我们报告了一种远程官能化策略,该策略允许通过 Ni 催化的链从远处的烯烃位点步行来Z选择性合成(杂)芳族和脂肪族酮的甲硅烷基烯醇醚。位置选择性由链游走的方向性控制,并且与所得甲硅烷基烯醇醚的热力学偏好无关。我们的机理数据表明,在这些条件下形成Ni (I)二聚体,作为催化剂静止状态,并在与烷基溴反应后转化为 [Ni (II) -H] 作为活性链行走/功能化催化剂,最终生成稳定的 η 3 键合Ni (II) 烯醇作为关键的选择性控制中间体。
Stereochemical Investigations of Samarium(II) Iodide-Promoted 5-Exo and 6-Exo Ketyl-Olefin Radical Cyclization Reactions
作者:Gary A. Molander、Jeffrey A. McKie
DOI:10.1021/jo00109a018
日期:1995.2
Samarium(II) iodide (SmI2)-promoted ketyl cyclizations of several substituted, unsaturated ketones, providing various cyclopentyl and cyclohexyl systems, have been investigated. The resulting experiments provide stereochemical insight into these reactions and in addition outline the synthetic potential of these 5-exe and 6-exo radical cyclization processes.