A dual-role halogen-bonding-assisted EDA-SET/HAT photoreaction system with phenol catalyst and aryl iodide: Visible-light-driven carbon–carbon bond formation

Electron donor–acceptor (EDA) complex-mediated single-electron transfer (SET) is a crucial method for generating carbon radicals. Hydrogen atom transfer (HAT) enables the direct generation of alkyl radicals from alkanes. We report a dual-role EDA-SET/HAT photoreaction system for carbon–carbon bond formation using a phenol catalyst and aryl iodide. This system facilitates a Minisci-type addition of alkyl radicals to arenes. Mechanistic studies revealed that EDA complex formation is mediated by halogen bonding between phenoxide and aryl iodide. Irradiation of the EDA complex with visible light generates an aryl radical, which abstracts a hydrogen atom from an alkane to form an alkyl radical.