Substituent Effects in Arylseleninic Acid-Catalyzed Bromination of Organic Substrates with Sodium Bromide and Hydrogen Peroxide

Abstract

Arylseleninic acids were found to be catalysts for the oxidation of bromide with hydrogen peroxide in a two-phase mixture of ether and pH 6 phosphate buffer. Benzeneseleninic acid (3) and 4-methoxyphenylseleninic acid (4) were more efficient catalysts than 3,5-bis(trifluoromethyl)phenylseleninic acid (1), 4-nitrophenylseleninic acid (2), 4-dimethylaminophenylseleninic acid (5), and 2,4,6-trimethylphenylseleninic acid (6). A variety of organic substrates were efficiently brominated under these conditions using 5−10 mol % of commercially available benzeneseleninic acid (3).