SILICA-SUPPORTED 4-OH-TEMPO/NOX: A NOVEL AND EFFICIENT CATALYST FOR AEROBIC OXIDATION OF ALCOHOLS

Silica-supported 4-OH-2,2,6,6-tetramethylpiperidyl-1-oxy/NOx (4-OH-TEMPO was immobilized on the surface of silica using the sol-gel method, and then it adsorbed NOx), as a heterogeneous catalyst, has exhibited good catalytic performance in alcohol oxidation. A broad range of alcohols were oxidized to their corresponding aldehydes or ketones with more than 99% selectivity and 99% conversion rate by such a catalyst system at room temperature in air. NOx not only acted as an electron bridge between O-2 and 4-OH-TEMPO but also were conducive to the formation of the aldehydes as active component. A possible mechanism for oxidation of alcohols promoted by silica-supported 4-OH-TEMPO/NOx was supposed. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications (R) for the following free supplemental resource(s): Full experimental and spectral details.]