Construction of 3-Hydroxyindolin-2-ones via Ru(II)-Catalyzed Domino Alkylation/Cyclization/Oxidation of 2-Aminophenethanols

A novel Ru(II)-catalyzed domino reaction, comprising alkylation, cyclization, and oxidation of 2-aminophenethanols with benzyl alcohols, has been developed for the synthesis of 3-hydroxyindolin-2-ones. This transformation exhibits excellent synthetic efficiency, enabling the selective formation of four or three σ bonds, one π bond, and one quaternary carbon center in one step under identical conditions. Furthermore, it provides a versatile approach to 3-hydroxyindolin-2-one frameworks with distinct substituents at the 1- and 3-positions.