Asymmetric hydrogenation by ruthenium cluster hydrides containing atropoisomeric diphosphine ligands

Ruthenium clusters containing atropoisomeric diphosphines, namely [Ru4(μ-H)4(CO)10{(S)-(-)-BINAP}], where Bl-NAP is 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl and [Ru4(μ-H)4(CO)10{(S)-(-)-MOBIPH}], where MOBIPH is 2,2′-bis(diphenylphosphino)-6,6′-dimethoxy-1,1′-diphenyl, have been used as catalysts in the asymmetric hydrogenation of some prochiral substrates containing C=C or C=O double bonds. With the BINAP derivative optical purities up to 30% were achieved.