Preparation, characterizations, and application of (MWCNTs)-COOH/Fe3O4-CaO hybrid as an effective magnetic catalyst for direct C-glycosylation reactions.

Modification of acid-functionalized multiwalled carbon nanotubes (MWCNTs)-COOH with Fe₃O₄-CaO nanoparticles using FeSO₄ and eggshell, produced an efficient magnetic catalyst for the synthesis of some C-glycosides. The condensation of dimedone with unprotected sugars in ethanol in the presence of a catalytic amount of (MWCNTs)-COOH/Fe₃O₄-CaO gave 3,4,5,6,7,9-hexahydro-1H-xanthene-1,8 (2H)-dione derivatives in good yields. The products were identified by CHN analysis, NMR, and FTIR spectra. Conversely, synthesis of Fe₃O₄-CaO nanoparticles and their conjugation on the surface of (MWCNTs)-COOH have been confirmed by FTIR, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. [ABSTRACT FROM AUTHOR]