Electrochemical Dehydration of Sulfonic Acids to their Anhydrides

We developed an electrochemical method for sulfonic anhydride synthesis and one-pot derivatization into sulfonamides and mesylates under mild conditions. Aliphatic sulfonic anhydrides were electrogenerated in up to 74% yield. Since isolating these moisture-sensitive intermediates is challenging, the electrolyzed mixture was directly converted into sulfonamides or alkyl sulfonates using amines or alcohols, respectively. This scalable process enables the synthesis of various nitrogen- and oxygen based products in the multi-gram range.