Li + Modified Nanoporous Na+ -Montmorillonite an Efficient Novel Catalytic System for Synthesis of Quinolines

A simple and efficient method for the synthesis of quinolines and polycyclic quinolines using Li+ modified nanoporous Na+-montmorillonite is described. This new nanocatalyst proceeds via Friedlander annulation under solvent-free conditions. It describes our observations about a trend of catalytic activity of Lithium cation in nanoporous Na+-montmorillonite. In this study, several types of 1,3-diketones such as 1,3-cyclohexanedione, 1,3-cyclopentandione, 5,5-dimethylcyclohexandione (dimedone), acetylacetone and ethyl or methyl acetoacetate and 2-aminoarylketones were rapidly converted to the corresponding substitutedquinoline derivatives in good to excellent yields. The simple experimental procedure, solvent-free reaction conditions, good yields, and utilization of an inexpensive and reusable catalyst are the advantages of the proposed method. To the best of our knowledge, this is the first report on the synthesis of quinoline derivatives using Li+ modified in nanoporous Na+-MMT as a novel nanocatalyst under solvent-free conditions.The catalysts can be recovered for the subsequent reactions and reused without any loss of efficiency.