Visible Light-Driven α-Alkylation of -Aryl tetrahydroisoquinolines Initiated by Electron Donor-Acceptor Complexes.

The visible light-driven α-alkylation of -aryl tetrahydroisoquinolines was initiated through electron donor-acceptor complex photochemistry. The reaction can proceed smoothly without the addition of any photocatalysts, transition-metal catalysts, or additional oxidants. The proposed mechanism was supported by various mechanistic studies, and the reactive open-shell alkyl radicals were generally produced from an alkylamine and underwent radical coupling for alkylating a wide range of -aryl tetrahydroisoquinolines.