An efficient heterogeneous gold(I)-catalyzed intermolecular cycloaddition of 2-aminoaryl carbonyls and internal alkynes leading to polyfunctionalized quinolines

The first heterogeneous intermolecular cycloaddition of 2-aminoaryl carbonyls and internal alkynes was realized in DMF at 100 °C by using a triphenylphosphine-functionalized MCM-41-supported gold(I) complex [MCM-41-PPh₃-AuCl] and AgOTf as catalysts, yielding a variety of polyfunctionalized quinolines in good to excellent yields. This heterogeneous gold(I) complex could easily be prepared via a simple two-step procedure from commercially available reagents and recovered by filtration of the reaction mixture. The recovered catalyst could be reused at least seven times with almost consistent activity without addition of AgOTf as a cocatalyst.