Tetrahedron Letters Vol. 54, Issue 33, 2013

Contents

COMMUNICATIONS

Optical Pd2+ sensing by rhodamine hydrazone ligands: different stoichiometries in aqueous/nonaqueous environments pp 4357–4361

Honglin Li, Jianfang Cao, Hao Zhu, Jiangli Fan*, Xiaojun Peng*

The triazolyl analogue of the trityl cation pp 4362–4364

Mohamed Oukessou, Yves Génisson*, Dounia El Arfaoui, Abdeslem Ben-Tama, El Mestafa El Hadrami, Remi Chauvin*

(CF3CO)2O

CH2Cl2, 0°C

CNN

N

N NN

Ph

Ph

N NN

Ph Nu-E

Nu

CNN

NNNN

Ph

NNN Ph

Ph

« trizyl cation » 10 examples

OH

CNN

NNNN

Ph

NNN Ph

Ph - EE = H, K, ZnEtNu = O-, N-, S-or C-nucleophile

tris(1,2,3-triazolyl)methanol

Nardokanshone A, a new type of sesquieterpenoid–chalcone hybrid from Nardostachys chinensis pp 4365–4368

Peng-Cheng Wang, Xin-Hui Ran, Huai-Rong Luo, Yi-Min Zheng, Yu-Qing Liu, Jiang-Miao Hu*, Jun Zhou*

O

OOH

H3CO

OO

OCH3

4347

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Tetrahedron Letters

journal homepage: www.elsevier .com/ locate/ tet le t

Chemoselective oxidative hydrolysis of EWG protected a-arylamino vinyl bromides to a-arylamino-a0-bromoacetones pp 4369–4372

Vittorio Pace*, Laura Castoldi, María J. Hernáiz, Andrés R. Alcántara, Wolfgang Holzer

NBrPG

NOPG

BrCa(BrO)2 (2.0 equiv.)

PG = Ac, Moc, Boc, Ts, 4-NsR = H, Me, NO2, CN, F

R RMeCN-AcOH (5:2 v/v)

H2O, 0 °C, 1h

Environmentally benign process for the synthesis of 2,3-disubstituted benzo[b]thiophenes using electrophiliccyclization

pp 4373–4376

Seoyoung Kim, Nikesh Dahal, Tanay Kesharwani*

SMeCuSO4/NaX

EtOH, r.t.R

SR

XX = I, Br, ClR = aryl, vinly, alkyl, TMS,

Organic synthesis in deep eutectic solvents: Paal–Knorr reactions pp 4377–4379

Scott Handy*, Kevin Lavender

OR R'

OR"NR R'

CC/U80 C, 12h

H2NR"

R, R' = Me or Ph

Remarkable difference in fluorescence lifetimes of the crystalline states of dibenzoylmethanatoboron difluorideand its diisopropyl derivative

pp 4380–4384

Mirai Tanaka, Eisuke Ohta, Atsushi Sakai, Yuichi Yoshimoto, Kazuhiko Mizuno, Hiroshi Ikeda*

4348 Contents / Tetrahedron Letters 54 (2013) 4347–4355

Relative configuration of luminaolide pp 4385–4387

Norihito Maru*, Toshiyasu Inuzuka, Keita Yamamoto, Makoto Kitamura, Peter J. Schupp, Kaoru Yamada, Daisuke Uemura*

Synthesis and spectroscopic properties of 5-tert-butyl-3-(trifluoromethyl)phthalonitrile: a novel precursor for thesynthesis of phthalocyanines

pp 4388–4391

Łukasz Łapok*, Arkadiusz Gut, Maria Nowakowska

Diastereoselective construction of continuous all-carbon quaternary centers via intramolecular oxidativecoupling reaction

pp 4392–4396

Weiqing Xie*, Hexiang Wang, Feng Fan, Junshan Tian, Zhiwei Zuo, Weiwei Zi, Kun Gao*, Dawei Ma*

