Wada Reiko, Oisaki Kounosuke, Kanai Motomu, Shibasaki Masakatsu
Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan.
J Am Chem Soc. 2004 Jul 28;126(29):8910-1. doi: 10.1021/ja047200l.
The first example of catalytic enantioselective allylboration and crotylboration of simple ketones is described. High enantioselectivity (up to 93% ee) was obtained using 3 mol % CuF-iPr-DuPHOS as a chiral catalyst and 4.5 mol % La(OiPr)3 as a cocatalyst. Mechanistic studies strongly suggested that the active nucleophile of the present reaction is an allylcopper, and that La(OiPr)3 facilitates the generation of an active allylcopper from the allylboronate, without affecting the transition-state structure of the ketone allylation step.
本文描述了简单酮的催化对映选择性烯丙基硼化和巴豆基硼化的首个实例。使用3 mol%的CuF-iPr-DuPHOS作为手性催化剂和4.5 mol%的La(OiPr)3作为助催化剂,可获得高达93% ee的对映选择性。机理研究有力地表明,本反应的活性亲核试剂是烯丙基铜,并且La(OiPr)3促进了从烯丙基硼酸酯生成活性烯丙基铜,而不影响酮烯丙基化步骤的过渡态结构。