l-Proline-catalyzed synthesis of 2-aryl-2,3-dihydroquinolin-4(1H)-ones in ionic liquids

The synthesis of 2-aryl-2,3-dihydroquinolin-4(1 H )-ones from aromatic aldehydes and and 1-(2-aminophenyl)ethanone catalyzed by l -proline in ionic liquids was achieved for the first time. High yields up to 88.7% were achieved. Mild reaction conditions, enhanced rates, improved yields, and reagents’ reactivity, which is different from that in standard organic solvents, are the remarkable features observed in ionic liquids. In addition, the reaction mechanism was studied using computational methods, and the results were consistent with experimental findings. Graphical abstract