BnNNBn

OO

O

O

trans-2

BnN

O

NBn

O

OO

4

BnN

O

NBn

O

OO

cis-1NaHMDS, I2, THF

-78oC to rtLDA, I2, THF/HMPA

-78oC

An unexpected involvement of ethyl-2-cyano-2-(hydroxyimino) acetate cleaved product in the promotionof the synthesis of nitriles from aldoximes: a mechanistic perception

pp 4397–4400

Dharm Dev, Nani Babu Palakurthy, Nitesh Kumar, Bhubaneswar Mandal*

R1 NOH

DBU, DCM, rt, N2

RSO3XY

R1 = aromatic, aliphaticR = CH3-C6H4, 2-NO2-C6H4, 4-NO2-C6H4, 2, 4-diNO2-C6H4

R1 N

Contents / Tetrahedron Letters 54 (2013) 4347–4355 4349

An alternative reduction course of the spiroketal side chain of steroid sapogenins induced by the presence of a23E-benzylidene moiety

pp 4401–4405

Manuel A. Ramos-Enríquez, Margarita Romero-Ávila, Marcos Flores-Álamo, Martín A. Iglesias-Arteaga*

NaBH3CNAcOH

a) 5α, 25R; R1= H, R2 = CH3b) 5β, 25S; R1= CH3, R2 = H

O

O

R1

R2

AcOH

+

O

R1

OHR2

H

2

O

O

R1

R2

3

O

R1

OHR2

H4

1

normal course

abnormal course

over reduction

SM Products (Yield %)1a 2a (64) 3a (32) 4a (0)1b 2b (52) 3b(18) 4b (4)

A macrolactonisation approach to the cembrane carbocycle of bielschowskysin pp 4406–4408

Eugene G. Yang, Karthik Sekar, Martin J. Lear*

O

OOH

O

O

TBDPSO

Cl O

OO

OH

OHHH

OO

H

HO

OAcbielschowskysin (1)

1

4

10 11

8

C

O

OOH

O

O

TBDPSO

TBSO OH

I

12

1

4

10

11

8

12 H

-acylketene intermediate

predisposes conformationfor cyclization

β

Synthesis of novel glycopeptidomimetics via Nb-protected-amino alkyl isonitrile based Ugi 4C reaction pp 4409–4413

Basavalingappa Vasantha, Girish Prabhu, Hosmani Basavaprabhu, Vommina V. Sureshbabu*

PgHN

R1

NC R2 CHO H2N COOMeR3

PgHN

R1HN

NO

R2

COOMe

R3

OO

O O

OO

PgHN

R1HN

NO

R2

COOMe

R3

O

NHO

OBzBzO

BzO

BzOO

AcOAcO

AcON N

NOAc

PgHN

R1HN

NO

R2

COOMe

R3

O

5a-5c 6a 7a-7c

Sugar acid 1 Sugar acid 3Sugar acid 2

+ +

Pg1HN

R1HN

NO

R2

NHPg2O

R3

O

OAc

OAc

OAcOAc12a, b

Pg1HN

R1HN

NO

R2HN

O

R3

O

OAc

OAc

OAcOAc

ONHPg2

R4

13a, b

4

Ugi-4C reaction employing Nb-protected-amino alkyl isonitrile, amino acid ester, aldehyde, and glycosyl acid has resulted in novel glycosylatedpeptidomimetics. Further, the protocol has been extended for the synthesis of N,N0-orthogonally protected glycosylated peptidomimetics as well.

Iron-catalyzed indirect hydration of alkynes in presence of methanesulfonic acid pp 4414–4417

Jungmin Park, Jihee Yeon, Phil Ho Lee, Kooyeon Lee*

R1 R2

FeCl2 4H2O (5 mol%)MsOH (1.1 equiv.)

DCE, 60 oC R1 R2O

or R1 R2

O

R1, R2 = H, alkyl, aryl, halide 16 examples

49 - 96% yields

4350 Contents / Tetrahedron Letters 54 (2013) 4347–4355

Novel ring transformation of mesoionic oxazoles into 2(1H)-pyrazinones by the reaction with TosMIC pp 4418–4421

