Electrochemical Annulation–Iodosulfonylation of 1,5-Enyne-containing <i>para</i>-Quinone Methides (<i>p</i>-QMs) to Access (<i>E</i>)-Spiroindenes
Hang‐Dong Zuo, Wen‐Juan Hao, Chi‐Fan Zhu, Cheng Guo, Shu‐Jiang Tu, Bo Jiang
Abstract
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 1,6-addition and an I+-mediated ipso-cyclization cascade. Notably, potassium iodide plays the triple role of an electrolyte, a redox catalyst, as well as an iodination reagent.
Topics & Concepts
ChemistryAnnulationEnyneElectrosynthesisReagentCatalysisRedoxIodideElectrochemistryQuinoneSupporting electrolyteCombinatorial chemistryMedicinal chemistryOrganic chemistryElectrodePhysical chemistrySulfur-Based Synthesis TechniquesSynthesis of Indole DerivativesOxidative Organic Chemistry Reactions