Visible Light‐Mediated C−H Monofluoromethylation of (Hetero)arenes

The monofluoromethyl group (‐CH₂F) is an important structural unit that is widely present in many drug molecules and bioactive molecules. Due to the scarcity of monofluoromethylation reagents, the development of the direct monofluoromethylation reaction of (hetero)arenes has been slow. We report the design and application of a monofluoromethylation reagent: 1‐((bromofluoromethyl)sulfonyl)‐4‐chlorobenzene. By taking advantage of the electron‐withdrawing property of the sulfonyl group, the polarity of the monofluoride radical can be regulated; moreover, the sulfonyl group's facile removability is exploited. These combined features enable direct monofluoromethylation of (hetero)arenes under mild visible‐light conditions.