Homogeneous Hydrogenation and Hydroformylation using Ruthenium Complexes

WE have shown1 that the rhodium (I) complex, RhCl(PPh3)3, is an extremely efficient catalyst for the homogeneous hydrogenation of olefines and acetylenes at 25° C and at < 1 atmosphere pressure in benzene solutions. This activity is due, in part, to the dissociation of the complex in solution to give a solvated species RhCl(PPh3)2S, which has a vacant co-ordination site additional to the solvent-occupied axial positions.