Mild Three-Step Consecutive C–H Activations

Herein, the Rh-catalyzed consecutive C–H bond olefination/annulation/olefination cascade, tandemly directed by sulfonamide and ester groups, has been developed under mild conditions with the assistance of 1-adamantane carboxylic acid. A seven-membered metallacycle including an ester group was preferred to the five-membered one including a sulfonamide group for the third C–H activation. In this transformation, the Rh catalyst exhibits its high reactivity by catalyzing a triple C–H activation process with a low catalyst loading at 50 °C. This method can be applied in the construction of various pharmaceutical derivatives.