Synthesis, Characterization, and Catalytic Properties of Magnetic Fe3O4@FU: A Heterogeneous Nanostructured Mesoporous Bio-Based Catalyst for the Synthesis of Imidazole Derivatives.

Maryam Banazadeh,Sara Amirnejat,Shahrzad Javanshir

doi:10.3389/fchem.2020.596029

Maryam Banazadeh, Sara Amirnejat + Show 1 more

Open Access

https://doi.org/10.3389/fchem.2020.596029

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Abstract

In this protocol, Fucoidan (FU), a fucose-rich sulfated polysaccharide extracted from brown algae Fucus vesiculosus was used for in situ preparation of magnetic Fe3O4@FU. Nanoco magnetic properties of Fe3O4@FU were investigated by energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) adsorption method, and vibrating sample magnetometer (VSM). The catalytic activity of Fe3O4@FU was employed for the synthesis of tri- and tetra-substituted imidazoles through three- and four-component reactions respectively, between benzyl, aldehydes, NH4OAc and benzyl, aldehydes, NH4OAc, and amine under reflux in ethanol. It is worth nothing that excellent yields, short reaction times, chromatography-free purification, and environmental friendliness are highlighted features of this protocol.

Highlights

Through extensive applications and potential in the chemical industry and preservation of the environment, the recently supported solid nanocatalysis has been faced with various attentions in catalysis science and technology (Amirnejat et al, 2013; Fereshteh and Shahrzad, 2020)
Numerous approaches have been developed for the synthesis of 1,2,4,5-tetrasubstituted imidazoles, which can be prepared by a four-component cyclo condensation consisting of aldehyde, benzil, a primary amine and ammonium acetate in the presence of different catalysts such as BF3·SiO2 (Sadeghi et al, 2008), and silica gel/NaHSO4 (Karimi et al, 2006), while other main components are achieved by synthesis of tri-substituted imidazoles by the condensation of benzil derivatives, aryl aldehydes, and ammonium acetate catalyzed by different catalysts such as ZrCl4 (Shitole et al, 2015), sulfanilic acid (Gadekar et al, 2009), and chitosan (Zheng et al, 2019)
Fe3O4@FU magnetic nanoparticles as a heterogeneous catalyst were characterized by Fourier transform infrared (FT-IR) spectral analysis

Summary

INTRODUCTION

Through extensive applications and potential in the chemical industry and preservation of the environment, the recently supported solid nanocatalysis has been faced with various attentions in catalysis science and technology (Amirnejat et al, 2013; Fereshteh and Shahrzad, 2020). Numerous approaches have been developed for the synthesis of 1,2,4,5-tetrasubstituted imidazoles, which can be prepared by a four-component cyclo condensation consisting of aldehyde, benzil, a primary amine and ammonium acetate in the presence of different catalysts such as BF3·SiO2 (Sadeghi et al, 2008), and silica gel/NaHSO4 (Karimi et al, 2006), while other main components are achieved by synthesis of tri-substituted imidazoles by the condensation of benzil derivatives, aryl aldehydes, and ammonium acetate catalyzed by different catalysts such as ZrCl4 (Shitole et al, 2015), sulfanilic acid (Gadekar et al, 2009), and chitosan (Zheng et al, 2019) Some of these methodologies have some drawbacks, such as low yields, long reaction times, severe reaction conditions, and work up procedure. Easy work up and separation, high product yields and short reaction times made this method effective and advantageous

Materials and Methods

RESULTS AND DISCUSSION

CONCLUSION

DATA AVAILABILITY STATEMENT