Cooperative Molybdenum-Thiolate Reactivity for Transfer Hydrogenation of Nitriles

A half-sandwich molybdenum(II) thiolate complex with a eta(2)-MeCN ligand, Cp*Mo(1,2-Ph2PC6H4S)(eta(2)-NCMe) (1(eta(2)-NCMe)), was found to catalyze transfer hydrogenation of nitriles efficiently with ammonia borane (H3N center dot BH3) at room temperature, producing primary amines. Through molybdenum-thiolate cooperation, the B-H bond of. BH3 is cleaved, affording a Mo(II)-H hydride (1H(BH2)) with the BH2 moiety captured at the S-Mo unit. In the presence of NH3, 1H(BH2) smoothly achieves the catalytic transfer hydrogenation of nitriles.