Development of New Hydrogenations of Imines and Benign Reductive Hydroaminations: Zinc Triflate as a Catalyst

The hydrogenation of imines to amines in the presence of catalytic amounts of zinc triflate has been demonstrated for the first time. In addition, an efficient procedure for the reductive hydroamination of alkynes to amines is presented using zinc triflate as a catalyst precursor. In both protocols a variety of different functional groups are tolerated, and the reactions proceed smoothly in high yields. It's a triflate with zinc: The hydrogenation of imines and the reductive hydro‐ amination of alkynes with hydrogen and amines have been achieved by applying zinc triflate as a catalyst. This methodology is a convenient alternative to the use of precious metal‐based catalysts and expensive silanes and Hantzsch ester dihydropyridines.