Preparation of Thiolate-Bridged Dinuclear Ruthenium Complexes Bearing a Phosphine Ligand and Application to Propargylic Reduction of Propargylic Alcohols with 2-Propanol

Novel thiolate-bridged dinuclear ruthenium complexes bearing a phosphine ligand, [Cp*Ru{PhP(C6H4-o-S)2}RuCp*](OTf)2, [CpRu{PhP(C6H4-o-S)2}RuCp*(OH2)](OTf)2, and [Cp*Fe{PhP(C6H4-o-S)2}RuCp*](OTf)2, are prepared and characterized by X-ray analysis. These dinuclear complexes work as effective catalysts toward propargylic reduction of propargylic alcohols with 2-propanol via allenylidene complexes as key intermediates to give the corresponding alkynes in good to high yields.