Impact of fluorine substituents on the rates of nucleophilic aliphatic substitution and β-elimination

被引：43

作者：

Martinez, Henry ^{[1
]}

Rebeyrol, Adele ^{[1
]}

Nelms, Taylor B. ^{[1
]}

Dolbier, William R., Jr. ^{[1
]}

机构：

[1] Univ Florida, Dept Chem, Gainesville, FL 32611 USA

来源：

JOURNAL OF FLUORINE CHEMISTRY | 2012年 / 135卷

关键词：

Nucleophilic aliphatic substitution; beta-Elimination; Williamson synthesis; Effect of fluorine substitution; SN2; REACTIVITY; HALOGEN ATOMS; SOLVENT; MOLECULE; HALIDES; ION;

D O I：

10.1016/j.jfluchem.2011.10.008

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

A measure of the quantitative effect of proximate fluorine substituents on the rates of S(N)2 and E2 reactions has been obtained through a study mainly of reactions of fluorinated n-alkyl bromides with weak base, strong nucleophile azide ion and strong base/nucleophile methoxide on in the protic solvent methanol and the aprotic solvent, DMSO. The order of reactivity for S(N)2 reactions of azide in methanol at 50 degrees C was found to be: n-alkyl-Br > n-alkyl-CHFBr > n-perfluoroalkyl-CH2CH2Br >> n-perfluoroalkyl-CH2Br > n-alkyl-CF2Br. Approximate relative rates of reaction were: 1, 0.20, 0.12, 1 x 10(-4), <7.7 x 10(-5). The order of reactivity for E2 reactions was found to be: n-perfluoroalkyl-CH2CH2Br >> n-alkyl-CF2Br > n-alkyl-CHFBr > n-alkyl-Br. The approximate relative rates for reaction of methoxide in methanol at 50 degrees C were: 1100, 4.4, 1.9, 1. (C) 2011 Elsevier B.V. All rights reserved.

引用

页码：167 / 175

页数：9

共 25 条

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