CoFe2O4@SiO2-NH2-CoII magnetic NPs as a novel, inexpensive and highly efficient magnetic nanocatalyst for aldol-condensation reaction

Aldol-condensation as a powerful C-C forming reaction which is used for the synthesis of α,β–unsaturated ketones is an important reaction in the biosynthesis of carbohydrates, and greatnumber of valuable intermediates in organic synthesis [1]. Many solid platform were used forheterogenization of catalysts in the aldol-condensation reactions. Cobalt-ferrite (CoFe2O4)nanoparticle as a magnetic sold support is a good candidate for the immobilization of homogeneouscatalysts. In this study, CoFe2O4 was synthesized from Fe(NO3)3 and Co (NO3)2 inaqueous media. Core-shell nanoparticles (CoFe2O4@SiO2) were prepared by precipitating silicaon the surface CoFe2O4 [2]. In the following step, functionalization of CoFe2O4@SiO2NPs was performed by the treatment with (3-chloropropyl) triethoxysilane and further reactionwith triethylenetetramine to afford aminated CoFe2O4@SiO2 followed by immobilizationof CoII Corresponding heterogeneous magnetic nanocatalyst (CoFe2O4@SiO2-NH2-CoII NPs).(***) The aldol-condensation reaction was investigated in the presence of CoFe2O4@SiO2-NH2-CoII NPs in solvent free conditions at 100 0C and the results shown that the α,ά-bis(substituted-benzylidene) alkanones were synthesized in good to excellent yields