Solvent-free selective oxidation of benzylic compounds over chromium containing mesoporous molecular sieve catalyst at 1 atm O2

Solvent-free selective oxidation of benzylic compounds was effectively performed over chromium containing mesoporous molecular sieve (CrMCM-41) catalyst at 1 atm O2 under mild reaction conditions (<100 °C). A variety of benzylic compounds such as cycloalkyl (tetralin, indane, diphenylmethane and fluorene) and alkylbenzenes (e.g., ethylbenzene, propylbenzene and n-butylbenzene) were studied. These compounds were selectively oxidized giving the corresponding benzylic ketones with excellent selectivity (82–98%) and good yield (23–60%). Under these solvent-free reaction conditions without the use of hydroperoxide oxidant, catalyst can be recycled.