Transition-Metal-Free Anti-Markovnikov Hydroarylation of Alkenes with Aryl Chlorides through Consecutive Photoinduced Electron Transfer.

The hydroarylation of alkenes has emerged as a powerful strategy for arene functionalization. However, aryl chlorides remain a large challenge in this type of reaction due to the chemical inertness of the C(sp 2 )-Cl bond and high negative reduction potential. Herein, we report an anti-Markovnikov radical hydroarylation of alkenes with aryl chlorides via visible-light photoredox catalysis. The key reactive aryl radicals can be efficiently achieved from aryl chlorides by consecutive photoinduced electron transfer. This transition-metal-free protocol features mild conditions, a wide substrate scope, and functional group tolerance, producing a diverse range of linear alkylarenes in moderate to good yields. The reaction is proposed to proceed through a radical-polar crossover pathway.