Regioselective Organocatalyzed Monochlorination of Arenes with Electrophilic Chlorosulfoniums

This manuscript presents a regioselective chlorination of arenes, yielding almost exclusively the monochlorinated product. It tolerates free hydroxy groups, 1°, 2° and 3° amines, and carboxylic acids, among other polar and nonpolar functional groups, as well as mono‐ and polysubstituted aromatic rings. Additionally, the utilization of chlorosulfonium salts as the chlorinating agent is demonstrated. The method emerges as an alternative to other processes where organic byproducts must be separated from the reaction mixture. In addition, the main byproducts are gaseous materials such as CO and CO2. This publication introduces the application of sulfoxides, oxalyl chloride, and aqueous hydrogen peroxide as the chlorination mixture.