亲核性1,2-重排为何迁移基团的构型保持不变

Why Do the Chiral Shift Groups Keep Their Configuration in the Nucleophilic 1,2-Rearrangements

亲核性1,2-重排反应是有机化学的重要反应之一,重排中离去基团的离去和迁移基团的迁移步骤既可以是分步的,也可以是协同的,但是迁移基团的构型始终保持不变。本文用超共轭效应和反应过程中有机立体电子效应解释了此现象,掌握一般规律,希望能够从教学上便于教师讲授和学生学习理解。

Nucleophilic 1,2-rearrangements are one class of important organic reactions.Leaving of the leaving groups and shift of the shift groups can be either stepwise or concerted.However,the rearrangements always occur with retention of the configuration at the migrating carbon of the shift groups.This article introduces using hyperconjugation and stereoelectronic effect to explain the phenomenon and to grasp the general rule,hoping to provide help for teachers’teaching and students’understanding in teaching and learning organic chemistry.