Magnetic horsetail plant ash (Fe3O4@HA): a novel, natural and highly efficient heterogeneous nanocatalyst for the green synthesis of 2,4,5-trisubstituted imidazoles

• Published in: Research on chemical intermediates 2021-06, Vol.47 (6), p.2507-2525
• Main Authors: Hosseini Mohtasham, Nina, Gholizadeh, Mostafa
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Ashes; Catalysis; Catalytic activity; Chemical synthesis; Chemistry; Chemistry and Materials Science; High temperature; Imidazole; Inorganic Chemistry; Iron oxides; Morphology; Nanoparticles; Physical Chemistry; Room temperature; Silicon dioxide
• ISSN: 0922-6168; 1568-5675
• DOI: 10.1007/s11164-021-04420-y

Horsetail plant ash (HA), as a natural source of mesoporous silica, has been prepared from the exposure of horsetail plant (Equisetum Arvense) to high temperature. In the present study, a new magnetically separable and also recoverable Fe 3 O 4 nanoparticles were synthesized in the presence of natural horsetail plant ash (HA) as a support to result in Fe 3 O 4 @HA. FT-IR, XRD, TEM, SEM–EDX and VSM analysis were combined to characterize the morphology and structure of this novel synthesized nanocatalyst. This magnetically solid acid nanocatalyst showed an excellent catalytic activity for the synthesis of 2,4,5-trisubstituted imidazoles at room temperature in aqueous media. The procedure led to corresponding products in high to excellent yields and appropriate times. Additionally, this nanocatalyst can be easily recovered by a magnetic field and reused for six other consecutive reaction runs without noticeable loss of its catalytic efficiency. Based on this study, Fe 3 O 4 @HA is found to be an efficient, magnetically separable, recyclable, and green catalyst with natural source. Graphic abstract In this work, horsetail plant ash was used as a natural source of mesoporous silica for the synthesis of Fe 3 O 4 @HA as a highly powerful magnetically solid acid nanocatalyst, which was fully characterized using various techniques. The activity of the newly synthesized nanocatalyst was tested for the synthesis of 2,4,5-trisubstituted imidazole derivatives.