Magnetic nanocomposite of crosslinked chitosan with 4,6-diacetylresorcinol for gold immobilization (Fe3O4@CS/DAR-Au) as a catalyst for an efficient one-pot synthesis of propargylamine

Abstract

The magnetic DAR-chitosan was synthesized by condensation of magnetic chitosan [Fe3O4@CS] with freshly synthesized diacetylresorcinol (here calls DAR) as a cross-linking agent; the Schiff base precursor on the as-prepared magnetic DAR-chitosan polymer can be coordinated with Au (III) to give magnetic DAR chitosan-based Au (III) Schiff base complex (Fe3O4@CS/DAR-AuCl3). The structural properties of Fe3O4@CS/DAR-AuCl3 have been investigated by SEM, TEM, EDX, XRD, FT-IR and XPS (techniques) analysis. The XPS study proved the presence of Au species Schiff base complex as an ion and nanoparticles onto the magnetic DAR crosslinked chitosan. Subsequently, the synthesized Fe3O4@CS/DAR-AuCl3 used as sustainable catalysts in A3 coupling reactions leading to the synthesis of propargylamine, a pharmaceutical building blocks, under mild conditions in high yields of 80–92%. Furthermore, it was proved that the magnetic Fe3O4@CS/DAR-AuCl3 was easily recovered and reached 76% of the initial activity after 8 times, which revealed good reuse capacity.