Manganese catalyzed enantio- and regioselective hydrogenation of α, β-unsaturated ketones using an imidazole-based chiral PNN tridentate ligand

The enantioselective 1,2-reduction of alpha,beta-unsaturated ketones has been achieved using a chiral pincer Mn catalyst. A series of PNN tridentate ligands containing benzimidazole groups were designed with ferrocene as the backbone, which coordinated with Mn to form the active catalyst. This mild process represents a general method to access chiral allyl alcohols with high catalytic activity (up to 9500 TON) and high enantioselectivity (66-86% ee). Furthermore, this catalytic system provides a novel synthesis of key pharmaceutical intermediates of cannabidiol. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study demonstrates an enantioselective 1,2-reduction of alpha,beta-unsaturated ketones using a chiral pincer Mn catalyst, leading to the synthesis of chiral allyl alcohols with high catalytic activity and enantioselectivity. The process also provides a novel synthesis route for key pharmaceutical intermediates of cannabidiol.