Magnetized inorganic-bioorganic nanohybrid [nano Fe3O4-SiO2@Glu-Cu (II)]: A novel nanostructure for the efficient solvent-free synthesis of thiazolidin-2-imines

In this research, a solvent-free four-component one-pot reaction of phenyl isothiocyanate, phenylacetylene, various kinds of aldehydes, and amines was interpreted to obtain the desired five-membered heterocycles named thiazolidin-2-imines. The promotor of this transformation is a novel magnetite-based multilayered inorganic-bioorganic nanohybrid prepared via embedding glutamic acid on the magnetized silica followed by anchoring Cu (II) [nano Fe3O4-SiO2@Glu-Cu (II)]. The newly synthesized nanostructure is characterized through Fourier-transform infrared (FT-IR), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDAX), transmission electron microscopy (TEM), X-ray fluorescence (XRF), thermogravimetric analysis or derivative thermogravimetric (TGA/DTG), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) techniques. This protocol is a straightforward one-step procedure to obtain thiazolidin-2-imines without requirement to propargylamines or imines as substrates. In addition, easy work-up procedure, high yields of products, absence of organic solvents in the reaction media, recovery and reusability of nano Fe3O4-SiO2@Glu-Cu(II) to promote the reaction at least for three runs without activity lost, simple separation of the catalyst from reaction mixture via an external magnet, and regioselectivity of the method are some highlighted aspects of the approach.

Automated summary

This research demonstrates a solvent-free four-component one-pot reaction to obtain thiazolidin-2-imines using a novel magnetite-based multilayered inorganic-bioorganic nanohybrid. The synthesized nanostructure was characterized using various techniques, and the approach showed high yields, simple work-up procedure, and excellent reusability of the catalytic material.