Expedient Cobalt-Catalyzed C–H Alkynylation of (Enantiopure) Benzylamines

Abstract

A unified strategy for cobalt-catalyzed ortho-C-H bond alkynylation of benzylamines is reported. Simple, commercially available CoBr₂ was used as a cobalt source. The developed alkynylation strategy is robust and efficient and has a broad substrate scope including 1°, 2°, and 3° benzylamines. The mechanistic study shows that C-H bond cleavage is reversible, and the kinetic study illustrates that the rate of reaction depends solely on the catalyst.