Transfer hydrogenation of acetophenone promoted by (arene)ruthenium(II) reduced Schiff base complexes: an X-ray structure of [(η 6- p-cymene)RuCl(OC 6H 4-2-CH 2NHC 6H 4- p-Me)

Abstract

Arene ruthenium(II) reduced Schiff base complexes of formulation [(η 6- p-cymene)RuCl(L n )] ( 1– 5, n=1–5) were prepared by reacting [(η 6- p-cymene)RuCl 2] 2 with HL n in the presence of sodium carbonate in CH 2Cl 2. The complexes contain an η 6- p-cymene group, a chloride and a bidentate chelating N,O-donor ligand. The molecular structure of [(η 6- p-cymene)RuCl(OC 6H 4-2-CH 2NHC 6H 4- p-Me)] ( 1) has been determined by X-ray crystallography. The complexes are found to be catalytically active for transfer hydrogenation of acetophenone to (±)1-phenylethanol in the presence of KOH and isopropanol showing percent conversion of 98 with the catalysts having a bulky substituent adjacent to the O- and N-donor sites of the auxiliary ligand.