Counterion Enhanced Organocatalysis: A Novel Approach for the Asymmetric Transfer Hydrogenation of Enones
作者:Fabian Scharinger、Ádám Márk Pálvölgyi、Veronika Zeindlhofer、Michael Schnürch、Christian Schröder、Katharina Bica‐Schröder
DOI:10.1002/cctc.202000414
日期:2020.7.21
organocatalytic transfer hydrogenations relying on an ion‐paired catalyst of natural l ‐amino acids as main source of chirality in combination with racemic, atropisomeric phosphoric acids as counteranion. The combination of a chiral cation with a structurally flexible anion resulted in a novel chiral framework for asymmetric transfer hydrogenations with enhanced selectivity through synergistic effects. The optimized
我们提出了一种新的有机催化转移氢化策略,该策略依赖于天然l的离子对催化剂-氨基酸作为手性的主要来源,与作为抗衡阴离子的外消旋、阻转异构磷酸相结合。手性阳离子与结构灵活的阴离子的组合产生了一种新的手性框架,用于不对称转移氢化,通过协同效应提高了选择性。优化的催化体系与 Hantzsch 酯作为仿生转移氢化的氢源相结合,在温和条件下实现了一系列 α,β-不饱和环己烯酮的高对映选择性和优异的产率。此外,由于使用了现成的手性池衍生的构建块,与目前的技术水平相比,它可以以一种直接且便宜得多的方式制备。