Electrochemical One-Step Synthesis of Alkyne Sulfonates and Sulfonamides: Building Blocks for Highly Substituted Alkenes and 1,3-Butadienes.

Alkyne motifs have a central place in organic synthesis due to their versatility as building blocks for complex molecule construction. The development of efficient and sustainable strategies for the synthesis of functionalized alkynes remains an utmost challenge in modern organic chemistry. Herein, we report a novel and efficient electrochemical multicomponent reaction (eMCR) that enables the one-step synthesis of valuable alkyne sulfonates and sulfonamides using SO2 stock solutions and electric current as a clean oxidant. The generated alkynyl sulfonates and sulfonamides serve as powerful synthetic intermediates, undergoing diverse downstream transformations, including regio- and stereoselective copper-catalyzed dimerizations, hydroarylations, and cyclizations, to access 1,3-dienes, highly substituted alkenes, and heterocycles. Moreover, this method enables late-stage functionalization of complex molecules and pharmaceuticals, demonstrating its significant potential for natural product synthesis, medicinal chemistry, and materials science. The study underscores the promise of electrochemical MCRs as sustainable and versatile tools in modern synthetic methodology.