The Different Faces of Photoredox Catalysts: Visible-Light-Mediated Atom Transfer Radical Addition (ATRA) Reactions of Perfluoroalkyl Iodides with Styrenes and Phenylacetylenes

A photoredox-catalyzed procedure for the iodoperfluoroalkylation of styrenes and phenylacetylenes using readily available copper phenanthroline catalyst is reported. In contrast to commonly employed Ru(bpy)3Cl2, Ru(phen)3Cl2 or fac-Ir(ppy)3, Cu(dap)2Cl is capable to convert styrenes to the corresponding perfluoroalkyl tagged ethylbenzenes, pointing toward an additional role of the copper catalyst beyond photoinduced electron transfer. An inner sphere catalytic cycle involving Cu(III) intermediates or ligand abstraction from a CuI+ intermediate is proposed.