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.