Mild and Homogeneous Cobalt‐Catalyzed Hydrogenation of CC, CO, and CN Bonds

A cationic cobalt(II)–alkyl complex is an effective precatalyst for hydrogenation of alkenes, aldehydes, ketones, and imines under mild conditions (1–4 atm H2; see scheme). The catalyst shows a high functional-group tolerance across a broad range of substrates. Experiments suggest that the active catalytic species is a cobalt(II)–hydride complex.