Double Asymmetric Hydrogenation of Linear β,β-Disubstituted α,β-Unsaturated Ketones into γ-Substituted Secondary Alcohols using a Dual Catalytic System
作者:Noriyoshi Arai、Hironori Satoh、Ryo Komatsu、Takeshi Ohkuma
DOI:10.1002/chem.201701527
日期:2017.7.3
β‐unsaturated ketones catalyzed by the DM‐SEGPHOS/DMAPEN/RuII complex with t‐C4H9OK afforded the γ‐substituted secondary alcohols in high diastereo‐ and enantioselectivities. Some mechanistic experiments suggested that two different reactive species, type (I) and (II), were reversibly formed in this catalytic system: Type (I) with the diamine ligand DMAPEN enantioselectively hydrogenated the enones
的线性β,β-二取代的α,β不饱和酮由DM-SEGPHOS / DMAPEN /钌催化的双不对称氢化II络合物吨-C 4 ħ 9OK提供了高非对映体和对映体选择性的γ-取代仲醇。一些机理实验表明,在该催化体系中可逆地形成了两种不同的反应物种,即类型(I)和(II):类型(I)与二胺配体DMAPEN对映体将烯酮对映体选择性地氢化成手性烯丙基醇,类型(II) )没有二胺配体的非对映选择性地将烯丙醇氢化为γ-取代的仲醇。这种双重催化方案已成功应用于各种脂族和芳族取代的烯酮底物的反应。