Oxidation reactions using polymer-supported 2-benzenesulfonyl-3-(4-nitrophenyl)oxaziridine

A thermally stable polymer-supported oxidant has been developed. Polymer-supported 2-benzenesulfonyl-3-(4-nitrophenyl)oxaziridine was applied to microwave-assisted reactions that occurred at high temperatures and was shown to oxidize alkenes, silyl enol ethers, and pyridines to the corresponding epoxides and pyridine N-oxides in excellent to good yields and with much shorter reaction times. It also enabled tetrahydrobenzimidazoles to be oxidatively rearranged to Spiro fused 5-imidazolones in a more efficient manner. Recycling of the polymer-supported oxidant is also possible with minimal loss of activity after several reoxidations. (C) 2011 Elsevier Ltd. All rights reserved.