Recyclable catalytic synthesis of substituted quinolines: copper-catalyzed heterocyclization of 1-(2-aminoaryl)-2-yn-1-ols in ionic liquids

A convenient and simple approach for the recyclable catalytic synthesis of substituted quinolines is presented. The method is based on CuCl2-catalyzed heterocyclization of readily available 1-(2-aminoaryl)-2-yn-1-ols in BmimBF4 as the solvent at 100 °C for 15–24 h. The solvent–catalyst system could be successfully recycled up to six times without significant loss of activity.