Efficient syntheses of 2-amino-4H-pyrans via gold-catalyzed cyclization of diester-tethered ynamides

Abstract

Gold-catalyzed intramolecular cyclizations of diester-tethered ynamides are reported herein. This protocol exhibited a high functional group tolerance, broad substrate scope and 100% atom economy. A variety of functionalized 2-amino-4H-pyrans were obtained in up to 95% yield with 0.5-5 mol% catalyst loading. The reaction could be scaled-up and downstream transformations were also performed.