An Eficient One‐Pot Synthesis of 1,4‐Dihydropyridines Catalyzed by Magnetic Nanocrystalline Fe 3 O 4

An efficient approach for one‐pot three‐component reaction of aromatic amines, α,β‐unsaturated aldehydes and β‐keto esters using magnetic nanocrystalline Fe 3 O 4 as a catalyst has been described. The corresponding 1,4‐dihydropyridines are obtained in good yields under mild conditions. In addition, the catalyst can be recovered with a magnet and reused at least five consecutive cycles without appreciable loss of its catalytic activity .