Selective 1,1- and 1,2-Dibromination of the Phenylethanes in the Presence of NaBr/NaBrO3/H2SO4 as the Bromination Reagent

Selective 1,1- and 1,2-dibromination of the phenylethanes by simply adjusting the reaction conditions has been developed. Mixtures of NaBr/NaBrO3/H2SO4 are employed as the green bromination reagent, which can release Br2 or BrOH in-situ as required without polluting the environment. Both the resulting 1,1- and 1,2-dibromoethyl arenes can be easily transformed to phenylacetylenes via elimination under basic conditions, demonstrating great potential for industrial application.