Electrochemical Synthesis of Selenated Isochromene-1-carbonitriles via the Cyanation and Selenocyclization of 2-Ethynylbenzaldehydes

An electrochemical strategy for the synthesis of selenated isochromene-1-carbonitriles via the cyanation and selenocyclization of 2-ethynylbenzaldehydes has been developed. These three-component reactions proceed efficiently in an undivided cell at room temperature under metal- and oxidant-free conditions by utilizing diselenides as the selenylation reagents and trimethylsilyl cyanide (TMSCN) as the cyanation reagent. This method exhibits a broad substrate scope and excellent functional group tolerance, enabling the preparation of a variety of isochromenes bearing both Se and CN groups in good to excellent yields. The practical utility of this approach is further highlighted by its scalability to gram-scale synthesis and product derivatization.