Direct Access to 3-Thioether-Substituted Dihydrofuro[2,3- b ]benzofurans via Tandem Reactions of Sulfur Ylides and 2-Nitrobenzofurans.

The synthesis of 3-thioether-substituted dihydrofuro[2,3- b ]benzofurans involving the [3 + 2] coupling of sulfur ylides with 2-nitrobenzofurans has been realized in moderate to good yields under mild conditions without any precious catalysts or additives. It is worth mentioning that the reutilization of the departed nitro-anion in the reaction process facilitates this new chemical transformation and presents a manner of high atom economy to provide products with a complex structure.