Synthesis of 3-Substituted 2-Aminochromones via Sn(IV)-Promoted Annulation of Ynamides with 2-Methoxyaroyl Chlorides

A Sn(IV)-promoted annulation reaction of ynamides is described for the efficient synthesis of 3-substituted 2-aminochromones under mild conditions. This novel method allows for a concomitant construction of C-C and C-O bonds between ynamides and 2-methoxyaroyl chlorides by a tandem Friedel Crafts acylation/oxo-Michael addition/elimination strategy.