Unusual Carbon−Carbon Bond Formations between Allylboronates and Acetals or Ketals Catalyzed by a Peculiar Indium(I) Lewis Acid
作者:Uwe Schneider、Hai T. Dao、Shu̅ Kobayashi
DOI:10.1021/ol100450s
日期:2010.6.4
mechanism is proposed in which a single InI center acts as a dual catalyst to activate both reagents sequentially. Contrary to the classic γ-selectivity of allylsilanes (Hosomi−Sakuraireaction), this InI-catalyzed boronovariant displays distinct α-selectivity. Substrate scope and functional group tolerance proved to be excellent.
在I OTf中,已发现它是有效的路易斯酸催化剂,用于用烯丙基硼酸酯对乙缩醛或缩酮进行前所未有的亲核取代。提出了一种超金属化S N 1机制,其中单个In I中心充当双重催化剂,以依次激活两种试剂。与烯丙基硅烷的经典γ选择性(Hosomi-Sakurai反应)相反,此In I催化的硼烷变体表现出独特的α选择性。底物范围和官能团耐受性被证明是极好的。