Dihalocarbene Insertion Reactions into C−H Bonds of Compounds Containing Small Rings: Mechanisms and Regio- and Stereoselectivities<sup>,</sup>
作者:Udo H. Brinker、Guoying Lin、Linxiao Xu、William B. Smith、Jean-Luc Mieusset
DOI:10.1021/jo7013356
日期:2007.10.1
products are formed as the major isomers. In some compounds cyclopropane rings “activate” adjacent carbon−hydrogen bonds, whereas other systems containing three-membered rings do not. Moreover, the influence of various substituents (methyl, geminal dimethyl, phenyl, methoxy, and ethoxy) attached to bicyclo[3.1.0]hexane and bicyclo[4.1.0]heptane in dihalocarbene reactions has been studied. The findings
据报道,新型二氯和二溴卡宾插入到邻近环丙烷环的碳氢键中的插入反应。发现与双环[4.1.0]庚烷的反应中形成的主要异构体是由于插入到三元环的碳氢键内。在双环的反应[3.1.0]己烷,然而,外形成了二卤卡宾插入产物作为主要异构体。在某些化合物中,环丙烷环会“激活”相邻的碳氢键,而其他包含三元环的系统则不会。此外,已经研究了在二卤卡宾反应中连接到双环[3.1.0]己烷和双环[4.1.0]庚烷的各种取代基(甲基,双甲基二甲基,苯基,甲氧基和乙氧基)的影响。可以用环丙烷环的沃尔什轨道和α碳氢键的最大轨道重叠概念来解释这一发现。与之形成鲜明对比的是,观察到在双环[4.2.0]辛烷中选择性插入环丁烷环的叔碳氢键中。