DIHYDROGEN REDUCTION OF ORGANIC SUBSTRATES USING ORTHOMETALLATED RUTHENIUM (II) COMPLEX CATALYSTS

Dihydrogen reduction of aliphatic and aromatic nitrocompounds and nitr iles, aliphatic ketones and Schiff bases to their corresponding satura ted products was efficiently carried out in presence of dinuclear orth ometallated ruthenium (II) complexes of the type [RuL(CO)2Cl]2 (LH = 2 -phenylpyridine, benzo (h) -quinoline, 1 -phenylpyrazole and azobenzen e) as catalyst precursors under high pressure, high temperature condit ions in either DMF or DMSO medium. The dinuclear complexes undergo dis sociation to the corresponding monomer solvent adducts, [RuL(CO)2Cl.S] (S = DMF, DMSO) which are suggested to be the actual catalytic specie s. The probable mechanism for the reduction has been suggested on the basis of kinetic studies and physico-chemical properties of the cataly st solution during high pressure run.