Selectfluor-promoted electrophilic aromatic halogenation: a general strategy for iodination and bromination via oxidative halide activation

Abstract

Aryl iodides are indispensable intermediates in organic synthesis, yet direct C–H iodination of electronically diverse arenes under mild conditions remains challenging. Herein, we disclose a general and operationally simple C–H iodination protocol leveraging the I₂/Selectfluor system, with Sc(OTf)₃–HFIP activation enabling efficient iodination of electron-deficient arenes. This method exhibits broad substrate scope, accommodating diverse functional groups, heteroarenes, and complex drug-like molecules. Control experiments support a mechanism wherein activation of I₂ by Selectfluor generates a highly electrophilic iodonium species for iodination. Moreover, a related LiBr/Selectfluor system enables efficient C–H bromination of (hetero)arenes under similarly mild conditions.