Metal-free oxidative brominationreactions in aqueous media were performed using tetrabutylammonium bromide, trifluoroacetic acid, and hydrogen peroxide under mild conditions. Oxidative brominationreaction of alkenes was found to afford the corresponding vic-bromides. Furthermore, this oxidative brominationsystem is applicable to the oxidative bromination of alkynes, arenes, and 3,4-dihydronaphthalen-1(2H)-one