Applicability of Semiconductor Photocatalysts in Photoredox Reactions: Highlighting the Performance of Polymeric Carbon Nitrides in Radical Three‐Component Couplings

Abstract A set of five polymeric carbon nitrides (pCNs) made from diverse low‐molecular precursors was compared with metal chalcogenide and pnictogenide semiconductors for their effectiveness in visible light‐induced organic radical reactions. The productivity of the heterogenous photocatalysts in the decarboxylative Giese addition of N ‐phenylglycine with cyclopentenone was studied at different irradiation wavelengths ranging from 380 to 450 nm, as well as in the deaminative radical donor–acceptor–donor (DAD) three‐component coupling of N ‐benzyl pyridinium salts with N ‐methylmaleimide and 1,1‐diarylethylenes. The heterogenous photocatalytic radical three‐component reactions were achieved in high diastereoselectivities and with high yields if the electronic and steric properties of the reactants were matched with the appropriate heterogeneous photocatalyst.