Tandem Cross-Coupling of Alkynyl Sulfides and Alkynyl Sulfoxides/[3,3]-Sulfonium Rearrangement to Construct Tetrasubstituted Furans.

In the presence of boron trifluoride, a variety of alkynyl sulfides and alkynyl sulfoxides undergo tandem cross-coupling/[3,3]-sulfonium rearrangement followed by 5- exo -dig heterocyclization. The strategy provides concise access to novel tetrasubstituted furans in good to high yields with 100% atom-economy efficiency. Further derivatization of the resultant furans was feasible by utilizing the incorporated alkylthio groups.