Recent progress in cobalt-catalyzed enantioselective hydrogenation and hydroboration reactions of alkenes

Transition metal-catalyzed asymmetric hydrofunctionalization of alkenes provides straightforward approaches to access optically active organic compounds. Rhodium compounds ligated by chiral phosphine ligands are the most frequently used catalysts for enantioselective hydrogenation reactions of unsaturated organic molecules containing C=C and C=N bonds. However, the rapid development of cobalt catalysis over the past decade shows that some cobalt catalysts have equal or even better catalytic performances compared with their rhodium congeners in asymmetric hydrofunctionalization reactions of alkenes. This review highlights the recent progress in cobalt-catalyzed enantioselective hydrogenation and hydroboration of alkenes, mainly from 2018 to early 2021. Mechanistic considerations of these cobalt-catalyzed reactions will also be discussed.