Cobalt‐Catalyzed Chemo‐ and Enantioselective Hydrogenation of Conjugated Enynes
Yanhua Hu, Zhenfeng Zhang, Yangang Liu, Wanbin Zhang
Abstract
Abstract Asymmetric hydrogenation is one of the most powerful methods for the preparation of single enantiomer compounds. However, the chemo‐ and enantioselective hydrogenation of the relatively inert unsaturated group in substrates possessing multiple unsaturated bonds remains a challenge. We herein report a protocol for the highly chemo‐ and enantioselective hydrogenation of conjugated enynes while keeping the alkynyl bond intact. Mechanism studies indicate that the accompanying Zn 2+ generated from zinc reduction of the Co II complex plays a critical role to initiate a plausible Co I /Co III catalytic cycle. This approach allows for the highly efficient generation of chiral propargylamines (up to 99.9 % ee and 2000 S/C) and further useful chemical transformations.