大学化学 >> 2025, Vol. 40 >> Issue (12): 187-191.doi: 10.12461/PKU.DXHX202510104

师生笔谈 上一篇    下一篇

经典Hofmann消除反应的机理探究

程宏宇1, 王瑞瑶2, 孙兴文1   

  1. 1 复旦大学化学系, 上海 200433;
    2 复旦大学附属中学, 上海 200433
  • 收稿日期:2025-10-29 录用日期:2025-12-03 发布日期:2025-12-27
  • 通讯作者: 孙兴文 E-mail:sunxingwen@fudan.edu.cn Xingwen Sun
  • 基金资助:
    校级重点教研项目(2023xjyxm004,2023xjyxm012,2024xjyxm032);省级虚拟教研室项目(2023xnjys001)

Mechanistic Study of the Classic Hofmann Elimination Reaction

Hongyu Cheng1, Ruiyao Wang2, Xingwen Sun1   

  1. 1 Department of Chemistry, Fudan University, Shanghai 200433, China;
    2 High School Affiliated to Fudan University, Shanghai 200433, China
  • Received:2025-10-29 Accepted:2025-12-03 Published:2025-12-27
  • Contact: Xingwen Sun E-mail:sunxingwen@fudan.edu.cn

摘要: 对本科教学中涉及的开链季铵碱和环状季铵碱的消除机理进行了分析;对于环状季铵碱,当有两种反式共平面的β-H时,倾向于消除取代基较多的碳上的氢,得到扎伊采夫取向的烯烃为主要的产物,该结论也通过计算化学的手段得到佐证。该论文对Hofmann消除的本科教学是个丰富和支撑。

关键词: 季铵碱, 霍夫曼消除, 扎伊采夫取向, 霍夫曼取向

Abstract: This paper evaluates the mechanisms of the classic Hofmann elimination, especially the elimination reaction of cyclic quaternary ammonium hydroxide. When there are two trans-coplanar β-H, the hydrogen on the carbon with more substituents tends to be eliminated, resulting in the main product being an olefin with Zaitsev selectivity. This conclusion is also supported by DFT study result.

Key words: Quaternary ammonium hydroxide, Hofmann elimination, Zaitsev selectivity, Hofmann selectivity