Cobalt-Catalyzed Synthesis of Unsymmetrically N, N-Disubstituted Formamides via Reductive Coupling of Primary Amines and Aldehydes with CO 2 and H 2 .

Herein, a novel route to synthesize unsymmetrically N, N-disubstituted formamides is reported, which is achieved via reductive coupling of primary amine and aldehyde with CO ₂ /H ₂ over a cobalt-based catalytic system composed of CoF ₂ , P(CH ₂ CH ₂ PPh ₂ ) ₃ and K ₂ CO ₃ . The mechanism investigation indicates that a secondary amine is formed via hydrogenation of the imine originated from aldehyde and primary amine, which further reacts with HCOOH generated from CO ₂ hydrogenation, resulting in the formation of NNFA finally.