Selective Monoarylation of Aromatic Ketones and Esters via Cleavage of Aromatic Carbon–Heteroatom Bonds by Trialkylphosphine Ruthenium Catalysts

We report here the ruthenium-catalyzed selective monoarylation of aromatic ketones bearing two ortho carbon–heteroatom (O or N) bonds. Under the newly developed catalyst system consisting of RuHCl­(CO)­(P i Pr3)2, CsF, and styrene, the C–O arylation of 2′,6′-dimethoxy­acetophenone with a phenyl­boronate gave the C–O monoarylation product selectively. The selective C–O monoarylation was applicable to a variety of arylboronates and aromatic ketones and proceeds with high regio- and chemoselectivities. A formal synthesis of altertenuol was also achieved using the C–O monoarylation of an aromatic ester as a key step.