Difluorocarbene/DMSO: A Polarity-Reversing Reagent Allowing Electrophilic Arene Halogenation with Halides

This study presents an unconventional arene halogenation strategy facilitated by a difluorocarbene precursor in conjunction with a DMSO solvent. The difluorocarbene/DMSO system enables a reversal of halide polarity, generating a key halosulfonium intermediate in situ that engages in electrophilic aromatic substitution with arenes. This method operates under mild and neutral conditions without requiring transition-metal catalysts or conventional reactive halogenating reagents. This study reveals a novel reactivity mode of difluorocarbene and may stimulate efforts to extend the application of the difluorocarbene/DMSO strategy.