A novel visible-light photoredox methodology has been developed by Natarajan, Kim, Yadav, and colleagues for the efficient synthesis of 2-arylbenzothiazoles 99a,b via sequential C-S and C-N bond-forming reactions from thiophenols and nitriles (Schemes 33 and 34) . Under green LED irradiation, eosin Y 18 is excited to its singlet state (eosin Y*), which undergoes reductive SET quenching by a thiophenol derivative, yielding the radical cation A and an eosin Y radical anion. The latter is subsequently oxidized back to its ground state by molecular oxygen, producing a superoxide radical anion (O₂⁻ • ). Radical A is deprotonated by O₂⁻ • to generate the thiyl radical B, which reacts with the carbon atom of the nitrile group to form the iminyl radical C. This intermediate undergoes intramolecular cyclization, followed by hydrogen radical elimination, to produce the benzothiazole 99a .