Iodine(III)/AlX3-mediated electrophilic chlorination and bromination of arenes. Dual role of AlX3 (X = Cl, Br) for (PhIO)n depolymerization and as the halogen source

Abstract

An efficient chlorination and bromination of arenes mediated by in situ-formed PhI(X)OAlX2 (X = -Cl, -Br), which is proposed as a plausible halogenating species, is described. The proposed dual role displayed by AlX3, enables the Iodosylbenzene [(PhIO)n] depolymerization while also acting as the halogen source by transferring the chlorine or bromine atoms to the iodine(III) center. This process allowed the chlorination and bromination of different arenes and heteroarenes under mild and open flask conditions. To the best of our knowledge, this is the first report describing a dual role of aluminum salts applied to the direct C-H chlorination and bromination of arenes.