Photochemical arylation reactions mediated by a terpyridine cobalt complex

The complex [Co(4'-MeO-tpy)2](PF6)2 effectively mediates the visible-light-driven arylation of pyrroles, 1,3,5-trimethoxybenzene and bis(pinacolato)diborane. Mechanistic studies suggest the reaction likely proceeds through a halogen atom transfer mechanism facilitated by an α-aminyl radical. This work emphasizes the potential of optimizing the ligand framework and reaction conditions to enhance the application of earth-abundant transition metal complexes in photoredox catalysis.