Solvent-Free Synthesis of 1,2,4,5-Tetrasubstituted Imidazoles Using Nano Fe3O4@SiO2-OSO3H as a Stable and Magnetically Recyclable Heterogeneous Catalyst

Abstract

Nano-Fe 3 O 4 encapsulated-silica particles bearing sulfonic acid groups (Fe 3 O 4 @SiO 2 -OSO 3 H) has been used as an efficient and magnetically separable heterogeneous catalyst for the synthesis of 1,2,4,5-tetrasubstituted imidazoles by one-pot, four-component reaction of benzil, aromatic aldehydes, primary amines, and ammonium acetate under neat conditions. The effect of various reaction parameters, such as reaction temperature, catalyst loading and solvent effect, were studied. The desired products are obtained in relatively short reaction times with high yields. Importantly, the catalyst could be easily separated from the reaction mixture by a permanent magnet and reused for several times without the significant loss of its activity.

Metal‐based nanoparticles for bone tissue engineering

“…One of the most significant features of iron oxide nanoparticles is their catalytic activity in multicomponent reactions (Eivazzadeh‐Keihan, Radinekiyan, Maleki, Bani, & Azizi, 2020). Examples of iron oxide based NP composites include, Fe 3 O 4 @cellulose composite (Maleki & Kamalzare, 2014), chitosan supported Fe 3 O 4 nanoparticles (Rahimi, Safa, & Salehi, 2017, Rahimi, Shafiei‐Irannejad, Safa, & Salehi, 2018), cellulose‐based magnetic nanocomposite (Rahimi et al, 2017), CoFe 2 O 4 @B 2 O 3 ‐SiO 2 magnetic composite (Maleki, Aghaei, Hafizi‐Atabak, & Ferdowsi, 2017), cellulose/Fe 2 O 3 /Ag bionanostructure (Maleki, Ravaghi, & Movahed, 2018), Fe 3 O 4 /SiO 2 ‐OSO 3 H nanostructure (Yadegarian, Davoodnia, & Nakhaei, 2015), and magnetic cellulose/Ag nanobiocomposite (Maleki et al, 2017). Besides their catalytic activity, magnetic nanoparticles can be utilized in drug delivery by the application of eternal magnetic fields (Rahimi et al, 2018, Rahimi et al, 2019).…”

One‐Pot Multicomponent Synthesis of Pyrrolo[1,2‐a]pyrazines in Water Catalyzed by Fe3O4@SiO2‐OSO3H

“…Fe 3 O 4 @SiO 2 ‐OSO 3 H used for the synthesis compounds such as 1,2,4,5‐tetrasubstitutedimidazoles, pyrido[2 / ,1 / :2,3]imidazo[4,5‐c]isoquinolines. 1,4‐Dihydropyridines, Tricarboxamides …”

TiO2‐nanoparticles as efficient catalysts for the synthesis of pyridine dicarbonitriles

“…Among the nitrogen‐containing heterocycles, densely substituted pyridine derivatives are one of the most important classes of compounds as they widely occur as key structural subunits in numerous natural products that exhibit many interesting biological activities . In addition, these heterocyclic compounds have found a variety of applications in medicinal and pharmaceutical sciences . Among these pyridine derivatives, 2‐amino‐6‐(arylthio)pyridine‐3,5‐dicarbonitrile is a privileged scaffold for developing pharmaceutical agents because various compounds with this structural motif display significant and diverse biological activities.…”

“…[1] In addition, these heterocyclic compounds have found a variety of applications in medicinal and pharmaceutical sciences. [2] Among these pyridine derivatives, 2-amino-6-(arylthio)pyridine-3,-5-dicarbonitrile is a privileged scaffold for developing pharmaceutical agents because various compounds with this structural motif display significant and diverse biological activities. For example, adenosine receptors are associated with Parkinson's disease, hypoxia, asthma, epilepsy, cancer, and cardiovascular diseases.…”