Various alkenes (internal, terminal, aryl and alkyl substituted) and 1,2-diphenylethyne were efficiently and selectively dibrominated using 2 equivalents of 48% aqueous hydrobromicacid, with air as an oxidant and sodiumnitrite as a catalyst. Despite the presence of water, only trans dibromination occurred producing anti-1,2-dibromoalkanes and (E)-1,2-dibromo-1,2-diphenylethene. A comparison of resource