One-Pot Synthesis of 1,2-Dihydropyridines: Expanding the Diverse Reactivity of Propargyl Vinyl Ethers

The catalyzed synthesis of 1,2-dihydropyridines starting from easily accessible propargyl vinyl ethers was realized. The reaction sequence involving a transition metal-catalyzed propargyl-Claisen re-arrangement; a condensation step, and a Bronsted acid-catalyzed heterocyclization furnishes the highly substituted heterocycles in moderate to excellent yields. Additionally, a practical one-pot protocol toward 1,2-dihydropyridines and 2H-pyrans starting from propargylic alcohols was developed.