Electrochemical Three‐Component Synthesis of Heteroaryl Sulfonates

An electrochemical three‐component reaction for the synthesis of heteroaryl sulfonates from heteroarenes, SO 2 , and alcohols is described. The metal‐free protocol uses inexpensive graphite electrodes and practical SO 2 stock solutions to achieve a direct C( sp 2 )─H sulfonation of different electron‐rich heterocycles under mild conditions. Thereby, this strategy provides direct access to the heteroaryl sulfonate scaffold from simple building blocks. Application to different electron‐rich five‐membered heterocycles, scalability, and electrode/electrolyte reusability highlight the potential of this process for a sustainable synthesis of heteroaryl sulfonates with relevance to medicinal and synthetic chemistry.