Pd-Catalyzed Spirocyclization via C–H Activation and Benzyne Insertion

A palladium-catalyzed spirocyclization forming spirooxindoles and spirodihydrobenzofurans has been achieved. Mechanistic studies suggest that the transformation proceeds through sequential carbopalladation, C–H activation, and benzyne insertion. Both classes of spirocycles have been synthesized in good to excellent yields, and the procedure is readily scalable