Synthesis and Characterization of a Polyoxotungstate-Based Magnetic Composite MOF Catalyst for Efficient A3 Coupling Reactions

This research investigates the development and implementation of 11-tungstocupro (II)-silicate incorporated into a magnetic metal–organic framework (MOF) Fe₃O₄/MIL-101(Cr) to serve as a catalyst. For this purpose, the catalyst Fe₃O₄/MIL-101(Cr)@POM underwent synthesis through the co-precipitation procedure, and its structure was perfectly confirmed by various techniques such as FT-IR, XRD, FE-SEM/EDX, and ICP-OES. Following that, during tests of a three-component reaction that combines amine and alkyne compounds with an aldehyde under the A³ coupling reaction, the as-catalyst demonstrated an effectiveness profile, with the reaction conditions optimized to achieve 68.4% efficiency through a 24-h chloroform reflux procedure, whereas the solvent-free reaction route attained 64.5% efficiency, finishing in only 18 h. The reusable catalyst endured minimal degradation in activity while undergoing five cycles. Furthermore, the leaching test detected no leakage in Cu metal concentration for the filtrated solution after the catalytic reaction. This study could properly resolve solubility obstacles and separation limitations that typically restrict homogeneous polyoxometalate catalysts by incorporating polyoxotungstate into the magnetic MOF structure while developing an effective practical solution for field implementations.