Hemilability of P(X)N-type ligands (X = O, N–H): rollover cyclometalation and benzene C–H activation from (P(X)N)PtMe2complexes

The thermolyses of ((tBu)P(O)N)PtMe2 (, (tBu)P(O)N = (di-tert-butylphosphinito)pyridine) and ((tBu)P(N-H)N)PtMe2 (, (tBu)P(N-H)N = (di-tert-butylphosphino)-2-aminopyridine) in benzene-d6 were investigated. With ((tBu)P(O)N)PtMe2, the product of a rollover cyclometalation of the pyridyl ring was observed in 80% yield along with formation of CH4. In contrast, thermolysis of ((tBu)P(N-H)N)PtMe2 resulted in competing rollover cyclometalation and intermolecular benzene C-H activation with production of a mixture of CH4 and CH3D.