CoFe2O4@SiO2-NH2-CoII NPs catalyzed Hantzsch reaction as an efficient, reusable catalyst for the facile, green, one-pot synthesis of novel functionalized 1,4-dihydropyridine derivatives

Abstract

A magnetically heterogeneous CoFe2O4@SiO2‐NH2‐CoII nanoparticle was synthesized by the immobilization of Co (II) complex onto CoFe2O4@SiO2 nanoparticles, and the heterogeneous magnetic nanocatalyst was characterized by XRD, TEM, TGA, EDX, and FT‐IR techniques. Then, the green and reusable method was introduced for a multicomponent synthesis of 1,4‐dihydropyridine derivatives via Hantszch reaction. The synthesis of 1,4‐dihydropyridine derivatives was proceeded by the reaction of aldehyde, ethyl acetoacetate, and ammonium acetate in the presence of this magnetic nanocatalyst in EtOH/Water (1:1). Simple work‐up, short reaction times, excellent yields (60–96%) as well as green solvent are some advantages of this novel approach, and the corresponding products were purified with no need for chromatographic separation.