Oxidation of alkylaromatics to aromatic ketones catalyzed by metalloporphyrins under the special temperature control method

The aerobic oxidation of alkylaromatics to aromatic ketones catalyzed by metalloporphyrins under the special temperature control method was systematically investigated. Three novel and key points were found to have significant functions in this process, that is, the special temperature control method (initiation at higher temperature and reaction at lower temperature), the synergistic effect of the composite catalysts comprising cobalt and manganese porphyrins, and the amount of catalysts in the reaction. Subsequently, the effects of substitutes on alkylaromatics were also explored under the same conditions. Results showed that alkylaromatic conversions gradually increased from 8.5% to 54.3% with the para-substituents shifting from the electron-donating group to the electron-withdrawing group (i.e., methoxy < hydro < bromo < acyl < nitro). A possible mechanism for this reaction was also proposed.