药学课件一07卤代烃陆

δ

δ 标

CCH2

CH3CH CH2=CHCH饱和卤代烃

n-butyl

isobutyl

氯chloro溴bromo碘

））卤代烷可极化性次序为：RIRBrRCl一、++

X

+

2 + RNH2+

OH-RNH3

X

CH3CHCH3+NaI

I

+ +AgNO3

RONO2 AgX。3

＞2

＞1

(Elimination

CH2=CH2+HXCH32CH32

H

3 3

RX+ RXOORXOORMgX

R-H+

2RMgX+ 2RX+RMgRH+ +CH3CCMgBr+RMgX+ RX+2RLi+

RLi+R2CuLi+BrBr+(CH3)2CuLidiethyl

CHCHCHCHCH

+ +80%twoandinvertion

SN1

CHCl+

CHOH+ [CH3Cl1234

*I-+ H

H

+ .. CLCLNu

CC BrNaOH CCSN

(R2(R2D =-(S2D =-α= α=A α= α=A

α=-α=α=-α=

Br+

OH+Br-V=

CBr

+

+OH-

ER3C-

+ R3C-

C

R

C+

CH3

3

H

Br

当C+不是足够稳定时，由于L的 Nu:从L背后进攻中心碳原子的机会增大，故构请思考：H

SN

3CH3

3

CH3Br

+

33。

。2

3

C

+-SR

CH2CH2CH3+CH3OH H

(_)

H

++

H

H+H RBr+ I+ 1~3 H X H

R

SSN1反应速率增大,反应~10~10 R

RC

碳正离子稳定性：(CH3)3C>(CH3)2CH>CH3CH2>3oRX>2oRX>1oRX>SN2相对VS N

Br I

HFHClHBrF->Cl-Br- 因为：PhSO2OH是强酸O O

磺

OSOOSO

C2H5O- CH3-OSO2O C2H5OCH CH

R-X 碱性 CH3O―>HO―CH3O―>HO―>PhO―>CH3COO―>NO―>碳负离子胺负离子

D当亲核试剂中取代基的空间效应较大时，则不利于

> >3

>C2H5NH2>(C2H5)2NH>不利于SN2有利于SN2“露”有利于SN1 RX+

+ ++- 2醇水=2醇水=1 CH3CH2OH+ CH3CH2I+OH-2CH3CH2NH2+ CH3CH2Br+NH-2

+ CH3CH2Cl+-CH3O-+ CH3OCH2CH3+(CH3)3CBr+ (CH3)3COH+H X

XCCXH XX-

-

X

H

Hb

C2H5O-

主 主

H

H

HH

HHH

H

C2H5O-

step

C++Cl-step

H C

H

+ Cb +ROH+CbX-X

+(CH)3O(CH)3O+C+CH3 H33HH+(b

CH3CH2ONa+

CH3CH2OCH2CH3+CH2=CH2 CHCHONa+CH

CH

+CH3CH2ONa+

+

难易

易难

)

CH3OH,CH3OH,CH(CH CH3(CH2)16CH

2 2

,H

Nu:-

HB:- X

H Xa +I b(CH3)3CBr+CN- cCH3CHBrCH3+OH- d(CH3)3CBr+ CH3CH CH2=CH- C－Cl键