EDA Complexation of Two Donor Molecules Initiating Radical Cation Cyclizations

Abstract In this study, a catalyst-free EDA complexation of two donor molecules using an acidic solvent is presented. The electron-rich aromatic compound (E)-anethole is slowly protonated by the solvent hexafluoroisopropanol (HFIP), leading to the rapid formation of a photoactive EDA complex between a protonated (E)-anethole and another (E)-anethole molecule. This resulting EDA complex initiates radical chain cyclization reactions under green light irradiation.