Intramolecular Substitution Reaction of Lithium Alkylidene Carbenoids. Regioselective Synthesis of Indenes
作者:Hideyuki Yanagisawa、Kasei Miura、Mitsuru Kitamura、Koichi Narasaka、Kaori Ando
DOI:10.1246/bcsj.76.2009
日期:2003.10
intramolecular substitution reaction with alkoxide moiety occurs at the lithium alkylidene carbenoid center to give dihydrofurans. The reaction mechanism of this intramolecular substitution reaction is studied by B3LYP density functional calculations with the 6-31+G(d) basis set, and the substitution is found to proceed in a concerted manner. This substitution reaction is applied to the regioselective preparation
当 4,4-dibromo-3-alkenols 用丁基锂处理时,在锂亚烷基卡宾中心发生与醇盐部分的分子内取代反应,得到二氢呋喃。用6-31+G(d)基组通过B3LYP密度泛函计算研究了这种分子内取代反应的反应机理,发现取代以协同方式进行。该取代反应适用于茚衍生物的区域选择性制备。也就是说,用丁基锂处理 3-(o-溴苯基)-1,1-二溴丙烯衍生物 23 会导致形成分子内取代中间体,3-茚基锂 D,其被亲电试剂捕获以区域选择性地提供取代的茚。