P–C versus C–H bond cleavage in coordinated bis(dimethylphosphino)methane: controlled access to either phosphinite or functionalized diphosphine complexes

Treatment of fac-[Mn(CNPh)(CO)3(dmpm)]ClO4(1) with KOH affords neutral phosphinite complex fac-[Mn(PMe2O) (CNPh)(CO)3(PMe3)](2) as a result of P–C bond cleavage on the dmpm ligand, whereas when carrying out the reaction in the presence of iodine the diphosphinoketenimine derivative fac-[MnI(CO)3{(PMe2)2C=C=NPh}](4) is obtained after deprotonation and further functionalization of the central carbon atom of the diphosphine.