The Regioselective 1,4-Addition Reaction of Alkenylboronic Acids to<i>α</i>,<i>β</i>,<i>α</i>′,<i>β</i>′-Unsaturated Ketones
作者:Shoji Hara、Hisashi Shudoh、Shigeyuki Ishimura、Akira Suzuki
DOI:10.1246/bcsj.71.2403
日期:1998.10
unsymmetric α,β,α′,β′-unsaturated ketones (10a—f) were designed for the regioselective 1,4-addition reaction with alkenylboronic acids (4a—j). Since they have substituents to disturb the 1,4-addition reaction on only one double bond, the alkenylboronic acids reacted with them from only one side to selectively provide γ,δ,α′,β′-unsaturated ketones (11a—q). Further transformations of the resulting γ,δ,α′,β′-unsaturated
详细研究了取代基对α,β-不饱和酮双键对氰尿酰氟诱导烯基硼酸1,4-加成反应速率的影响。当不饱和酮的β-碳周围的位阻增加时,1,4-加成反应速率显着降低。还发现α-碳上的烷基取代基显着影响1,4-加成反应。根据这些结果,不对称的 α,β,α',β'-不饱和酮 (10a-f) 被设计用于与烯基硼酸 (4a-j) 的区域选择性 1,4-加成反应。由于它们具有仅在一个双键上干扰 1,4-加成反应的取代基,因此烯基硼酸仅从一侧与它们反应以选择性地提供 γ,δ,α',β'-不饱和酮 (11a-q)。所得γ、δ、α'的进一步变换,