Palladium-catalyzed double strain-release (3 + 3) cycloaddition for the synthesis of vinylbicyclo[3.1.1]heptanes

A protocol for synthesizing all-carbon bicyclo[3.1.1]heptanes (BCHeps) through palladium-catalyzed dipolar (3 + 3) cycloadditions of bicyclobutanes (BCBs) with vinylcyclopropanes has been developed.