A sulfur mimic of 1,1-bis(diphenylphosphino)methane: a new ligand opens up

Abstract

A simple method for synthesizing diphosphine monosulfide species was developed utilizing lithium sulfide and chlorophosphine starting materials. This afforded 1,1,2,2-tetraphenyldiphosphine monosulfide (1), as well as 1,1,2,2-tetracyclohexyldiphosphine monosulfide (2), which could be used as convenient ligand precursors. Upon addition of 1 or 2 to the ruthenium compound Ru(C₅Me₅)(cod)Cl, the diphosphine monosulfides rearranged to give bidentate bis(ditertiaryphosphino)thioether ligands in Ru(C₅Me₅)(PPh₂SPPh₂)Cl (3) and Ru(C₅Me₅)(PCy₂SPCy₂)Cl (4).