Chemoselective hydrogenation of nitriles to secondary or tertiary amines catalyzed by aqueous-phase catalysts supported on hexagonal mesoporous silica

The first supported aqueous-phase catalyst for the hydrogenation of nitriles is revealed. The catalyst prepared from Pd(PhCN)(2)Cl-2, water-soluble ligand 2,2 '-biquinoline-4,4 '-dicarboxylic acid dipotassium salt and mesoporous silica is a highly efficient catalyst for the selective formation of secondary or tertiary amines from aromatic or aliphatic nitriles. The catalytic system is stable and can be recycled and reused three times without loss of activity and selectivity. This environmentally friendly process is, in addition, an attractive alternative to many homogeneous and heterogeneous catalysts because of its easy preparation and the moderate operational conditions under which it is highly active.