A General Photoredox Platform for the Hydroarylation of Olefins.

Alkene hydroarylation provides a direct strategy for merging aryl groups with alkene-derived C(sp3)-rich fragments, yet general methods that employ abundant aryl bromides across diverse alkene classes remain elusive. Herein, we report XAT-Heck, a radical hydroarylation platform that couples aryl bromides with alkenes under mild photoredox conditions through halogen-atom transfer (XAT)-enabled aryl radical generation. The method accommodates terminal, internal, and gem-disubstituted alkenes, as well as a broad range of heteroaryl and aryl bromides. Chemical-space mapping further supports the broad coverage of commercially available olefin and aryl bromide space. The versatility of this platform is showcased through deuterium incorporation, medium-ring formation, late-stage functionalization, and proteolysis-targeting chimera (PROTAC) library construction.