P–N bond-forming reactions for the synthesis of phosphines

The reactions of dialkylureas and thioureas with chlorodiphenylphosphine yielded ligands of the type {Ph2PN(R)}2C=E, where R = Me or Et and E = O or S. Reaction of the ligands {Ph2PN(Me)}2C=O and {Ph2PN(Et)}2C=O with Pt(II), Pd(II) and Mo(0) resulted in the formation of square planar and octahedral chelate complexes, while {Ph2PN(Et)}2C=O also acted as a bridging ligand when reacted with Au(I). The coordination chemistry of {Ph2PN(Me)}2C=S was less predictable and reaction of the ligand with Pd(II) resulted in P–N bond cleavage and the formation of a five-membered heterocycle. [Continues.]