Magnetic catalyst marvels: a sustainable approach to highly substituted imidazole synthesis

Abstract

This comprehensive review delves into the recent advancements in magnetic catalyst technology, mainly focusing on their application in facilitating greener and more efficient synthetic routes for imidazole derivatives. This manuscript assesses various magnetic catalyst systems, examining their synthesis, functionalization, and mechanistic roles in promoting imidazole formation. Special attention is given to the environmental benefits of using magnetic catalysts, such as reduced solvent use, lower energy consumption, and enhanced recyclability, which align with sustainable chemistry principles. The unique properties of magnetic catalysts, including their easy recovery via external magnetic fields and reusability without significant loss of activity, are highlighted as key factors driving the synthetic processes' sustainability and economic viability. Furthermore, the review discusses the challenges and limitations currently faced in this realm and proposes future directions for research, including the development of novel magnetic catalyst compositions and the exploration of their utility in other heterocyclic syntheses. By providing a detailed analysis of existing data and suggesting pathways for innovation, this review aims to inspire continued advancement in sustainable catalysis, promising to revolutionize the synthesis of highly substituted imidazoles and expand their potential applications in various industries. This manuscript is a crucial resource for researchers in catalysis and sustainable chemistry. It underscores the broader implications of magnetic catalysts in enhancing green manufacturing practices in the chemical industry, thereby contributing to global sustainability goals.

Fig. 1. Advantageous of an ideal catalyst.

Fig. 2. Advantages of Magnetically Recoverable Catalysts (MRCs).

Fig. 3. Advantages and disadvantages of homogeneous and heterogeneous catalysts.

Fig. 4. Magnetically recoverable catalysts (MRCs) as a bridge between homogeneous and heterogeneous catalysts.

Fig. 5. Biological and pharmacological activities of highly substituted imidazole derivatives.

Fig. 6. Several drugs and bioactive molecules containing a highly substituted imidazole scaffold.

Scheme 1. Synthesis of 1,2,4,5-tetrasubstitutedimidazoles [catalysis by CuFe₂O₄ NPs].

Scheme 2. Plausible mechanism for synthesis of 1,2,4,5-tetrasubstitutedimidazoles [catalysis by CuFe₂O₄ NPs].

Scheme 3. Synthesis of triaryl imidazoles [catalysis by Fe₃O₄ NPs].

Scheme 4. Synthesis of triaryl imidazoles [catalysis by Ni_0.5Zn_0.5Fe₂O₄ NPs].

Scheme 5. Plausible mechanism for synthesis of triaryl imidazoles [catalysis by Ni_0.5Zn_0.5Fe₂O₄ NPs].

Scheme 6. Synthesis of triaryl imidazoles [catalysis by MnFe₂O₃ nanoparticles].

Scheme 7. Synthesis of triaryl imidazoles [catalysis by the MNPs-SiO₂-urea nanocomposite].

Scheme 8. Synthesis of triaryl imidazoles [catalysis by the [P₄-VP]-Fe₃O₄ nanocomposite].

Scheme 9. Plausible mechanism for synthesis of triaryl imidazoles [catalysis by the [P₄-VP]-Fe₃O₄ nanocomposite].

Scheme 10. Synthesis of triaryl imidazoles [catalysis by Fe₃O₄-FU NPs].

Scheme 11. Synthesis of 1,2,4,5-tetrasubstituted imidazoles [catalysis by Fe₃O₄-FU NPs].

Scheme 12. Synthesis of triaryl imidazoles [catalysis by the FeCeO_x@g-C₃N₄ nanomaterial].

Scheme 13. Synthesis of 1,2,4,5-tetrasubstituted imidazoles [catalysis by the FeCeO_x@g-C₃N₄ nanomaterial].

Scheme 14. Synthesis of triaryl imidazoles [catalysis by the H₃PW₁₂O₄₀-amino-functionalized CdFe₁₂O₁₉@SiO₂ nanomaterial].

Scheme 15. Synthesis of triaryl imidazoles [catalysis by the Fe₃O₄@CS nanocomposite].

