Rh-Catalyzed [2,3]-Sigmatropic Rearrangement of Alkynyl Carbenes with Allyl Sulfides to Access Sulfide-Substituted 1,5-Enynes

This study describes the development of Rh-catalyzed [2,3]-sigmatropic rearrangement of alkynyl carbenes with allyl sulfides. The protocol exhibits equitable functional group tolerance and allows the formation of a variety of synthetically valuable sulfide-substituted 1,5-enyne products. To the best of our knowledge, this is the first example of [2,3]-sigmatropic rearrangement of alkynyl carbenes. DFT analysis supports the involvement of rhodium carbene generation, sulfonium ylides formation, and [2,3]-sigmatropic rearrangement pathway.