Redox‐Neutral Electrochemical <i>Cis</i> ‐Cyclopropanation of Alkenes With Sulfoxonium Ylides

Herein, we report an efficient metal-free and redox-neutral electrochemical strategy for the cis-selective cyclopropanation of less active alkenes with sulfoxonium ylides. This protocol circumvents the limitations of traditional methods, which are typically restricted to electron-deficient alkenes, and provides access to thermodynamically less stable cis-cyclopropanes. Furthermore, the resulting cyclopropanes can be readily diverted to hydroalkylation products via controlled cathodic reductive ring-opening. Mechanistic studies support a radical cation-mediated stepwise cycloaddition pathway, wherein the cis-diastereoselectivity is established during the initial radical addition. This sustainable approach not only broadens the synthetic utility of sulfoxonium ylides but also represents a significant advance in green electrochemical synthesis.