Covalently immobilized Mn(III)deuteroporphyrin on chitosan: An efficient and recyclable catalyst for aerobic oxidation of cyclohexane

Chitosan‐supported Mn(III)deuteroporphyrin chlorine [Mn(III)DPCl‐CTS] catalyst was prepared by convalent binding of Mn(III)deuteroporphyrin‐bearing carboxyl groups on the side chain of the macrocycle ring to chitosan. The supported catalyst was found to efficiently catalyze the hydroxylation of cyclohexane with air as oxygen source. The effect of various reaction parameters, such as reaction time, temperature, and pressure on the catalytic performances, was in detail investigated and the designed installed oxidation equipment was convenient for on‐line sampling during the reaction every time. Under an optimum temperature of 140°C and a pressure of 0.7 MPa, the obtained cyclohexane conversion (16.9%) and chemoselectivity (88.7%) for cyclohexanol and cyclohexanone were much better than those observed with unsupported Mn(III)deuteroporphyrin and synthetic Mn(III) tetraphenylporphyrin. An intermolecular interaction between amino moieties in chitosan and dipropionic groups in Mn(III)deuteroporphyrin was suggested to play a role in the high conversion of this system.