With the photocatalyst 4CzIPN 23 under blue LED light, an oxidant-free protocol was developed for synthesizing ether-functionalized benzothiazoles 72 from 2-isocyanoaryl thioethers (Scheme 25) . Photoexcitation of 4CzIPN produces its excited state (4CzIPN*), which accepts an electron from tetrahydrofuran (THF) to generate an α-oxy radical A and the reduced form of the photocatalyst. Radical A reacts with the isonitrile substrate to form the imidoyl radical intermediate B, which undergoes cyclization to produce the benzothiazole product 72 and a methyl radical. The methyl radical combines with a proton to form methane, driven by the photocatalyst-mediated oxidative quenching process. Scheme 25. A photocatalyst-and transition-metal-free synthesis of benzothiazoles 72.