厦门大学化学化工学院：《有机化学》课程教学资源（课件讲稿，双语版）第六章 离子反应 —卤代烃的亲核取代和消除反应（6.15-6.19）Organic Synthesis Functional

ORGANIC CHEMISTRY Chapter 6 6.15 Organic Synthesis Functional Group Transformations Using SN2 Reactions Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 6 6.15 Organic Synthesis: Functional Group Transformations Using SN2 Reactions

ORGANIC CHEMISTRY Chapter 6 o SN2 reactions are highly useful in organic synthesis because they enable use to convert one functional group into another functional group transformation(functional group interconversion) Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 6 SN2 reactions are highly useful in organic synthesis because they enable use to convert one functional group into another —— functional group transformation (functional group interconversion)

ORGANIC CHEMISTRY Chapter 6 RI Alkyl iodide NaoH roH Alcohol Natch ROCH ether Nao-C-CH3 RX Ro-C-CH ester or 20 NaoNO, R=Me.1° ChroNO Methyl nitrate XCI. Br NaCN or I ron Nitrile a RN3 alkyl azide Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 6 NaO C O CH3 RO C O RX CH3 NaI NaOH NaOCH3 NaONO2 NaCN NaN3 RI ROH ROCH3 CH3ONO2 RCN RN3 Alkyl iodide Alcohol Ether Ester Methyl nitrate Nitrile Alkyl azide R= Me, 1° or 2° X= Cl, Br or I

ORGANIC CHEMISTRY Chapter 6 Nash RSH Thiol NascN rscn Alkyl thiocyanate NaCH(CO2CH3)2 RCH(CO2CH3)2 Dimethyl alky malonate R-X NaC≡C-C3,RC=C- CH Alkyne NH RNH Br Alkylammonium bromide N(CH3)3 R(CH33NBr P(CH3)3 Alkyltrimethylammonium bromide R(CH3)3 PBr Alkyltrimethylphosphonium bromide Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 6 NaC C RC C CH3 CH3 X NaSH NaSCN NaCH(CO2CH3)2 RSH RSCN RCH(CO2CH3)2 RNH3Br R(CH3)3NBr NH3 N(CH3)3 P(CH3)3 R(CH3)3PBr Thiol Alkyl thiocyanate Dimethyl alkylmalonate Alkyne Alkylammonium bromide Alkyltrimethylammonium bromide Alkyltrimethylphosphonium bromide R

ORGANIC CHEMISTRY Chapter 6 AgNO R-X R-ONO2 +AgX EtoH CHCl Room Tempt. heat CHo-CHCHoCl AgCl↓ instantly CH3)3CCI (CH3)2CHCI AgNO3 AgCl 2 or 3 minium EtOH CH3 CH2 CH2CI AgCI CHO-CHC cl Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 6 R X R ONO2 + AgX AgNO3 EtOH CH2Cl CH2 CHCH2Cl CH2 CHCl Cl AgCl instantly AgCl 2 or 3 miniums Room Tempt. heat (CH3)3CCl (CH3)2CHCl CH3CH2CH2Cl AgNO3 EtOH AgCl

ORGANIC CHEMISTRY Chapter 6 6.16 Elimination reactions of Alkyl Halides 卤代烃的消除反应 Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 6 6.16 Elimination Reactions of Alkyl Halides 卤代烃的消除反应

ORGANIC CHEMISTRY Chapter 6 o Another characteristic of alkyl halides is that undergo elimination reactions. In an elimination reaction the fragments of some molecule(yz) are removed (eliminated )from adjacent atoms of the reactant This elimination leads to the introduction of a multiple bond Elimination C-C YZ Y Z Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 6 Another characteristic of alkyl halides is that undergo elimination reactions. In an elimination reaction the fragments of some molecule (YZ) are removed (eliminated) from adjacent atoms of the reactant. This elimination leads to the introduction of a multiple bond: C Y C Z C C Elimination YZ

ORGANIC CHEMISTRY Chapter 6 616 A Dehydrohalogenation(脱卤化氢) KOH EtOH RCHoCHo-X RCH-CH KOH EtOH RCH2CH-X RC≡CH Reactivity: R3 Cx>R2ChX> RCH2X Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 6 6.16A Dehydrohalogenation (脱卤化氢 ) RCH2CH2 X KOH, EtOH RCH CH2 RCH2CH X X KOH, EtOH RC CH Reactivity： R3CX > R2CHX > RCH2X

ORGANIC CHEMISTRY Chapter 6 CH3 CH2-CH-CH3 KOH, EtOH CH2CH=CHCH Br 81% CH3 CH2CH=CH 19 CH 3 CH3CH2C—CH2KOH,EtOH CH3CH=C(CH3)2 △ Br 71% CH3CH2C=CH2 CH329 Zaitsev(saytzeff) rule: base-induced elimination reactions generally give the more highly substituted alkene product Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 6 CH Br CH3CH2 CH3 KOH, EtOHCH3CH CHCH3 CH3CH2CH CH2 81% 19% C Br CH3CH2 CH3 KOH, EtOHCH3CH C(CH3)2 CH3CH2C CH2 71% 29% CH3 CH3 + + Zaitsev (Saytzeff) rule: base-induced elimination reactions generally give the more highly substituted alkene product

ORGANIC CHEMISTRY Chapter 6 KOH Etoh CH2-CHCH2 CHCH(CH3)- △ Br CH2=CH-CH=CHCH(CH3)2 Conjugated diene 夕+ Belimination C 1.2-elimination Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 6 CH2 CHCH2CHCH(CH3)2 Br KOH, EtOH CH2 CH CH CHCH(CH3)2 Conjugated diene C C X Hβ α 2 1 β elimination 1,2-elimination