Ruthenium-catalyzed transfer hydrogenation of aromatic ketones with aminophosphine or bis(phosphino)amine ligands derived from isopropyl substituted anilines

Abstract

A series of new highly active Ru(II) complexes with two new (N-diphenylphosphino)isopropylanilines, having an isopropyl substituent at carbon 2- (1) or 2,6- (2) and two new bis(diphenylphosphino)isopropylanilines, having an isopropyl substituent at carbon atom 2- (3) or 4- (4), were prepared starting from the dimeric complex [Ru(eta(6)-p-cymene)(mu-Cl)Cl](2). All the compounds have been fully characterized by microanalysis, IR, P-31{1H} NMR, H-1 NMR and C-13 NMR spectroscopies. Following activation by NaOH, complexes 5-8 were tested in the transfer hydrogenation of acetophenone derivatives with iso-PrOH as the hydrogen source. Catalytic studies showed that the complexes are excellent catalytic precursors for the transfer hydrogenation of acetophenone derivatives. (C) 2010 Elsevier Ltd. All rights reserved.