Ryosuke Saijo, Ken-ichi Kurihara, Kazuki Akira, Hidemitsu Uno, Masami Kawase*

N

OO

R2

R1COCF3

N

NR1

OR2

Ts

C, DBU

- CO2

TsCH2N O2,

An efficient synthesis of coumarin- and quinolone-annulated thiazole derivatives via ligand-free iron(III)-catalyzed coupling followed by acid-promoted condensation

pp 4422–4424

K. C. Majumdar*, Debankan Ghosh

X N

SO

X NH

BrO

(i) FeCl3 (10 mol%),DMF, 120 oC

OR

R+ Na2S.xH2O

ii) HCl, rt

X = O, NMe, NEtR = alkyl or aryl group

New synthesis of a selective estrogen receptor modulator using an enatioselective phosphine-mediated 2+3cycloaddition

pp 4425–4428

Debra J. Wallace*, Robert A. Reamer

MeO

O

O

MeO

O

O

2+3cycloadditon

HO

O

Cl

Cl

PL3

Development of a scalable synthesis of P7C3-A20, a potent neuroprotective agent pp 4429–4431

Jacinth Naidoo, Christopher J. Bemben, Shawn R. Allwein, Jue Liang, Andrew A. Pieper, Joseph M. Ready*

Contents / Tetrahedron Letters 54 (2013) 4347–4355 4351

Reagent-free synthesis of 2,3,4-polysubstituted tetrahydroquinolines: application to the formal synthesis of(±)-martinellic acid and martinelline

pp 4432–4434

Zhouting Rong, Qingjiang Li, Wenhan Lin*, Yanxing Jia*

NH

HN

HN

NNH

NH

HO2C

NHmartinellic acid

+Reagent free

THF, 60 °CNH2

R1

NH

NHR2

OR2

R1

R1

R2

12 examplesup to 98% yield

AlCl3–NaI assisted cleavage of polymer-bound esters with concomitant amine coupling and azido-reductivecyclization: synthesis of pyrrolobenzodiazepine derivatives

pp 4435–4441

Ahmed Kamal*, S. Prabhakar, Nagula Shankaraiah, Nagula Markandeya, P. Venkat Reddy, Vunnam Srinivasulu, Manda Sathish

H3CO

O

N

X

O

Y

Z

X = N3Y = CO2CH3 / CHOZ = H, OMs, OTs

O

n = 4,5

AlCl3-NaI

H3CO

O

N

X Y H

O

N

OR1

R2

n

O

n

n = 4,5Z

X, Y = NH-C=O / N=CHZ = H, OMs, OTs

Diversity Oriented Synthesis

SLE method

Facile chemoselective carbonyl allylation of chalcones with allyltributylstannane catalyzed by CuI pp 4442–4445

Pabitra Kumar Kalita, Prodeep Phukan*

O

R2R1

OH

R2R1SnBu3

CuI (25 mol %),K2CO3

DMF, 70 oC+

R1 = H, Cl, F, Br, OMe, Me, Me2N etc.; R2 = H, F

A new isoluminol reagent for chemiluminescence labeling of proteins pp 4446–4450

Alessandro Palmioli, Marco Crisma, Cristina Peggion, PierNatale Brusasca, Davide Zanin, Andrea Dal Corso, Paolo Ingallinella,Francesco Peri*

4352 Contents / Tetrahedron Letters 54 (2013) 4347–4355

A facile and convenient way to functionalized trifluoromethylated spirocyclic[indole-3,4-pyrano[2,3-c]pyrazole]derivatives

pp 4451–4455

Xiaoqing Liu, Xiaoling Xu, Xu Wang, Wenxin Yang, Qun Qian, Min Zhang, Liping Song*, Hongmei Deng, Min Shao

N

O

OCN

R3F3C OEt

O OR1

R2

PiperidineEtOH, ref

R1 = H, Cl, Br, CH3, NO2 R2 = H, CH3 R3 = CN, CO2EtCONH2

R4 = H, Ph

1 2 3 4 5

+ + + R4-NHNH2

N

O

R1

R3

H2N

O

NN

CF3

R2

R4

Luminescent molecular solar concentrators made of multi-Bodipy dyes pp 4456–4462

Antoine Mirloup, Pascal Retailleau, Raymond Ziessel*

N N

S

O

B

O

O

O

O

I

N B NF F

S

SNN

S

B

O

O

O

O

S

OO

O

Direct conversion of glycerol into formic acid via water stable Pd(II) catalyzed oxidative carbon–carbonbond cleavage

pp 4463–4466

Prasanna Pullanikat, Joo Ho Lee, Kyung Soo Yoo, Kyung Woon Jung*

HO OHOH Pd(II) Catalyst

N

N

O

N

OMe

ClPd

CH3

H2O2, 60 oC61%

HCO2H

Construction of functionalized tricyclic dihydropyrazino-quinazolinedione chemotypes via an Ugi/N-acyliminiumion cyclization cascade

pp 4467–4470

Steven Gunawan, Christopher Hulme*

F O

OH

NO2

CNOEt

OEt

NH2

MeO OMeR1

CHO R2NH2

NHN

OEt

F

NO2

O R1

O

OEt

MeO OMe

MeOHN

NN

HN

OO

R1

R2H

HR3

R4

24 (+)

