Regulation of Photogenerated Redox Species through High Crystallinity Carbon Nitride for Improved C−S Coupling Reactions

Abstract A novel and efficient approach for the synthesis of α, β‐unsaturated sulfones through heterogeneous photocatalyzed C−S coupling reactions have been developed. The use of molten‐salt method derived carbon nitride (MCN), a transition metal‐free polymeric photocatalyst, combined with enhanced crystallinity and potassium iodide as an additive, effectively modulates photogenerated reactive redox species, markedly increasing the overall reaction selectivity. This method achieves the shortest reaction time (2 h) with high yield (up to 95 %) among the reported heterogeneous catalytic C−S bond formation reactions, matching the efficiency of the homogeneous photocatalysts. Furthermore, the application to challenging alkyne substrates has been demonstrated, underscoring the potential for a broad range of applications in pharmaceutical research and synthetic chemistry.