Palladium-Catalyzed Intermolecular Oxyvinylcyclization of Alkenes with Alkynes: An Approach to 3‑Methylene γ‑Lactones and Tetrahydrofurans

A novel
chloropalladation-initiated intermolecular oxyvinylcyclization
of alkenes with alkynoic acids or alkynols is developed. This protocol
provides a series of 3-methylene γ-lactone and tetrahydrofuran
derivatives in moderate to excellent yields with high stereoselectivities
in the presence of PdCl2 and CuCl2 or CuCl2·2H2O. Besides a broad substrate scope, this
method has the advantages of mild reaction conditions and easily accessible
starting materials. Furthermore, the construction of C–Cl,
C­(sp2)–C­(sp3), and C–O bonds in
one step was also achieved in this transformation.