有機(jī)化學(xué)英文課件chpt12

1、第十二章胺類AminesOrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversityAmines are organic derivatives of ammonia in the same way that alcohols and ethers are organic derivatives of water.H2OROHR2OWateralcoholetherNH3RNH2R2NH R3Nammonia aminesOrganicOrganic ChemistryChemistry12.1 胺的結(jié)構(gòu)和命名Xiamen

2、Xiamen UniversityUniversityStructure and Nomenclature of AminesOrganicOrganic ChemistryChemistryStructureAmines are classified as primary (RNH2), secondary (R2NH) , or tertiary (R3N), depending on the number of organic substituents attached to nitrogen.XiamenXiamen UniversityUniversityCH3NH2(CH3)2NH

3、(CH3)3Nmethylaminedimethylaminetrimethylamineprimarysecondarytertiary伯胺(一級胺) 仲胺(二級胺) 叔胺(三級胺)OrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversityNote Note that this usage of the terms primary, secondary, and tertiary is different from our previous usage. When we speak of a tertiary alco

4、hol or alkyl halide, we refer to the degree of substitution at the alkyl carbon atom. When we speak of a tertiary amine, however, we refer to the degree of substitution at the nitrogen atom.OrganicOrganic ChemistryChemistryCH3CH3CH3CH3COHCH3NCH3CNH2CH3CH3CH3tert-Butyl alcoholTrimethylaminetert-Butyl

5、amine(a tertiary alcohol)(a tertiary amine) (a primary amine)XiamenXiamen UniversityUniversityIn secondary and tertiary amines, the alkyl groups may be the same or different.(CH3CH2)2NH CH3CH2NHCH3 CH3NNCH3CH3OrganicOrganic ChemistryChemistry Compounds with four groups attached to nitrogen are also

6、known, but the nitrogen atom must carry a positive charge. Such compounds are called quaternary ammonium salts.XiamenXiamen UniversityUniversityRR XRN季銨鹽A quaternary ammonium saltROrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversityNomenclature of Amines Primary amines are named in the

7、 IUPAC system in several ways depending on their structure. For simple amines, the suffix -amine is added to the name of the alkyl substituent. Alternatively, the suffix amine can be used in place of the final e in the name of the parent compound.OrganicOrganic ChemistryChemistryXiamenXiamen Univers

8、ityUniversityCH3CH3CNH2NH2CH3tert-ButylamineCyclohexylamineNH2CH3NH2NH2CH31,4-Butanediamine4,4-DimethylcyclohexanamineOrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversityAn -NH 2 group, when not the principal group, is named by the prefix amino-.CO2HH2NCO2HNH2NH22-Aminobutanoic acid2,6

9、-Diaminobenzoic acidONH24-Amino-2-butanoneOrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversity Symmetrical secondary and tertiary amines are named by adding the prefix di- or tri- to the alkyl group.HN(CH3CH2)3NDiphenylamineTriethylamineOrganicOrganic ChemistryChemistry Unsymmetrically

10、 substituted secondary and tertiary amines are named as N-substituted primary amines. The largest alkyl group is chosen as the parent name, and the other alkyl group are considered N-substituents on the parent (N since theyre attached to nitrogen).XiamenXiamen UniversityUniversityCH3N(CH3)2NCH2CH3N,

11、N-Dimethylpropylamine N-Ethyl-N-methylcyclohexylamineOrganicOrganic ChemistryChemistry12.2 胺的物理性質(zhì)XiamenXiamen UniversityUniversityPhysical properties of AmineOrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversityPhysical Properties of Amines Amines are highly polar and therefore have hig

12、her boiling points than alkanes of equivalent molecular weight have. Like alcohols, amines with RBr RCl1 RX 2 RXOrganicOrganicGabriel SynthesisOKOHORXChemistryChemistryNHOEtOHH+ or OHN KOCO2HRNH+XiamenXiamen UniversityUniversityOH2ON ROH2NNH2 EtOH2CO2HORNH2+NHNHOOrganicOrganic ChemistryChemistryXiam

13、enXiamen UniversityUniversityPreparing Amines from AlcoholsAl2O3ROH + NH3 RNH2 + R2NH + R3N + H2O , 壓力NH3ROH + TsCl ROTs RNH2 + TsOOrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversityOPhPhTsClHOTsN KHOHOPy.CH3CH3OPhH2NNH2PhNHH2NHEtOHOCH3CH3OrganicOrganic ChemistryChemistryReduction of

14、Nitro compoundsCH3Fe, FeSO4NaOHCH3HOCH2CNO2HOCH2CNH2H2O-H2SO4CH3CH3XiamenXiamen UniversityUniversityHR NO2 R NH2M / H+ : Zn / HCl , Fe / HCl , Sn / HCl ,H 2 / CatalystNa2S , NaSH, (NH4)HS , (NH4)2SOrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversityReduction of Nitriles , Amides and Ox

15、imesR CNRCONH2HRCNOHR CH2NH2RHLiAlH4 , B2H6 , H2 / CatalystOrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversityReductive Amination of Ketones and AldehydesC6H5CHO + NH3(excess)H2 / NiC H CH NHEtOH6522RH2 / NiRCO + NH3(excess)CHNH2EtOHRR+ NH3(excess)H2 / NiEtOHNH2OOrganicOrganic Chemist

16、ryChemistryMechanismMechanismMechanismRRCO + NH3(excess)CNHRRXiamenXiamen UniversityUniversityH2 / NiRCHNH2EtOHROrganicOrganic ChemistryChemistryLeukartLeukart ReactionReaction Reductive alkylation of ammonium (or amine) salts of formic acid by aldehydes or ketones:XiamenXiamen UniversityUniversityH

