Three-component, stereoselective palladium-catalyzed synthesis of functionalized bicyclopentanoids

1,5-Cyclooctadiene can be stereoselectively transformed into a substituted bicyclo[3.3.0]octane ring system under palladium catalysis with concomitant formation of three carbon-carbon bonds. Reaction with an aryl iodide or triflate and malonate gives an exo-endo product, while the reaction with a malonate in the presence of oxygen affords a bis-endo adduct.