Carboxylate-Directed Addition of Aromatic C–H Bond to Aromatic Aldehydes under Ruthenium Catalysis

We report that ruthenium complexes effectively catalyzed the carboxylate-directed addition of aromatic C–H bonds to aldehydes. The reactions of aromatic acids with a variety of aromatic aldehydes including unactivated ones proceeded efficiently to give the corresponding isobenzofuranone derivatives in high yields. The combination of ruthenium­(II) complexes with tricyclohexylphosphine led to highly nucleophilic aryl–metal species, which enabled versatile [3 + 2] cycloaddition in the absence of a Lewis acid. This paper also demonstrates the application of supported ruthenium catalysts to the title reaction

Ruthenium-Catalyzed Addition of Aromatic Amides to Internal Alkynes and Subsequent Intramolecular Cyclization for the Atom-Economical Synthesis of Isoindolinones

A selective and atom-economical synthesis of isoindolinones is described. This novel synthetic strategy involves two catalytic reactions: the ruthenium-catalyzed regioselective alkenylation of aromatic C–H bond of aromatic amides with internal alkynes, and subsequent intramolecular cyclization of the resulting alkene with amide functionalities. The addition of only a catalytic amount of bases is required for efficient construction of the desired isoindolinones, and no byproducts are formed in the tandem catalytic reactions. Various kinds of aromatic amides and internal alkynes can be used in the present reactions, and the corresponding isoindolinones bearing a quaternary carbon at the C3 position are obtained in good to high yields