A novel method for copper(ii) mediated region-selective bromination of aromatic rings under mild conditions

Abstract

A tridentate N₂O donor Schiff base is used as the substrate and copper(II) perchlorate and potassium bromide have been used as reagents. In the resulting copper(II) Schiff base complex, the 4 position of the aromatic ring of the Schiff base moiety is brominated. X-ray single crystal diffraction study confirms the structure of the complex. In the conventional bromination of aromatic substrates with bromine as the reagent, a potential pollutant hydrobromic acid is produced as a by-product. The present method provides an alternative environmentally friendly route for the bromination of an activated aromatic ring. Regioselectivity of the bromination in the ligand have been studied using DFT calculations.