Oxidative reactions of tetrahydrobenzimidazole derivatives with N-sulfonyloxaziridines

An investigation of the utility of N-sulfonyloxaziridines to effect the oxidative rearrangement of tetrahydrobenzimidazoles to spiro fused 5-imidazolones is reported. In addition to the anticipated rearrangement manifold, it was found that 2-amino substituted derivatives afford products resulting from rearrangement, or alternatively from addition of methanol or water depending on the nature of the N-substituents and reaction conditions.

Treatment of tetrahydrobenzimidazoles with N-sulfonyloxaziridines leads to the formation of spiro fused 5-imidazolone in moderate to excellent yield.