Electrooxidative C–H/O–H bond coupling via Ru catalysis: access to phthalides and naphtho[1,8-bc]furans†

We hereby report ruthenium-catalyzed electrooxidative coupling of acrylates with benzoic acids and naphthol for the synthesis of phthalide and naphthofuran derivatives. The process is particularly effective for activating weakly coordinating O–H bonds using ruthenium catalysts. This method is workable and well-organized for the activation of carbon–hydrogen and oxygen–hydrogen bonds, demonstrating moderate to good yields across a diverse set of over 26 readily available substrates. The method proceeds under oxidant- and additive-free conditions, significantly reducing the reaction time while retaining a broad substrate scope. Our approach provides a green and user-friendly method for synthesizing phthalides and naphthofurans via weak coordination O–H and C–H bond activation, leveraging electricity as an oxidant.