Amine organocatalysts for highly ortho -selective chlorination of anilines with sulfuryl chloride.

A metal catalyst free approach for regioselective ortho -chlorination of anilines has been developed using a secondary amine as the organocatalyst and sulfuryl chloride as the halogen source under mild conditions. A wide range of substrates were compatible with this catalytic system. In addition, this catalytic protocol has been applied to the efficient synthesis of bioactive compounds and modification of drug derivatives. Further studies indicated that the anionic trichloride species was responsible for the ortho -selectivity.