Electrochemical/I– Dual-Catalyzed Access to Sulfonated Pyrazoles under External Oxidant-Free Conditions

An electrochemical/I– dual-catalyzed access to sulfonated pyrazoles from pyrazolones and sodium sulfites under external oxidant-free conditions has been developed. This established electrochemical reaction works smoothly under external oxidant-free conditions and has the advantages of good functional group tolerance, easy to gram-scale synthesis, delivering up to 95% yield for 35 examples.