作者:Xavier Creary、Mark A. Butchko
DOI:10.1021/jo001112b
日期:2001.2.1
derived from trimethylsilyl migration. These reactions were interpreted in terms of rapid trimethylsilyl migration to carbene-like centers that compete effectively with ring expansion processes of cyclopropylcarbenes. Computational studies (B3LYP/6-31G) suggest that cyclopropyl stabilization of carbenes is more effective than beta-trimethylsilyl stabilization. However, beta-trimethylsilyl stabilized conformations
环丙基三甲基甲硅烷基甲基酮的甲苯磺酰derivative衍生物的原位生成的锂盐的热分解产生1-环丙基-1-三甲基甲硅烷基乙烯,这是甲硅烷基专有的迁移产物。1-三甲基甲硅烷基环丙基烷基酮的甲苯磺酰derivatives衍生物的钠盐的热分解也得到了衍生自三甲基甲硅烷基迁移的亚甲基环丙烷产物。这些反应是根据三甲基甲硅烷基快速迁移到卡宾样中心来解释的,这些中心可与环丙基卡宾的扩环过程有效竞争。计算研究(B3LYP / 6-31G)表明,卡宾的环丙基稳定作用比β-三甲基甲硅烷基稳定作用更有效。但是,很容易获得β-三甲基甲硅烷基稳定的构象,这些构象可能导致甲硅烷基迁移。甲基-1-三甲基甲硅烷基环丙基卡宾有两个最小能量构象,27,这些构象相互转化的旋转势垒(5.4 kcal / mol)大大低于母体环丙基卡宾(15 kcal / mol)。提出了在卡宾空轨道与相邻的Si-C sigma-轨道之间的过渡态