Silver-catalyzed tandem 5- and 6-endo-cyclizations via concomitant yne-ol-imine activation: selective entry to 2-aryldihydrofuroquinolines

Abstract

A silver(I) catalyzed domino imination-intramolecular biheterocyclization-aromatization cascade has been developed to construct 2-aryl/-heteroaryl dihydrofuroquinolines in moderate to good yield using an aldehyde and unprotected 4-(2-aminophenyl)but-3-yn-1-ol as precursors. Sequential Ag-(I)-induced 5-endo-dig cyclization of the yne-ol part and 6-endo-trig cyclization of a proposed Ag-bound imine, followed by aromatization, furnish the furoquinoline derivatives.