Doyle−Kirmse Reaction of Allylic Sulfides with Diazoalkane-Free (2-Furyl)carbenoid Transfer

[reaction: see text] In the presence of rhodium catalyst, (2-furyl)carbenoids generated from conjugated ene-yne-carbonyl compounds 1 efficiently undergo carbene transfer reactions with allylic sulfides followed by [2,3]sigmatropic rearrangement of sulfur ylides to give furan-containing sulfides in good yields. When diallyl sulfide is employed, heteroatom-containing polycyclic compounds are obtained by sequential intramolecular Diels-Alder cyclization reaction with a constructed furan ring as an enophile.