17、CO2NH4RCHO RCH 2NH2OrganicOrganic ChemistryChemistryEschweilerEschweiler-ClarkeClarke ReactionReaction The reductive methylation of primary or secondary amines employing formaldehyde and formic acid:XiamenXiamen UniversityUniversityHCO2H(excess)RNH2 + CH2O RN(CH3)2OrganicOrganic ChemistryChemistryXi

18、amenXiamen UniversityUniversityPreparation of Amines from Carboxylic Acids and Their DerivativesH O C N O CN H氰酸異氰酸O CNR異氰酸酯 isocyanateR N nitrene (氮賓)ORCN acyl nitrene (?；e)OrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversityHofmannHofmann RRearrangementearrangement An unsubstitued a

19、mide is treated with Br2/NaOH (NaOBr) to give a primary amine that has one carbon fewer than the starting amide.OBr2H2ORNCORCNHRNH22NaOHCO2NaOBr(1)(CH3)3CCH2CONH2 (CH3)3CCH2NH294%OCO2HNaOClH+(2)NHNaOHNH2OOrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversityMechanismMechanismMechanismOOH

20、OOHOR C N BrR CNH2 + Br2R CNHBrBrOH2OOH2R CNR N C OR NC OOHOCO2R NH C OHRNH2R NC OHOrganicOrganic ChemistryChemistryCurtiusCurtius RRearrangementearrangement Formation of isocyanates by thermal decomposition of acyl azides:XiamenXiamen UniversityUniversityOOR C Cl + NaN3 R C N3 R N C OH2OCO2 RNH2Org

21、anicOrganic ChemistryChemistryXiamenXiamen UniversityUniversityONaNOCHCl33(CH3)2CHCH2CN3(1)(CH ) CHCH CCl3 22(CH ) CHCHNCOH2O(CH3)2CHCH2NH223 2CO2(70%)(2)BrBrH2OCCCO2CN3NOCOCO(60%)OrganicOrganic ChemistryChemistryMechanismMechanismMechanismOOR CN N NR C NR N C ON2XiamenXiamenH2ORNH2UniversityUnivers

22、ityCO2OrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversitySchmidtSchmidt RearrangementRearrangementOORCOH+HN3 H2SO4RCN3 RNCOH2ORNH2CO2CO2HNH2+ HN3H2SO46080%OrganicOrganic ChemistryChemistryMechanismMechanismMechanismOOR CN N NR C NR N C ON2XiamenXiamenH2ORNH2UniversityUniversityCO2Orga

23、nicOrganic ChemistryChemistryXiamenXiamen UniversityUniversity12.4 胺的堿性Amine BasicityOrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversityStructure and Bonding in Amine The bonding in amines is similar to the bonding in ammonia. The nitrogen atom is sp3 hybridized, with the three substi

24、tuents occupying three corners of a tetrahedron and the nitrogen nonbonding lone pair of electrons occupying the forth corner.sp3 hybridizedN CH3 CH3CH3OrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversityBasicity Because of the nitrogen lone pair of electrons, amines are both basic and

25、 nucleophilic. Amines are much more basic than alcohols, ethers, or water. Some amines are stronger and some are weaker in base strength. Measure of the base strength pKb or pKaOrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversityBasicity of Some AminesAminepKbpKaNH34.769.26MeNH23.3810.

26、62EtNH23.3610.64t-BuNH23.3210.68Me2NH3.2710.73Et2NH3.0610.94Me3N4.219.79Et3N3.2510.75OrganicOrganic ChemistryChemistryCH3(CH2)9NH2 + HCl CH3(CH2)9NH3 ClXiamenXiamen UniversityUniversity(CH3)2CHTHF(CH3)2CHNH + n-C4H9LiNLi(CH3)2CH(CH3)2CHDiisopropylamineButyllithiumLithium diisopropylamideLDAOrganicOr

27、ganic ChemistryChemistryXiamenXiamen UniversityUniversity12.5 胺的反應(yīng)Reactions of AminesOrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversityAcylation Primary and secondary (but not tertiary) amines can be acylated by reaction with acid chlorides or acid anhydrides to yield amides.ONH3RNH2

28、COPyridineORNH2 + RRNHRCCClOR2NHRNR2COrganicOrganic ChemistryChemistryXiamenXiamen UniversityUniversityHinsberg Reaction If a sulfonyl chloride, RSO2Cl , is used as the acylating agent, a sulfonamide is produced.OORSClRSNHRO O Sulfonyl chloride SulfonamideOrganicOrganic ChemistryChemistryXiamenXiame

29、n UniversityUniversityORNH2PhSNHROOPyridineOR2NH+ PhPhSNR2SClOOOPhNR3R3NSOOPhH2OSOH + R3NOOrganicOrganic ChemistryChemistryQuaternary Ammonium Compounds Quaternary ammonium salt25(CH ) N + CHI(C2H5)3N+CH3 I -25 33etherTriethylmethylammonium iodideXiamenXiamen UniversityUniversity Quaternary ammonium

30、 hydroxideAg2O(C2H5)3N+CH3 I -(C2H5)3N+CH3 OH -Triethylmethylammonium hydroxideOrganicOrganic ChemistryChemistry(CH3)4N+ Cl -(CH3CH2CH2CH2)4N+ Br -Tetramethylammonium chloride Tetrabutylammonium bromide四甲基氯化銨四丁基溴化銨(氯化四甲基銨)XiamenXiamen UniversityUniversityCH3CH3CO2CH2CH2NCH3 BrCH3Acetylcholine bromide溴化乙酰膽堿OrganicOrganic ChemistryChemistryHofmannHofmann EliminationEliminationCH3(CH2)5NH2CH3I CH3(CH