Gold-Catalyzed Hydroalkoxylation/Povarov Reaction Cascade of Alkynols with N-Aryl Imines: Synthesis of Tetrahydroquinolines

A one-pot gold-catalyzed hydroalkoxylation/Povarov reaction cascade of alkynols with N-aryl imines or in situ generated iminium has been developed. The protocol provides a facile access to a series of fused tricyclic tetrahydroquinolines with a broad substrate scope using readily available materials under mild conditions. The unique mechanistic feature is the dual function of the gold catalyst, which first catalyzed the intramolecular hydroalkoxylation of alkynols, and upon the formation of dihydrofuran species, promoted the following Povarov reaction with high stereo-selectivity.