Hypervalent N-sulfonylimino-lambda(3)-bromane: active nitrenoid species at ambient temperature under metal-free conditions.

The synthesis and reactions of N-triflylimino-lambda(3)-bromane are summarized. The hypervalent iminobromane functions as a highly active nitrenoid species at ambient temperature under transition metal-free conditions, probably because of the increased hypernucleofugality of aryl-lambda(3)-bromanyl groups compared to that of aryl-lambda(3)-iodanyl groups. The imino-lambda(3)-bromane undergoes stereospecific aziridination of olefins and transylidation to aromatic nitrogen heterocycles, trialkylamines and iodobenzenes. Difluoro-lambda(3)-bromane-induced Hofmann rearrangement of primary arylsulfonamides is also discussed.