Electrochemical Annulation–Iodosulfonylation of 1,5-Enyne-containing para-Quinone Methides (p-QMs) to Access (E)-Spiroindenes

A new electrochemical three-component annulation–iodosulfonylation of 1,5-enyne-containing para-quinone methides (p-QMs) has been established by using available arylsulfonyl hydrazides and potassium iodide under environmentally benign conditions. The electrosynthesis offers sustainable and efficient access to construct spirocyclohexadienone-containing (E)-indenes without any additional catalyst or oxidant through a sulfonyl-radical-triggered...