Heteroleptic Ruthenium(II) Complexes of 2-(2 a Study of Catalytic Efficiency Towards Transfer Hydrogenation of Acetophenone

Abstract

Six ruthenium(II) complexes ([RuCl<inf>2</inf>(p-cymene)(L1-6)], SD1-6, (L1-6: bidentate pyridyl-benzimidazole ligands)) were synthesized from [RuCl<inf>2</inf>(p-cymene)]<inf>2</inf> dimer and bidentate pyridyl-benzimidazole ligands. The compounds were characterized by elemental analysis, IR, UV-Vis, NMR and X-ray diffraction. The synthesized Ru(II) complexes (SD1-6) were tested as catalysts for the catalytic transfer hydrogenation (CTH) of acetophenone to secondary alcohols in the presence of KOH using 2-propanol as a hydrogen source at 82 °C. All complexes were active catalysts for TH of acetophenone with good yields under mild conditions (after 15 min, yields of up to 91%). © 2014 Elsevier Ltd. All rights reserved.