Silver-Catalyzed Reaction of Enynals with Alkenes: A Tandem 1,3‑Dipolar Cycloaddition/Cyclopropanation

A silver-catalyzed reaction of enynals
with alkenes to synthesize
a series of polycyclic compounds has been developed. The reaction
occurred smoothly using enynals with electron-deficient alkynes or
terminal alkynes as substrates. The reaction was proposed to proceed
through a tandem 1,3-dipolar cycloaddition/cyclopropanation process.
The preliminary investigations of the asymmetric catalytic version
revealed that the biphosphine ligand could be used as the potential
efficient chiral ligand.