Cycloadditions of 1,1-Disubstituted Benzocyclobutenes Obtained by C(sp3)-H Activation

An efficient synthesis of polycyclic molecules has been performed by a sequence involving palladium-catalyzed C-H activation and [4 + 2] cycloaddition. The intermediate benzocyclobutenes underwent a microwave-enhanced electrocyclic ring-opening/cycloaddition process with complete torquoselectivity and diastereoselectivity.