Transition metal-catalyzed carbocyclization of compounds containing organic π-systems has played an important role in organic syntheses. 1 Both the intermolecular and intramolecular carbocyclization is a powerful method for construction of cyclized compounds that are useful for further synthetic transformation. Among various metals, nickel, ruthenium, cobalt, rhodium, and palladium catalysts have been commonly used for carbocyclizations. 2-4
