the presence of HMPA at −45°C afforded silylallyllithium 2a bearing an oxide anion on the silicon atom. The reaction of 2a with various electrophiles gave γ-products selectively in good yields. Higher regio- and stereoselectivities were achieved in the reaction of silyl-substituted allyllithium derived from potassium allylsilanolate with butyllithium.
在-45℃下在HMPA存在下用两个当量的丁基
锂处理烯丙基二苯基
硅烷醇(1),得到在
硅原子上带有氧化阴离子的甲
硅烷基烯
丙基锂2a。2a与各种亲电试剂的反应以高收率选择性地产生γ-产物。在衍生自烯丙基
硅烷醇
钾的甲
硅烷基取代的烯
丙基锂与丁基
锂的反应中,实现了更高的区域选择性和立体选择性。