Indium(III)‐Catalyzed Three Component Reaction of N‐Bromosuccinimide, Alkenes and N‐Tosylhydrazones.

A three‐component reaction involving alkenes, N‐sulfonylhydrazones, and N‐bromosuccinimide (NBS) is described that uses Indium(III) triflate for the synthesis of bromoethyl sulfonyl hydrazones. Using N‐tosylhydrazones as a nitrogen source and NBS as a bromine source, this intermolecular aminobromination of alkenes is carried out under air in mild conditions. A mechanism of electrophilic addition is proposed based on the GC‐MS analytical result. [ABSTRACT FROM AUTHOR]