Nitrogen-Enriched Biguanidine-Functionalized Cobalt Ferrite Nanoparticles as a Heterogeneous Base Catalyst for Knoevenagel Condensation under Solvent-Free Conditions

Designing efficient, economical heterogeneous catalystsfor theKnoevenagel condensation reaction is highly significant owing to theimportance of reaction products in industries as well as pharmaceutics.Herein, we have designed and synthesized biguanidine-functionalizedbasic magnetically retrievable cobalt ferrite nanoparticles (CFNPs)for the synthesis of Knoevenagel condensation products using benzaldehydesand active methylene compounds (malononitrile/ethyl cyanoacetate/cyanoacetamide).Several advanced techniques, such as Fourier transform infrared (FT-IR),thermogravimetric analysis (TGA), powder X-ray diffraction (XRD),scanning electron microscopy (SEM), transmission electron microscopy(TEM), and vibration sample magnetometry (VSM), were utilized to preciselycharacterize the catalyst. The robust features of the current approachinvolve outstanding catalytic performance, solvent-free reaction conditions,ease of catalyst retrievability, easy workup procedure, large substratetolerance, high turnover frequency (TOF) values (up to 486.88 h(-1)), values of green chemistry metrics such as E-factor(0.15), reaction mass efficiency (RME) value (87.07%), carbon efficiency(93.4%), and atom economy (AE) value (88.10%) close to their idealvalues, and recyclability up to eight runs without a considerablereduction in activity, boosting the appeal of this approach from acommercial and ecological point of view.