PS-Pd-NHC: an efficient and heterogeneous recyclable catalyst for direct reductive amination of carbonyl compounds with primary/secondary amines in aqueous medium

A highly efficient polymer supported palladium-N-heterocyclic carbene (PS-Pd-NHC) catalytic system has been developed for direct reductive amination (DRA) of carbonyl compounds with primary/secondary amines in aqueous reaction medium. This new catalytic system represents a heterogeneous, recyclable and environmentally benign protocol. The developed methodology describes a simple one step approach for the synthesis of a wide variety of substituted amines exhibiting remarkable activity with excellent yield of a desired product. Furthermore, the catalyst was effectively recycled for six consecutive cycles without any significant loss in its catalytic activity.