Reductive-cyclization-mediated syntheses of fused polycyclic quinolines from the Baylis-Hillman adducts of acrylonitrile: Scope and limitations

Abstract

Syntheses of a variety of polycyclic quinolines are described. The target molecules were obtained in two steps through initial reductive cyclization succeeded by another intramolecular cyclization in the allyl amines afforded either from the acetates or the allyl bromides of Baylis-Hillman adducts of 2-nitrobenzaldehydes and acrylonitrile. The two steps proceeded in one-pot for the substrates wherein formyl or hydroxyl group reacted with the amino group of 2-aminoquinoline for second intramolecular cyclization. On the contrary, basic medium was necessary for second intramolecular cyclization in the substrates where alkoxycarbonyl group and the amino-group group participated.