R3Br

R4Cl

Herein, we report the production of a diversified tricyclic scaffold in 3 synthetic operations involving an Ugi multicomponent reaction followed by an N-acyliminium ioncyclization cascade. Further functionalization of the biologically appealing tricyclic core 24 was achieved via sequential N-alkylation and N-acylation and/or sulfonation.

Contents / Tetrahedron Letters 54 (2013) 4347–4355 4353

Toward the chemoenzymatic synthesis of heparan sulfate oligosaccharides: oxidative cleavage of p-nitrophenylgroup with ceric ammonium salts

pp 4471–4474

Chao Cai, Lingyun Li, Cate Harvey, Jian Liu, Robert J. Linhardt*

Solid-supported ortho-iodoarylboronic acid catalyst for direct amidation of carboxylic acids pp 4475–4478

Nicolas Gernigon, Hongchao Zheng, Dennis G. Hall*

BOHHO

I

ONH

R1 OH

O

+H2NR2

(1.1 equiv)

(1.0 equiv)

14 (10 mol%)

4A mol. sievesCH2Cl2, rt

R1 NHR2

O

amide product

Odouble

evaporation

recyclable catalyst 14

4A m.s.

New strategy toward the diverted synthesis of oxidized abietane diterpenes via oxidation of 6,7-dehydroferruginolmethyl ether with dimethyldioxirane

pp 4479–4482

I. Córdova-Guerrero*, Lucía San Andrés, Alma E. Leal-Orozco, José M. Padrón, J. M. Cornejo-Bravo, Francisco León*

H

OMe

11

H

OMe

OHOH

H

OMe

O

12 15

DMDO DMDO

Highly efficient synthesis of aryl and heteroaryl trifluoromethyl ketones via o-iodobenzoic acid (IBX) pp 4483–4486

Huicheng Cheng, Yu Pei, Faqiang Leng, Jingya Li, Apeng Liang, Dapeng Zou*, Yangjie Wu, Yusheng Wu*

Ar CF3

O

Ar CF3

OH

Ar CF3

OH

Ar

O (1) cat. K2CO3 / DMF, rt

(2) H3O+ or TBAFH

+I

O

O

OHO+I

O

O

OH

(1) EtOAc; reflux

(2) Filtration

(IBX) (IBA)

+ Si CF3

Oxone

35 ExamplesUp to 99% YieldsRecylable Oxidant

4354 Contents / Tetrahedron Letters 54 (2013) 4347–4355

TiCl4 mediated preparation of (E)-non-conjugated homoallylic alcohols with a-substituted allylsilanes pp 4487–4490

Aymara M. M. Albury, Michael P. Jennings*

Me3Si

RR = Ph or C6H13

R'

OH

R

TiCl4R'CHO

E/Z : 8-20/1

2-Arylvinylpyrimidines versus 4-arylvinylpyrimidines: synthesis and comparison of the optical properties pp 4491–4496

Sylvain Achelle*, Françoise Robin-le Guen

N N

EDG

N N

EDG

Versus

Fluorescence

Halochromism

EmissionSolvatochromism

*Corresponding authorSupplementary data available via SciVerse ScienceDirect

Abstracted/indexed in: AGRICOLA, Beilstein, BIOSIS Previews, CAB Abstracts, Chemical Abstracts, Chemical Engineering andBiotechnology Abstracts, Current Biotechnology Abstracts, Current Contents: Life Sciences, Current Contents: Physical,Chemical and Earth Sciences, Current Contents Search, Derwent Drug File, Ei Compendex, EMBASE/Excerpta Medica, Medline,PASCAL, Research Alert, Science Citation Index, SciSearch. Also covered in the abstract and citation database SciVerse Scopus�.Full text available on SciVerse ScienceDirect�

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ISSN 0040-4039

Contents / Tetrahedron Letters 54 (2013) 4347–4355 4355