Scheme 16. Synthesis of 1,2,4,5-tetrasubstitutedimidazoles [catalysis by the Fe₃O₄@SiO₂-EPIM nanocomposite].

Scheme 17. Plausible mechanism for synthesis of 1,2,4,5-tetrasubstitutedimidazoles [catalysis by the Fe₃O₄@SiO₂-EPIM nanocomposite (MRC-11)].

Scheme 18. Synthesis of 1,2,4,5-tetrasubstituted imidazoles [catalysis by the IL-Fe₃O₄ MNPs nanomaterial].

Scheme 19. Synthesis of triaryl imidazoles [catalysis by the Fe₃O₄@SiO₂-imid-PMAⁿ nanocomposite].

Scheme 20. Synthesis of 1,2,4,5-tetrasubstituted imidazoles [catalysis by the Fe₃O₄@SiO₂-imid-PMAⁿ nanocomposite].

Scheme 21. Plausible mechanism for synthesis of 1,2,4,5-tetrasubstituted imidazoles [catalysis by the Fe₃O₄@SiO₂-imid-PMAⁿ nanocomposite].

Scheme 22. Synthesis of triaryl imidazoles [catalysis by the γ-Fe₂O₃-SO₃H nanocomposite].

Scheme 23. Synthesis of 1,2,4,5-tetrasubstitutedimidazoles [catalysis by the γ-Fe₂O₃-SO₃H nanocomposite].

Scheme 24. Plausible mechanism for synthesis of triaryl imidazoles [catalysis by the γ-Fe₂O₃-SO₃H nanocomposite].

Scheme 25. Synthesis of triaryl imidazoles [catalysis by the SiO₂/Fe₃O₄/SO₃H nanocomposite].

Scheme 26. Synthesis of 1,2,4,5-tetrasubstituted imidazoles [catalysis by the MPBNP nanocomposite].

Scheme 27. Synthesis of triaryl imidazoles [catalysis by the SA-MNP nanocomposite].

Scheme 28. Synthesis of triaryl imidazoles [catalysis by the Fe₃O₄-diamine-CuI nanocomposite].

Scheme 29. Plausible mechanism for synthesis of triaryl imidazoles [catalysis by the Fe₃O₄-diamine-CuI nanocomposite (MRC-18)].

Scheme 30. Synthesis of triaryl imidazoles [catalysis by the Fe₃O₄-PEG-Cu nanomaterial].

Scheme 31. Synthesis of 1,2,4,5-tetrasubstituted imidazoles [catalysis by the Fe₃O₄-PEG-Cu nanomaterial (MCR-19)].

Scheme 32. Synthesis of 1,2,4,5-tetrasubstituted imidazoles [catalysis by the Cu₂O/Fe₃O₄@guarana nanomaterial].

Scheme 33. Synthesis of triaryl imidazoles [catalysis by the Cu₂O/Fe₃O₄@guarana nanomaterial (MRC-20)].

Scheme 34. Synthesis of triaryl imidazoles using benzil as the substrate [catalysis by the Cu/GA/Fe₃O₄@SiO₂ nanocomposite].

Scheme 35. Synthesis of triaryl imidazoles using 2-hydroxy-1,2-diphenylethan-1-one as the substrate [catalysis by the Cu/GA/Fe₃O₄@SiO₂ nanocomposite].

Scheme 36. Synthesis of triaryl imidazoles [catalysis by the ZnS-CuFe₂O₄ nanomaterial].

Scheme 37. Synthesis of triaryl imidazoles [catalysis by the LADES@MNP nanomaterial].

Scheme 38. Synthesis of 1,2,4,5-tetrasubstituted imidazoles [catalysis by the LADES@MNP nanomaterial].

Scheme 39. Synthesis of triaryl imidazoles from benzil [catalysis by the cellulose/γ-Fe₂O₃/Ag nanocomposite (MRC-24)].

Scheme 40. Synthesis of triaryl imidazoles from benzil [catalysis by the cellulose/γ-Fe₂O₃/Ag nanocomposite (MRC-24)].

Mosstafa Kazemi

Ramin Javahershenas