Selective Aerobic Peroxidation of Styrene Catalyzed by a Cobalt -Butylperoxo Complex.

Selective oxidation of styrene to desired products is essential and challenging. In this study, we elucidate a unique pathway for the selective oxidation of styrene to polystyrene peroxo species, catalyzed by the cobalt(III) -butylperoxo complex, [Co(OO Bu)(qpy)(NCCH)] (), under ambient conditions. Mechanistic investigations, including the structural determination of the diperoxo complex, [Co(qpy)(OOCH(Ph)CHOO Bu)(NCCH)] (), by X-ray analysis and theoretical calculations reveal that the reaction begins with the nucleophilic addition of styrene to the Co-OO Bu moiety in . This step is followed by an addition with an O molecule, forming a diperoxyl radical (PhCOO(H)CHOOBu), which subsequently rebounds with Co(qpy) to yield . In the presence of excess O, complex can further react with additional styrene molecules, leading to the formation of cobalt(III) polystyrene peroxo species.