Copper‐Catalyzed Remote C5‐Selective Chlorination of 8‐Amidoquinolines Using Sulfonyl Chlorides as Cl Source

PhI(OAc)2-Promoted Site-Selective C-H Chlorination of (Hetero)arenes with p-Toluenesulfonyl Chloride

An efficient and practical system for metal-free catalytic chlorination of (hetero)arenes by using readily available and inexpensive TsCl and PhI(OAc)2 is described. This newly developed protocol has been achieved by the nonsymmetric iodane generated by a combination of PhI(OAc)2 and TsCl. The broad substrate scope, good functional group tolerance, excellent regioselectivity, and short reaction times make this method attractive for the late-stage chlorination of complex drug-like scaffolds.

Copper-catalyzed regioselective C2-H chlorination of indoles with para-toluenesulfonyl chloride

A copper-catalyzed, pyrimidine directed regioselective C-H chlorination of indoles with para-toluenesulfonyl chloride (TsCl) has been developed. The reactions proceeded smoothly in the presence of 20 mol% of Cu(OAc)₂ as the catalyst and TsCl as the chlorine source, delivering C2-chlorinated indoles with structural diversity in moderate to excellent yields. Mechanistic studies suggested that single electron transfer (SET) from Cu(II) to TsCl accompanied by the release of the p-toluenesulfonyl radical and the related Cu(III)Cl species might be involved in the reactions.