Tandem Palladium-Catalyzed C–H Activation of Biaryls and Ring Opening of Benzofurans: Access to 2-(9-Phenanthryl)phenol Derivatives

A palladium-catalyzed annulation of 2-iodo-1,1'-biaryl substrates, featuring concurrent ring opening of benzofurans, has been established to provide a direct and modular approach for the synthesis of a wide array of phenanthrene derivatives in moderate to good yields. The practicability of this new approach for constructing phenanthrene frameworks bearing phenol motifs has been demonstrated on a gram scale and highlighted by its broad substrate scope and excellent functional group tolerance.