hoaÙ hoÏc hÖÕu cÔ organic chemistry chÖÔng 6 alkanes
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HOAÙ HOÏC HÖÕU CÔHOAÙ HOÏC HÖÕU CÔOrganic ChemistryOrganic Chemistry
CHÖÔNG 6Alkanes
GIÔÙI THIEÄU MOÂN HOÏC1.: HOÙA HOÏC HÖÕU CÔ
(ORGANIC CHEMISTRY)1.Soá tín chæ: 3 (3.1.6)2.Maõ soá moân hoïc: 6060103.Noäi dung toùm taét moân hoïc:
• Lieân keát- Caáu taïo-caáu truùc hôïp chaát höõu cô
• Phaûn öùng vaø cô cheá phaûn öùng höõu cô
• Caùc phöông phaùp cô baûn toång hôïp caùc hôïp chaát höõu cô
• Tính chaát lyù hoùa caùc hôïp chaát höõu cô
• ÖÙng duïng: Hôïp chaát maøu, hôùp chaát coù höông, chaát hoaït ñoäng beà maët, chaát noå, chaát dieät khuaån-coân truøng, chaát kích thích taêng tröôûng….
Unbranched AlkanesUnbranched Alkanes
““Straight-chain” alkanes have a zig-zag Straight-chain” alkanes have a zig-zag orientation when they are in their most orientation when they are in their most straight orientationstraight orientation
Branched AlkanesBranched Alkanes
Branched Branched alkanes have alkanes have at least one at least one carbon which carbon which is attached to is attached to more than more than two other two other carbonscarbons
Physical PropertiesPhysical Properties
Boiling points of unbranched alkanes Boiling points of unbranched alkanes increase smoothly with number of carbonsincrease smoothly with number of carbons• CHCH44-C-C44HH1010: gazes: gazes
Melting points roughly increase with Melting points roughly increase with number of carbonsnumber of carbons• CC55HH1212-C-C1717HH3636: liquids: liquids
Low polarityLow polarity• Insoluble in waterInsoluble in water• Soluble in non-polar solventsSoluble in non-polar solvents
Physical PropertiesPhysical Properties
The boiling point increases The boiling point increases with the length of the chainwith the length of the chain
Structural IsomersStructural Isomers
Constitutional isomers have the same molecular Constitutional isomers have the same molecular formula but different connectivity of atomsformula but different connectivity of atoms
IUPAC Rules for Alkanes and IUPAC Rules for Alkanes and Alkyl HalidesAlkyl Halides
1.1. Select the longest continuous chainSelect the longest continuous chainBasic nameBasic name
2.2. Number the carbons form the end nearest the first branchNumber the carbons form the end nearest the first branchNumberingNumbering
3.3. Locate substituents on the main chainLocate substituents on the main chainLocationLocationIf two substituents on the same carbon, use the number If two substituents on the same carbon, use the number
twicetwice4.4. Identify substituents Identify substituents
IdentificationIdentificationif more than one use “di”, “tri”, “tetra”,…if more than one use “di”, “tri”, “tetra”,…
5.5. Put substituents in alphabetical orderPut substituents in alphabetical order6.6. Separate numbers from letters using dashes and place the Separate numbers from letters using dashes and place the
basic name at the end.basic name at the end.
