsn=27

[376] Y S Lee M M Alam and R S Keri ldquoEnantioselectivereactions of N-acyliminium ions using chiral organocatalystsrdquoChemistrymdashAnAsian Journal vol 8 no 12 pp 2906ndash2919 2013

[377] F Lv S Liu and W Hu ldquoRecent advances in the use of chiralbroslashnsted acids as cooperative catalysts in cascade and multi-component reactionsrdquo Asian Journal of Organic Chemistry vol2 no 10 pp 824ndash836 2013

[378] W Yan X Shi and C Zhong ldquoSecondary amines as lewis basesin nitroalkene activationrdquo Asian Journal of Organic Chemistryvol 2 no 11 pp 904ndash914 2013

[379] S Ulf and M Rainer ldquoRecent advances in organocatalyticmethods for asymmetric CndashC bond formationrdquo ChemistrymdashAEuropean Journal vol 19 no 43 pp 14346ndash14396 2013

[380] S Narayanaperumal D G Rivera R C Silva and M WPaixao ldquoTerpene-derived bifunctional thioureas in asymmetricorganocatalysisrdquo ChemCatChem vol 5 no 10 pp 2756ndash27732013

[381] L-W Xu ldquoPowerful amino acid derived bifunctional phosphinecatalysts bearing a hydrogen bond donor in asymmetric synthe-sisrdquo ChemCatChem vol 5 no 10 pp 2775ndash2784 2013

[382] N Kielland C J Whiteoak and A W Kleij ldquoStereoselectivesynthesis with carbon dioxiderdquo Advanced Synthesis amp Catalysisvol 355 no 11-12 pp 2115ndash2138 2013

[383] S Mohammadi R Heiran R P Herrera and E Marques-Lopez ldquoIsatin as a strategic motif for asymmetric catalysisrdquoChemCatChem vol 5 no 8 pp 2131ndash2148 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of