Catalytic transfer hydrogenation of ketones catalyzed by orthometalated ruthenium(III) 2-(arylazo)phenolate complexes containing triphenylarsine

Air-stable, mononuclear orthometalated ruthenium(III) 2-(arylazo)phenolate complexes of the general composition [RuX(AsPh3)2(L)] (X = Cl or Br; L = CNO donor of the 2-(arylazo)phenolate ligands) have been synthesized and characterized by IR, UV–vis, and EPR as well as by elemental analysis. One of the complexes [RuBr(AsPh3)2(azo–OMe)] was structurally characterized by X-ray analysis and was found to be an efficient catalyst for the transfer hydrogenation of ketones with excellent conversion in the presence of isopropanol at 80 °C in 1 h.