DANH PHAÙPhttp://www.acdlabs.com/iupac/nomenclature/
RadicalsRadicals
CHCH33- - methyl (Me)methyl (Me) CHCH33-CH-CH22-- ethyl (Et)ethyl (Et) CHCH33-CH-CH22-CH-CH22-- n-propyl (n-propyl (nnPr)Pr) (CH(CH33))22-CH--CH- iso-propyl (iso-propyl (iiPr)Pr) CHCH33-CH-CH22-CH-CH22-CH-CH22-- n-butyl (n-butyl (nnBu)Bu) (CH(CH33))22-CH-CH-CH-CH22-- iso-butyl (iso-butyl (iiBu)Bu) (CH(CH33))33-C--C- tert-butyl (tert-butyl (ttBu)Bu) CC66HH55-- phenyl (Ph)phenyl (Ph)
DANH PHAÙP
DANH PHAÙP
AlkanesAlkanes
DANH PHAÙP
DANH PHAÙP
LAI HOÁ sp3
Nobel prize 1969Nobel prize 1969
Sir Derek Barton (UK, 1918-1998)Sir Derek Barton (UK, 1918-1998) Odd Hassel (Norway, 1897-1981)Odd Hassel (Norway, 1897-1981) for their contributions to the development of the for their contributions to the development of the
concept of conformation and its application in concept of conformation and its application in chemistry"chemistry"
Sir Derek BartonSir Derek Barton
Nobel Lecture starting with this citation:Nobel Lecture starting with this citation:
StereoisomersStereoisomers ConformersConformers
• Isomers resulting from the free rotation of a single bondIsomers resulting from the free rotation of a single bond Ethane: Ethane: staggered conformationstaggered conformation (C-H bonds on (C-H bonds on
adjacent carbons as far apart from each other as adjacent carbons as far apart from each other as possible)possible)
The drawing to the right is called a Newman The drawing to the right is called a Newman projectionprojection
eclipsed conformation:eclipsed conformation: all C-H bonds on adjacent all C-H bonds on adjacent carbons directly on top of each othercarbons directly on top of each other
The Newman RepresentationThe Newman Representation
The Newman RepresentationThe Newman Representation
Staggered and eclipsedStaggered and eclipsed
Staggered
Eclipsed
3D Formulas3D Formulas
H
H H
HH
H
The Torsional StrainsThe Torsional Strains
Staggered: most stable
Eclipsed: least stable
Ethane conformationEthane conformation the staggered conformation is more stable the staggered conformation is more stable
than eclipsed by 12 kJ molthan eclipsed by 12 kJ mol-1-1
ÑOÀNG PHAÂN CAÁU DAÏNG
ÑOÀNG PHAÂN CAÁU DAÏNG
ButaneButane
Anti most stableAnti most stable
Fully eclipsed most unstableFully eclipsed most unstable
H H
H3C
H H
H3C
CH3
H3C
H
H
H
H
H
H
CH3
H H
H3C H3C CH3
HHH H
ButaneButane
Gauche less stable than antiGauche less stable than anti
Eclipsed less unstable than fully eclipsedEclipsed less unstable than fully eclipsed
H CH3
H
H H
H3C
H
H3C
H
CH3
H
H
H
CH3
H
H H
H3C H3C H
CH3HH H
ButaneButane
H H
H3C
H H
H3C
H
CH3
H
H H
H3C
H
H CH3
H H
H3C
H
H
CH3
H H
H3C
H
HH3C
H H
H3C
H
H3C
H
H H
CH3
H H
H3C
H H
H3C
ButaneButane
ÑOÀNG PHAÂN CAÁU DAÏNG
ÑOÀNG PHAÂN CAÁU DAÏNG
Preparation of AlkanesPreparation of Alkanes
Catalytic hydrogenation of alkenes Catalytic hydrogenation of alkenes and alkynesand alkynes
Preparation of AlkanesPreparation of Alkanes
Preparation of AlkanesPreparation of Alkanes
Preparation of AlkanesPreparation of Alkanes
Preparation of AlkanesPreparation of Alkanes The Kolbe reactionThe Kolbe reaction is the electrosynthesis of is the electrosynthesis of
hydrocarbons via electrooxidation of carboxylic hydrocarbons via electrooxidation of carboxylic acids.acids.
