Catalysis Letters, Vol.147, No.4, 919-925, 2017
TiO2 Nanoparticles Catalyzed Chemoselective Synthesis of 2-Chloroquinolinyl-4-quinolinones and their Intramolecular Cyclization through Palladium Catalyzed Sonogashira Coupling Reaction
The 2-chloro-3-formyl quinolines 1, were chemoselectivity and effectively converted into their corresponding 2-chloroquinolinyl-4-quinolinones 3 through Knoevenagel condensation/aza-Michael addition utilizing TiO2 nanoparticles. The Sonogashira coupling of 2-chloroquinolinyl moiety of the quinolinone, 3 gave unprecedented cyclised products 1,6-naphthyridines, 5 through cascade reaction in good yields and purity.