Regioselective Synthesis of Annulated Quinoline and Pyridine Derivatives by Silver-Catalyzed 6-endo-dig Cycloisomerization

3H-pyrano[3,2-f]quinoline-3-one, 4-methyl-4,7-phen­anthrolin-3(4H)-one, and 1,3-dimethylpyrido[3,2-d]pyrimidine-2,4(1H,3H)-dione derivatives have been synthesized by hitherto unreported silver-catalyzed 6-endo-dig mode of cycloisomerization from various N-propargylated heterocyclic compounds. The silver-catalyzed reaction provides the synthesis of potential bioactive compounds in excellent yields.