Aerobic Selective Oxidation of Cyclohexylbenzene over Organocatalysis with Pairs of Nitrogenous Hydroxyl Precursors and Anthraquinones

Selective oxidation of cyclohexylbenzene is a potentially promising process in industrial application. Herein, we reported an organocatalytic system to achieve the selective oxidation of Cα–H bonds in cyclohexylbenzene and transformation of active intermediate Cα peroxide by an oxidation then decomposition method. The pair of N-hydroxyphthalimide and 2-Chlorothraquinone (NHPI/AQ-Cl) as metal-free organic catalysts showed the highest efficient in selective oxidation of cyclohexylbenzene to Cα peroxide and Cα alcohol. And the base modified covalent triazine frameworks could facilitate the Cα peroxide decomposition to the Cα alcohol. Up to 8.8% conversion of substrate and 80% selectivity of 1-phenylcyoclohexanol were achieved under the optimized conditions. This work provided a new organocatalytic strategy to achieve the aerobic selective oxidation of Cα–H bonds in cyclohexylbenzene.