Highly Regioselective Allylation of α-Enones and Epoxides with Lithium Tetraallyllanthanoid Ate Complex
作者:Shin-ichi Fukuzawa、Shizuyoshi Sakai
DOI:10.1246/bcsj.65.3308
日期:1992.12
be involved in this carbonyl allylation reaction with 1. Allylative ring opening of styrene oxide with 1 occurs at the more subsituted carbon (α-attack) in higher selectivity (α : β = 85 : 15) than with allyllithium and allylmagnesium bromide in diethyl ether. The complex 1 reacts with 3,4-epoxy-1-butene (35) in diethyl ether predominantly at the most substituted carbon of the oxirane to give 3-hydroxymethyl-1
由四烯丙基锡、三氯化镧和丁基锂在四氢呋喃 (THF) 中很容易原位制备的四烯丙基镧系化合物 (1) 与 α-烯酮 (3-11) 以高度的 1,2-区域选择性 (1) 顺利反应,2 : 1,4 = >99 : 1) 以良好到极好的产率得到 1,5-二烯-3-醇。以 4,4-(乙二氧基)-2,6-二甲基-2,5-环己二烯酮 (29) 作为探针的机理研究表明,单电子转移 (SET) 可能参与了与 1. 烯丙基化环的羰基烯丙基化反应与烯丙基锂和烯丙基溴化镁在乙醚中相比,氧化苯乙烯与 1 的开环发生在更多取代的碳(α-攻击)上,选择性更高(α : β = 85 : 15)。络合物 1 与 3 反应,