Secondary Amine‐Mediated Domino Reaction for the Synthesis of Substituted Quinolines from Dicyanoalkenes and Enynals.

Substituted quinolines, tricyclic and tetracyclic molecules with a quinoline moiety are synthesized by a domino reaction from dicyanoalkenes and 3‐aryl‐pent‐2‐en‐4‐ynals in one pot. We established two methods: one is catalyzed by chiral diphenylprolinol silyl ether, and the other is catalyzed by di(2‐ethyl)hexylamine, in combination with p‐nitrophenol. A wide variety of dicyanoalkenes can be employed. As the catalysts are secondary amines, and water is the only by‐product, this is an environmentally benign synthetic method for the preparation of substituted quinolines. [ABSTRACT FROM AUTHOR]