Reductive Amination of Carbonyl Compounds over Silica Supported Palladium Exchanged Molybdophosphoric Acid Catalysts

Palladium exchanged molybdophosphoric acid supported on silica is reported as a highly effective catalyst for direct reductive amination of carbonyl compounds. The catalysts are characterized by X-ray diffraction and FT-infrared spectroscopy. The characterization results support the existence of Keggin ion of heteropoly molybdate on silica. The catalyst is facile, water tolerable and environmentally benign for reductive amination. A variety of secondary and tertiary amines can be synthesized over this catalyst in excellent yields under mild reaction conditions. A plausible reaction mechanism is proposed for the reductive amination of carbonyl compounds over this catalyst. An efficient heterogeneous silica supported palladium exchanged molybdophosphoric acid catalyst is demonstrated for the synthesis of different reductive amination products by reaction of carbonyl compounds with amines under mild reaction conditions. The catalyst exhibited high selectivity with excellent yield with in short reaction time.