Novel Inorganic-Bioorganic Functionalized Silica-Magnetized Core-Shell (Nano SO₃H-D-Leu@SiO₂-Fe₃O₄) as Reusable Promoter for the Synthesis of 7,7'-((Aryl)Methylene)Bis(N-Cyclohexyl-2-(Aryl)-6-Methyl-3H-Imidazo[1,2-b]Pyrazol-3-Imine) Derivatives

Abstract

In this research, a new bio multilayered nanostructure based on commercial nanomagnetite has been prepared. Gradually the silica and D-leucine amino acid, as the bio part, anchored on the surface of nano Fe₃O₄ followed by functionalization step, accomplished with chlorosulfonic acid. This bio-nano organic–inorganic core-shell hybrid (nano SO₃H-D-Leu@SiO₂-Fe₃O₄₎ characterized by FESEM, EDAX, FT-IR, TGA/DTG, TEM, VSM, and XRF techniques. Its efficient catalytic activity examined for the synthesis of 7,7'-((aryl/alkyl)methylene)bis(N-cyclohexyl-2-(aryl/alkyl)-6-methyl-3H-imidazo[1,2-b]pyrazol-3-imine) derivatives through a pseudo-seven component one-pot and one-step reaction of various aldehydes, 3-amino-5-methylpyrazole, and cyclohexyl isocyanide in ethanol solvent at room temperature with excellent yields. The condensed products obtained via construction of various new C-C and C = N bonds. The interpreted protocol included advantages, such as easy preparation approach for nano-sized bio core-shell organic–inorganic hybrid, short reaction times, simple work-up process due to separation of the catalyst by an external magnet, recovery, and reusability of the nanocatalyst for three runs without notable activity loss (the recovered nanostructure characterized by FESEM and EDAX techniques), utilizing different class of aldehydes successfully, and regioselectivity of the procedure.

Keywords:

• Imidazopyrazol imine
• isocyanide
• magnetite
• multicomponent reaction
• nano SO₃H-D-Leu@SiO₂-Fe₃O₄

Disclosure statement

There are no conflicts of interest.

Additional information

Funding

The authors thank to Alzahra University Research Council for support of this work.