Electrosynthesis of vinyl sulfones from alkenes and sulfonyl hydrazides mediated by KI: An electrochemical mechanistic study

A variety of vinyl sulfones were prepared from alkenes and sulfonyl hydrazides via electrochemical oxidative sulfonylation. The reaction proceeds in an experimentally convenient undivided electrochemical cell equipped with graphite and iron electrodes employing KI as a redox catalyst and a supporting electrolyte. Applying extremely high current density up to 270 mA/cm 2 permits rapid synthesis in a compact reactor and with small surface area electrodes. A possible reaction mechanism was proposed with the use of cyclic voltammetry. It is the combination of anodic and cathodic processes in this reaction that makes it possible to obtain products under mild conditions with yields from moderate to high.