Palladium‐Catalyzed Allenylation/Intramolecular Diels–Alder Reaction of Furans with Propargyl Carboxylates for the Synthesis of Polycyclic Compounds

A highly efficient palladium‐catalyzed cascade reaction of propargyl carboxylates bearing a furanyl group with organoborons was developed. This methodology offers rapid access to polycyclic Diels–Alder cycloadducts in good to high yields. The thus‐formed oxygen‐bridged products were further converted into anthracene derivatives in a chemoselective manner under mild conditions.