Synthesis of Quinolines and Pyrido[3,2- g or 2,3- g]quinolines Catalyzed by Heterogeneous Propylphosphonium Tetrachloroindate Ionic Liquid.

This report explains an efficient method for synthesis of an array of quinolines via the reaction of 2-aminoaryl ketones with terminal and internal alkynes in the presence of propylphosphonium tetrachloroindate ionic liquid supported on nanosilica (PPInCl-nSiO) as a heterogeneous and reusable catalyst under solvent-free conditions. Inspired by this catalytic system, the first easy one-step synthesis of symmetric and unsymmetric pyrido[3,2- g or 2,3- g]quinolines was investigated through the reaction of diaroylphenylenediamines with one alkyne or two different alkynes.