Relay Catalysis by Palladium and Brønsted Acid Enables Selective Activation of Cyclopropane for One‐Pot Synthesis of Dihydronaphthofurans From Naphthol Derivatives

This work describes a versatile, one‐pot synthesis of dihydronaphthofuran scaffolds with preferential chemoselectivity and regioselectivity, enabled by a palladium/Brønsted acid cooperative catalytic system. The transformation proceeds via a sequential mechanism: initial Pd(0)‐catalyzed allylic alkylation between naphthalen‐2‐ols (or naphthalen‐1‐ols) and vinylcyclopropane (VCP) dicarboxylates generates a linear allylic intermediate; this is followed by in situ Brønsted acid–promoted intramolecular hydroalkoxylation of the pendant olefin by the phenolic hydroxyl group, affording either 1,2‐dihydronaphtho[2,1‐b]furans or 2,3‐dihydronaphtho[1,2‐b]furans in moderate to good yields (43%–76%). The methodology exhibits a broad substrate scope and excellent functional group tolerance, accommodating both electron‐donating and electron‐withdrawing substituents on the naphthol ring, as well as naphthalene‐1,5‐diols and naphthalene‐1,6‐diols. As an atom‐economical process, it enables naphthols bearing both a C‐nucleophilic and an O‐nucleophilic site to engage in a formal [3 + 2] cycloaddition with VCPs. This operationally simple, tandem protocol thus provides efficient and convergent access to synthetically valuable fused furan scaffolds from readily available, bench‐stable starting materials.