Synthesis of ruthenium (II) complexes containing a dihydroperimidine-derived phosphine ligand and their application in transfer hydrogenation of ketones

The new ruthenium (II) phosphine complexes (η6-C6H6)RuCl2[μ- (PPh2CH2N)2CH2(C10H6)]RuCl2(η6-C6H6) (1) and RuCl2(PPh3)[(PPh2CH2N)2CH2(C10H6)] (2) were synthesized and characterized by 1H NMR, 31P {1H} NMR and elemental analysis. Moreover, the structure of ruthenium (II) phosphine complex 1 was confirmed by X-ray crystallography. With complex 1 as the catalyst, the transfer hydrogenation of ketones reacted well, affording the corresponding alcohols in good yields under mild conditions.