Synthesis, Characterization and Catalytic Properties of New Diamino/Diphosphine Ruthenium Complexes

Polydentate ligands, N, N'-bis[o-(diphenylphosphino)benzylidene]-1,2-propane-diamine [P2N2Me for short] and N, N'-bis[o-(diphenylphosphino)benzyl]-1,2-propanediamine [P2N2H4Me for short] have been synthesized. The interaction of RuCl2(DMSO)(4) with one equivalent of P2N2Me or P2N2H4Me in refluxing toluene gave trans-RuCl2(P2N2Me) and trans-RuCl2(P2N2H4Me) in good yield, respectively. The ligands and the complexes have been fully characterized by elemental analysis and spectroscopic methods. The complexes act as an excellent catalyst precursor in hydrogen transfer hydrogenation of acetophenone in catalyst : acetophenone : iso-PrOK of 1 : 100 : 15, leading to 2-phenylethanol of 89 similar to 96% yield.