Ruthenium(II)‐Catalyzed Homocoupling of Weakly Coordinating Sulfoxonium Ylides via C−H Activation/Annulations: Synthesis of Functionalized Isocoumarins

Abstract Homocoupling of weakly coordinating sulfoxonium ylides was accomplished via ruthenium (II) catalyzed C−H activation process. This strategy provides a convenient, efficient and step‐economic method to access 3‐substituted isocoumarins with good functional group tolerance. The sulfoxonium ylide acts both as the convenient aromatic substrate and the acylmethylation reagent in this transformation. Moreover, the products could be transformed to diverse valuable derivatives. magnified image