Electrochemical Synthesis of Spiro[4.5]trienones through Radical-Initiated Dearomative Spirocyclization.

A novel and green route has been developed for the electrochemical synthesis of spiro[4.5]trienones through radical-initiated dearomative spirocyclization of alkynes with diselenides. This metal-free and oxidant-free electrosynthesis reaction was performed in an undivided cell under mild conditions. A variety of selenation spiro[4.5]trienones products were prepared in moderate-to-good yields, showing a broad scope and functional group tolerance. Moreover, the developed continuous-flow system combined with electrosynthesis possesses the potential to achieve scaled-up reactions, overcoming the low efficiency of conventional electrochemical scaled-up reactions.