Hydrogenation of nitriles to primary amines by a phosphine-free cobalt(II) complex in the absence of H2 gas

We report a well-defined Cobalt(II) complex supported by a tetradentate nitrogen-donor ligand, N,N-bis(pyridin-2-ylmethyl)quinolin-8-amine (BPMQA), which efficiently catalyzes the selective reduction of aromatic, heteroaromatic, aliphatic, and benzylic nitriles to the corresponding primary amines. Notably, the transformation proceeds without the need for external hydrogen gas or pressurized reaction conditions. The use of a non-pincer, phosphine-free ligand framework enables high catalytic efficiency at a low catalyst loading of 0.5 mol%, providing a practical and sustainable approach to nitrile hydrogenation without the requirement of hazardous high pressurized hydrogen gas.