Tribromoisocyanuric Acid as a Green Cohalogenating Reagent: An Efficient Transformation of Alkynes into α,α-Dibromoketones and Vicinal Dibromoalkenes

The co-halogenation reaction of alkynes with tri-bromoisocyanuric acid in acetic acid, followed by aqueous work-up produced α,α-di-bromoketones (44-84%), while the reaction in aqueous acetonitrile in the presence of KBr produced vicinal di-bromoalkenes (66-86%). The usefulness of the methodology was demonstrated employing green metrics for the comparison of TBCA with analogous N-halo reagents in co-halogenation reactions of alkynes.