亲电反应中的缺电子中心

Electron-Deficient Centres in Electrophilic Reaction

对于不饱和烃类化合物的亲电反应,在反应类型上,有亲电加成和亲电取代;在反应产物上,有取代产物和加成产物,而且在加成产物中既有马氏加成、又有反马氏加成产物。知识点多而且复杂,学生学习记忆往往比较困难。本文以缺电子中心为主线,系统分析了亲电反应中的4种主要缺电子中心(包括正离子、自由基、卡宾和中性分子),从其结构特点和反应机理归纳总结了各种反应底物的亲电反应,以期对亲电反应有一个更深入、系统的认识。

Electrophilic reactions of unsaturated hydrocarbons have two categories,electrophilic addition and electrophilic substitution; thus the reaction products are addition products and substitution products. As for the addition products,there are Markovnikov products and anti-Markovnikov products. These complicated knowledge will increase learning difficulties for college students. In this paper,taking electron-deficient centres as the main line,four main electronic-deficient centers including positive ions, free radicals, carbene and neutral molecules in electrophilic reaction were systematically analyzed,and the electrophilic reactions of various substrates were also summarized from reaction mechanism and structural characteristics of various electron-deficient centres. And with this,students can have a more in-depth and systematic understanding to electrophilic reaction.