Catalytic hydrogenation of ethyl 2-amino-2-difluoromethyl-4-cyanobutanoate and its Schiff base reaction modes

Under heterogeneous catalysis, ethyl 2-amino-2-difluoromethyl-4-cyanobutanoate or its Schiff base could be selectively reduced in good yield by hydrogenation to give a diamine, or to form a five-membered ring or a six-membered ring heterocycles. This selectivity is highly dependent on the type of catalysts used.