Electrochemical Cross‐Dehydrogenative Coupling between Phenols and β‐Dicarbonyl Compounds: Facile Construction of Benzofurans. Issue 19 (9th March 2020) - Wang, Yandong
Abstract: Preparative electrochemical synthesis is an ideal method for establishing green, sustainable processes. The major benefits of an electro‐organic strategy over that of conventional chemical synthesis are the avoidance of reagent waste and mild reaction conditions. Here, an intermolecular cross‐dehydrogenative coupling between phenols and β‐dicarbonyl compounds has been developed to build various benzofurans under undivided electrolytic conditions. Neither transition metals nor external chemical oxidants are required to facilitate the dehydrogenation and dehydration processes. The key factor in success was the use of n Bu4 NBF4 as the electrolyte and hexafluoroisopropanol as the solvent, which play key roles in the cyclocondensation step. This electrolysis is scalable and can be used as a key step in drug synthesis. On the basis of several experimental results, the mechanism, particularly of the remarkable anodic oxidation and cyclization process, was illustrated. Abstract : Electrifying : A mild electrochemical system was developed for the preparation of benzofurans through cross‐dehydrogenative coupling between phenols and β‐dicarbonyl compounds. This method has good functional‐group compatibility and can serve as a powerful synthetic tool with high synthetic value.