Visible‐Light‐Promoted Iron‐Catalyzed Atom Transfer Radical Addition for the Chlorosulfonylation of Alkenes

Herein, we present an iron‐catalyzed atom transfer radical addition (ATRA) reaction. The approach exhibits low catalysis loading, broad substrate scope, and high atom economy through the use inexpensive and readily available reagents. Notably, this operationally simple strategy provides an alternative to conventional Ru, Ir, and Cu‐photocatalyzed ATRA reactions, and mechanistic studies via intermediate interceptions elucidate the critical role played by the catalysis in directing the transformation. The robustness and synthetic utility were further demonstrated by the late‐stage functionalizations and gram‐scale reactions, which highlighting its value for industrial applications.