Catalyst Repurposing Sequential Catalysis by Harnessing Regenerated Prolinamide Organocatalysts as Transfer Hydrogenation Ligands
作者:Frederic Bourgeois、Jonathan A. Medlock、Werner Bonrath、Christof Sparr
DOI:10.1021/acs.orglett.9b04033
日期:2020.1.3
A catalyst repurposing strategy based on a sequential aldol addition and transfer hydrogenation giving access to enantiomerically enriched α-hydroxy-γ-butyrolactones is described. The combination of a stereoselective, organocatalytic step, followed by an efficient catalytic aldehyde reduction induces an ensuing lactonization to provide enantioenriched butyrolactones from readily available starting
描述了基于顺序的醛醇加成和转移氢化的催化剂再利用策略,该策略允许获得对映异构体富集的α-羟基-γ-丁内酯。立体选择性的有机催化步骤的组合,然后是有效的催化醛还原,引起随后的内酯化,以从容易获得的起始原料中提供对映体富集的丁内酯。通过利用脯氨酸酰胺既充当有机催化剂又充当转移加氢配体的能力,催化剂的再利用允许开发一种操作简单,经济且有效的顺序催化方法。