Synthesis of 2,3-dihydrofurans via Lewis acid-Catalyzed [4+1] Cycloaddition of Enynones with Sulfoxonium Ylides in Ionic Liquids: A Mild and Green Platform

The zinc-catalyzed [4+1] cycloadddition followed by intramolecular insertion reaction between enynones and sulfoxonium ylides for the synthesis of multisubstituted 2,3-dihydrofurans in ionic liquids is described. This highly efficient and step-economical reaction displays excellent functional group compatibility and stereoselectivity. The reaction media colud maintain high reaction activity even after six cycles.