Iridium-Catalyzed Asymmetric Hydrogenation of Unfunctionalized, Trialkyl-Substituted Olefins
作者:Aie Wang、Rui P. A. Fraga、Esther Hörmann、Andreas Pfaltz
DOI:10.1002/asia.201000595
日期:2011.2.1
Chiral iridium complexes with bicyclic pyridine‐based N,P ligands have emerged as efficient catalysts for the enantioselective hydrogenation of unfunctionalized trialkyl‐substituted olefins. Optimization of the reaction conditions by variation of the solvent, pressure, and temperature led to enantiomeric excesses of up to 99 %. Three pure alkenes, (E)‐2‐cyclohexyl‐2‐butene and (E)‐ and (Z)‐3,4‐dimethyl‐2‐pentene
具有双环吡啶基N,P配体的手性铱配合物已成为未官能化三烷基取代烯烃对映选择性加氢的有效催化剂。通过改变溶剂,压力和温度来优化反应条件,导致对映体过量高达99%。将(E)-2-环己基-2-丁烯和(E)-和(Z)-3,4-二甲基-2-戊烯这三种纯烯烃分别转化为相应的手性烷烃,分别为97%,94%和93 % ee, 分别。醋酸α-和γ-生育三烯基酯的三个C bondsC键的加氢导致醋酸α-和γ-生育酚酯具有非常高的非对映选择性。相同的催化剂已成功用于加氢取代带有γ位羧酸酯或酮基的三取代烯烃。该反应被用作关门菌西双螺旋菌的信息素的高度对映选择性合成中的关键步骤。结构类似的烯丙基醇的氢化也给出了高对映选择性。