Access to the first (iminophosphoranyl)(selenophosphoranyl)methane ligands Ph2P(=Se)CH2P(=NR)Ph-2: coordination of their methanide and methandiide anions to ruthenium

A family of mixed (iminophosphoranyl)(selenophosphoranyl)methane ligands of general composition Ph2P(=Se)CH2P(=NR)Ph-2 have been synthesized by oxidation of Ph2PCH2P(=NR)Ph-2 with elemental selenium. In the presence of Et3N, these ligands react with [{RuCl(mu-Cl)(eta(6)-p-cymene)}(2)] to afford mononuclear Ru(II) species in which the resulting methanide anions adopt a tridentate coordination. Further deprotonation with KH generates carbenic ruthenium derivatives which participate, under remarkably mild conditions, in C-C coupling processes with isocyanides.