AgOTf/I-2-Mediated Cyclization/Cross-Coupling/Isomerization of Enynones with Phosphorus Ylides: An Expedient Route to Stereoselective Synthesis of (E)-2-Alkenylfurans

Ag(I)-catalyzed cascade reactions involving enynone cyclization and cross-coupling with phosphorus ylides have been achieved for the first time. Subsequent treatment of the reaction mixture with I-2 afforded the corresponding (E)-alpha-alkenylfurans in 73-95% yields with excellent stereoselectively. A reasonable mechanism has been proposed.