Synthesis of Sulfonyl Chlorides from Aryldiazonium Salts Mediated by a Heterogeneous Potassium Poly(heptazine imide) Photocatalyst

Visible light photocatalysis is a tool in synthetic chemistry that allows us to utilize the energy of photons via photoinduced electron transfer to promote diverse organic reactions. Herein, a heterogeneous transition metal-free material, a type of carbon nitride photocatalyst, potassium poly(heptazine imide), is employed to produce sulfonyl chlorides from arenediazonium salts under mild conditions (visible light irradiation, room temperature) with 50-95% yields. The method is suitable for the synthesis of both electron rich and electron deficient compounds, and it shows high tolerance toward different functional groups (halides, ester, nitro, cyano groups). Thus, a sustainable photocatalytic alternative to the Meerwein chlorosulfonylation reaction is offered.