Electrochemical Direct C−H Halogenation of N‐Heteroarenes and Naphthols.

In this study, we present a straightforward and environmentally friendly electrochemical approach for achieving selective halogenation of N‐heteroarenes, including indoles, diazoles, pyrroles, quinolinone, and naphthols. Our method utilizes commercially available and affordable ammonium halides as halogen source. A library of valuable halogenated N‐heteroarenes can be synthesized in moderate to excellent yields under mild conditions (transition‐metal‐free, oxidant‐free, ethanol as solvent, atmospheric environment). The approach demonstrates a broad substrate scope, excellent tolerance towards various functional groups, and scalability. [ABSTRACT FROM AUTHOR]