Preparation of AlkanesPreparation of Alkanes
Preparation of AlkanesPreparation of Alkanes
Reduction/OxidationReduction/Oxidation ReductionReduction: gain of hydrogen, loss of oxygen, …: gain of hydrogen, loss of oxygen, …
• Level of oxidation decreasesLevel of oxidation decreases OxidationOxidation: gain of oxygen, loss of hydrogen, …: gain of oxygen, loss of hydrogen, …
• Level of oxidation increasesLevel of oxidation increases Hydrogenation: reduction of alkenes and alkynesHydrogenation: reduction of alkenes and alkynes
Syn Addition in Heterogeneous Syn Addition in Heterogeneous CatalysisCatalysis
hydrogen and alkene adsorbed to hydrogen and alkene adsorbed to the catalyst surfacethe catalyst surface
Syn AdditionSyn Addition
Both hydrogens add to the same Both hydrogens add to the same face of the alkene (syn addition)face of the alkene (syn addition)
ExamplesExamples
1,2-dimethylcyclohexene1,2-dimethylcyclohexene
Reduction of Alkyl HalidesReduction of Alkyl Halides
With metalsWith metals
Paul Sabatier (1854-1941)Paul Sabatier (1854-1941)
Nobel Prize 1912Nobel Prize 1912 "for his method of "for his method of
hydrogenating organic hydrogenating organic compounds in the presence of compounds in the presence of finely disintegrated metals finely disintegrated metals whereby the progress of whereby the progress of organic chemistry has been organic chemistry has been greatly advanced in recent greatly advanced in recent years"years"
University of Toulouse, University of Toulouse, FranceFrance
Victor GrignardVictor Grignard Nobel prize 1912Nobel prize 1912 "for the discovery of the so-"for the discovery of the so-
called Grignard reagent, which called Grignard reagent, which in recent years has greatly in recent years has greatly advanced the progress of advanced the progress of organic chemistry" organic chemistry"
University of Nancy, FranceUniversity of Nancy, France
Ph. Barbier, University of Ph. Barbier, University of Lyon, FranceLyon, France
Barbier reactionBarbier reaction
Grignard ReagentsGrignard Reagents
Grignard reagent preparationGrignard reagent preparation Reaction of organic halides with Reaction of organic halides with
magnesium turnings in ether (DRY magnesium turnings in ether (DRY ether)ether)
Killed with water: form alkanesKilled with water: form alkanes
Grignard ReagentsGrignard Reagents
Strongly react with waterStrongly react with water Grignard reagents behave as if they were Grignard reagents behave as if they were
carbanions and they are therefore very carbanions and they are therefore very strong basesstrong bases
R rich in electronR rich in electron
Grignard ReagentsGrignard Reagents
Formally: conversion of halides to Formally: conversion of halides to hydrogenhydrogen
The Grignard reaction: addition of The Grignard reaction: addition of Grignard reagents to carbonylsGrignard reagents to carbonyls
Elias J. CoreyElias J. Corey Nobel Prize 1990Nobel Prize 1990 "for his development of the theory "for his development of the theory
and methodology of organic and methodology of organic synthesis" synthesis"
Harvard University, USAHarvard University, USA
Many Corey reactions…Many Corey reactions…• (Corey-Winter, Corey-Chakovsky, (Corey-Winter, Corey-Chakovsky,
Corey-Bakshi-Shibata, Corey-Corey-Bakshi-Shibata, Corey-Fuchs, Corey-Kim, …)Fuchs, Corey-Kim, …)
… … and reagentsand reagents• PDC, PCC, …PDC, PCC, …
OrganometallicsOrganometallics
Organolithium reagentsOrganolithium reagents
Organocuprate reagents (Gilman Organocuprate reagents (Gilman reagents)reagents)
Corey-Posner, Whitesides-Corey-Posner, Whitesides-HouseHouse
Coupling of two alkyl halides Coupling of two alkyl halides Organocuprate reagentsOrganocuprate reagents
Henry GilmanHenry Gilman Henry Gilman (1893-1986), Iowa Henry Gilman (1893-1986), Iowa
State UniversityState University Talking about his research as a Talking about his research as a
student: 'A sheer delight. Here I student: 'A sheer delight. Here I was, just a senior. We'd work at was, just a senior. We'd work at night until 11 or 12 o'clock, night until 11 or 12 o'clock, without any compulsion--just for without any compulsion--just for the joy of it.'the joy of it.'
Post doc at Harvard with Kohler Post doc at Harvard with Kohler who is credited with having who is credited with having introduced the use of the introduced the use of the Grignard reagent to the U.S.A.Grignard reagent to the U.S.A.
Lithium dialkylcuprate are called Lithium dialkylcuprate are called Gilman ReagentsGilman Reagents
Posner, Whitesides and HousePosner, Whitesides and House
Georges M. Whitesides, Georges M. Whitesides, Harvard UniversityHarvard University• Material ScienceMaterial Science
Gary H. Posner, Johns Gary H. Posner, Johns Hopkins UniversityHopkins University• Organic ChemistryOrganic Chemistry
H O. House, Georgia H O. House, Georgia Institute of technologyInstitute of technology
ExamplesExamples