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

Org Biomol Chem. 2022 Jun 15;20(23):4815-4825. doi: 10.1039/d2ob00758d.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Chlorides
  • Copper* / chemistry
  • Halogenation*
  • Indoles / chemistry

Substances

  • Chlorides
  • Indoles
  • Copper