Expeditious Synthesis of Pyrano[2,3,4‐ de ]quinolines by a Copper(I)‐Catalyzed Cascade Sonogashira Coupling/Annulation Reaction

Pyrano[2,3,4‐ de ]quinoline‐encompassing scaffolds are high‐value, intricate synthetic targets that are of interest in medicinal chemistry. Herein, we illustrate the first example of a copper(I)‐catalyzed cascade Sonogashira coupling/annulation reaction of ethyl 4‐(benzoyloxy)‐5‐bromo‐6‐methylquinoline‐3‐carboxylate with internal alkynes. This methodology exhibits broad substrate scope with respect to the alkyne, with good functional‐group compatibility and promising yields.