Cascade Cyclization/Amination of para‐Quinone Methides with β‐Ketodinitriles: Synthesis of Polysubstituted Furans

A protocol for the synthesis of trisubstituted furans via phosphoric acid‐catalyzed regioselective cascade cyclization/amination of para‐quinone methides (p‐QMs) with β‐ketodinitriles has been disclosed for the first time. Various kinds of p‐QMs and β‐ketodinitriles can effectively produce the desired polysubstituted furan derivatives in 64–95% yields, demonstrating high atomic economy and their application in the construction of polysubstituted furan heterocycles. Preliminary biological activity assay suggests that these furans have potential anticancer activities.