Hypervalent Iodine Mediated Sulfonamide Synthesis

A new metal‐free sulfonylation reaction is described. The method takes advantage of the Umpolung reactivity and group‐transfer properties of iodine(III) compounds, combining hypervalent iodine reagents and sulfinate salts to deliver a clean and mild transfer of sulfonyl groups to amines and anilines. A total of 25 sulfonamides was synthesised in up to 99 % yield, even on gram‐scale. The reaction mechanism was investigated by ESI‐MS and DFT calculations.