One pot synthesis of five substituted tetrahydropyridines using nano- Al2O3/BF3/Fe3O4 as a highly efficient nano-catalyst

The five-substituted tetrahydropyridines and their derivatives have an interesting class of pharma actives [1] such as anticancer [2], antibacterial [3] and antihypertensive[4] activities. Because of these potent pharmaceutical properties of the tetrahydropyridines chemistry, a faster, milder and more ecofriendly methods accompanied with higher yields is needed [5]. Although the homogeneous catalysts are efficient but separation of them are so difficult. An important advantage of heterogeneous catalysts is that they can be easily separated and reused from the reaction. For this reason, one pot multicomponent reactions of aromatic aldehydes, anilines and β-keto-esters under solvent free conditions were studied in the presence of nano-Al2O3/BF3/Fe3O4 catalyst. This nanomagnetic catalyst is easily isolated at the end of the reaction by using an external magnet without any filtration.(Fig1)