Acetylacetone as oxygen activator to improve efficiency for the aerobic oxidation of toluene and its derivatives by cobalt meso- tetraphenylporphyrin
The activation of dioxygen is the major challege in the catalytic oxygenations of hydrocarbon undre mild conditions. In this study, catalytic efficiency for the aerobic oxidation of toluene and its derivatives by cobalt meso-tetraphenylporphyrin was enhanced by using acetylacetone as oxygen activator. The influences of reaction conditions such as solvent, different metalloporphyrins catalyst, temperature, pressure and acetylacetone loading were studied, as well as the kinetics of the oxidation. Various toluene’s derivates could also be oxidized to corresponding products in satisfactory yields with this catalytic system. Based on the characterization of in situ EPR (Electron Paramagnetic Resonance) and in situ UV–vis spectroscopy, the catalytic mechanism was also proposed, in which acetylacetone served as the key inititor of free radical in activating dioxygen.