Highly Efficient, Facile, Room Temperature Intermolecular [5 + 2] Cycloadditions Catalyzed by Cationic Rhodium(I): One Step to Cycloheptenes and Their Libraries

A cationic rhodium(I) complex―[(C₁₀H₈)Rh(cod)]⁺ SbF₆⁻―catalyzes the remarkably efficient intermolecular [5 + 2] cycloaddition of vinylcyclopropanes (VCPs) and various alkynes, providing cycloheptene cycloadducts in excellent yields in minutes at room temperature. The efficacy and selectivity of this catalyst are also shown in a novel diversification strategy, affording a cycloadduct library in one step from nine commercially available components.