Transition-metal-catalyzed [2 + 2 + 2] cycloaddition of alkynes represents a versatile method for the construction of benzene rings. 1 It is especially useful when the desired substitution pattern is not easily built via conventional aromatic substitution reactions. The challenge of implementing this cyclization strategy, however, arises in performing the reactions of unsymmetrical alkynes due to the formation of different regioisomers. Typically, [2 + 2 + 2] cycloaddition of a ...