Cationic Platinum(II) Carboxylato Complexes Are Competent in Catalytic Arene C−H Activation under Mild Conditions

A combination of ESI-MS and kinetic studies establishes that the PtII-catalyzed H/D exchange between benzene and acetic acid-d 4 proceeds with high turnover number in acetic acid solution. For the catalytic cycle, the resting state is identified as the cationic (diimine)PtII(acetato)(acetic acid) complex; the turnover-limiting transition state is the dissociative ligand exchange of benzene for acetic acid. The interconversion of η2- and η1-acetato is surprisingly facile, leading to an unexpectedly fast H/D exchange reaction.