高等学校化学学报

高等学校化学学报 ›› 1998, Vol. 19 ›› Issue (5): 723.

• 论文 • 上一篇    下一篇

氯代卡宾与羰基化合物反应的研究——取代基的电子效应和底物的芳构化对脱氧反应的影响

王洪星1, 程津培1, 谷文祥2, 张高举1, 还振威1, 鲁云1   

  1. 1. 南开大学化学系, 天津, 300071;
    2. 华南农业大学生态所, 广州, 510642
  • 收稿日期:1997-06-12 出版日期:1998-05-24 发布日期:1998-05-24
  • 通讯作者: 程津培
  • 作者简介:王洪星,男,33岁,讲师.
  • 基金资助:

    国家自然科学基金

Reactions of Fluorocarbenes with Carbonyl Compounds ——The Effects of para-Substituents and Pre aromatic Character on Deoxygenation of Aryl Aldehydes and Tetraphenyl-cyclopentadienone

WANG Hong-Xing1, CHENG Jin-Pei1, GU Wen-Xiang2, ZHANG Gao-Ju1, HUAN Zhen-Wei1, LU Yun1   

  1. 1. Department of Chemistry, Nankai University, Tianjin, 300071;
    2. Institute of Ecology, South China University of Agriculture, Guangzhou, 510642
  • Received:1997-06-12 Online:1998-05-24 Published:1998-05-24

PDF (PC)

摘要： 氯溴卡宾与系列取代苯甲醛作用均产生CO(即羰基脱氧产物),取代基的电子效应直接影响CO的产率.捕获反应证实,该反应经历0°,0°型羰基叶立德中间体阶段.氟氯(溴)卡宾与四苯基环戊二烯酮(TPCP)反应除得到高产率的CO外,还生成偕氟卤环戊二烯(8)、双键加成物(9)及其重排产物(10).该类反应以脱CO途径为主,这可能是由于中间体羰基叶立德内部存在着"推-拉"稳定效应和不利于分子内电环化和分子间1,3-偶极加成的0°,90°型构象.本文讨论了这两类反应的微观作用机制.

关键词: 氯代卡宾, 羰基叶立德, 脱氧反应

Abstract: The reactions of :CFBr with substituted benzaldehydes resulted in deoxygenation products with varying yields of COproduction which appeared to associate with the electronic effects of the para-substituents. The proposal that this type of carbene reactions proceed via formation of a carbonyl Ylide intermediate was confirmed by a successful trapping experiment using a planar Ylide trapper, dimethylacetylenedicarboxylate(DMAD). On the other hand, no carbonyl Ylide was trapped in a similar reaction of fluorocarbenes(:CFBr or :CFCl) with sterically hindered tetraphenylcyclopentadienone(TPCP). This observation, together with the fact of an unexpected high yield of COemission, suggests that the carbonyl Ylide intermediate must have taken a geometry that is far from the so-called 0°, 0° conformation(planar) and therefore largely blocked the involvement of other competitive pathways.

Key words: Chloro-substituted Ylide, Carbony Ylide, Deoxogenation

中图分类号: 

TrendMD: