Application of supported palladium nanoparticles over chitosan-agarose encapsulated Fe3O4 microspheres as efficient catalyst in the Sonogashira cross-coupling reactions

Abstract

In this work, a simple and modified method for immobilizing Pd(0) NPs on the surface of dual functionalized magnetic Fe₃O₄ microspheres with chitosan-agarose (CS-Agar) has been used. The high area surface showed a dispersion of the minuscule Pd NPs. The key role of the CS-Agar hydrogel is to reduce Pd ions via a green pathway, stabilizing them via capping in the process. In order to determine the morphological aspects of the synthesized material, it was subjected to a variety of physicochemical techniques, including FE-SEM (Field Emission Scanning Electron Microscopy) and TEM (Transmission Electron Microscopy). The new material was studied catalytically as a reusable heterogeneous nanocatalyst that is effective in phosphine-free production of a variety of stilbene derivatives using the Sonogashira coupling method. Excellent results were obtained in every reaction, with the exception of chloroarenes and sterically hindered substrates. Without seeing a discernible decline in activity, the catalyst was reused seven times in a row.