Gold-Catalyzed syn-1,2-Difunctionalization of Ynamides via Nitrile Activation.

Developed is an unprecedented Au(I)-catalyzed syn-1,2-difunctionalization of ynamides with 2-aminobenzonitriles via nitrile activation. The coupling between ynamides and 2-aminobenzonitriles is explicitly regioselective, providing a straightforward access to 2,4-diamino-substituted quinolines. Density functional theory (DFT) study provides insightful information and rationalizes the reaction pathway. It shows how the synergy between ynamide π-activation and nitrile σ-coordination by the Au(I) catalyst makes the cyclization viable.