Alumina supported-CeCl3·7H2O–NaI: an efficient catalyst for the cyclization of 2′-aminochalcones to the corresponding 2-aryl-2,3-dihydroquinolin-4(1H)-ones under solvent free conditions

We recently advanced silica gel supported-TaBr5 as an efficient catalyst for the isomerization of 2′-aminochalcones to the corresponding 2-aryl-2,3-dihydroquinolin-4(1H)-ones under solvent free conditions (Tetrahedron Lett. 2006, 47, 2725–2729). This conversion can be further improved through the use of more economic alumina supported-CeCl3·7H2O–NaI, providing high yields of up to 98% at lower reaction temperatures. This stable catalyst is easily prepared, active under solvent-free conditions and employed under environmentally friendly conditions.