An efficient and eco-compatible multicomponent synthesis of 2,4,5-trisubstituted imidazole derivatives using modified-silica-coated cobalt ferrite nanoparticles with tungstic acid

The aim of this study has been to offer a method for the synthesis of 2,4,5-trisubstituted imidazole derivatives based on green chemistry principles. Therefore, a one-pot multicomponent cyclocondensation reaction through aldehyde interaction with ammonium acetate and 1,2-diketone under solvent-free conditions was utilized as an eco-effective synthetic route using CoFe₂O₄@SiO₂@(-CH₂)₃OWO₃H NPs as the catalyst. The stabilized tungstic acid on 3-chloropropyl-anchored SiO₂-coated CoFe₂O₄ magnetic nanoparticles was designed, prepared, and applied as a recyclable heterogeneous acid catalyst to attain high product yield in a short reaction time. The nanocatalyst structure was confirmed using FT-IR, Raman, XRD, FE-SEM, EDX, VSM, and TGA techniques, and the organic product structures were examined by melting point, FT-IR and ¹H NMR analyses.

Green synthesis and characterization of novel 1,2,4,5-tetrasubstituted imidazole derivatives with eco-friendly red brick clay as efficacious catalyst

Use of cheaper and recyclable materials contributes positively to economic growth with environmental sustainability. We report the prospect of utilizing red brick clay as catalyst, which exhibited excellent activity in rapid one-pot four-component condensation of 1,2,4,5-tetrasubstituted imidazoles with high conversion and yields (91-96%) in aqueous medium at 60 °C in short reaction times (25-40 min). The red brick clay material was fully characterized by XRD, FT-IR, SEM, TEM, EDX and BET analyses. Red brick clay consisted of oxides of Si (20.38%), Fe (19.55%), Al (14.30%) and minor amounts of Ca (3.60%) and Mg (1.68%). The slate-like-shaped structure morphology and flaky appearance of inexpensive solid clay material proved competent material for the synthesis of 15 novel 1,2,4,5-tetrasubstituted imidazole derivatives. In addition, the advantages of the eco-friendly method are non-toxicity and re-usability of the catalyst. Reaction offers 78% atom economy and 84% carbon capture.