Oxidative Addition of Haloalkanes to Metal Centers: A Mechanistic Investigation

Photolysis of CpRe­(CO)3 in the presence of dichloromethane results in the initial formation of the CpRe­(CO)2(ClCH2Cl) complex followed by insertion of the metal into the C–Cl bond. The activation enthalpy is determined to be 20.4 kcal/mol, and with the assistance of DFT calculations, a radical mechanism is proposed for the oxidative addition reaction. Photolysis of Ni­(CO)2(PPh3)2 with dihalomethanes also results in oxidative addition, but the intermediacy of a halogen-bound adduct has not been established.