Enthalpy-Controlled Insertion of a “Nonspectator” Tricoordinate Phosphorus Ligand into Group 10 Transition Metal–Carbon Bonds

Insertion of a tricoordinate phosphorus ligand into late metal–carbon bonds is reported. Metalation of a P^P-chelating ligand (L1), composed of a nontrigonal phosphorous (i.e., P­(III)) triamide moiety, P­(N­(o-N­(Ar)­C6H4)2, tethered by a phenylene linker to a −PiPr2 anchor, with group 10 complexes L2M­(Me)Cl (M = Ni, Pd) results in insertion of the nontrigonal phosphorus site into the metal–methyl bond. The stable methylmetallophosphorane compounds thus formed are characterized spectroscopically and crystallographically. Metalation of L1 with (cod)­PtII(Me)­(Cl) does not lead to a metallophosphorane but rather to the standard bisphosphine chelate (κ2-L1)­Pt­(Me)­(Cl). These divergent reactivities within group 10 are rationalized by reference to periodic variation in M–C bond enthalpies.