Preparation Of Magnetic Nanoparticles Supported Task-specific Ionic Liquids And Its Applications In Organic Synthesis

As a new type of green catalytic technology, ionic liquid catalytic has beenwidely applied in organic synthesis in recent years. At the same time, magneticnanoparticles supported catalyst shows incomparable catalytic activity in organicsynthesis that many traditional catalysts can’t compare with. It’s a new nanometercatalyst, integrating magnetic recycling and high catalytic activity. Combined with thecharacteristics of ionic liquids and magnetic nanoparticles, in this paper, we designedand synthesized two types of functional ionic liquids and load it onto the magneticnanoparticles. Through some important Michael addition reaction or Knoevenagelcondensation reaction, we also explore the performance and applicability of thesesupported catalysts.First, we designed and synthesized two magnetic nanoparticles supported ionicliquids. The properties and structure of these magnetic supported catalysts have beencharacterized by X-ray diffraction (XRD), transmission electron microscopy (TEM),magnetic testing, and thermogravimetric analysis. All these characterization methodsensure the success of the ionic liquids supported onto magnetic nanoparticles.Secondly, the magnetic nanoparticles supported ionic liquid IT-DABCO@MNP,was used in the Michael addition of amine with, β-unsaturated amide. Through aseries of reaction conditions optimization, it was found that at room temperature, withwater as reaction solvent, using1.0mol%catalyst amount of IT-DABCO@MNP, thecatalysis effect is best. The catalyst IT-DABCO@MNP has excellent catalyticperformance, affording the desired products in good yields (70%-93%). At thesame time, the catalyst has good recyclability and reused for the same reactionwithout obvious loss of activity.Finally, we studied the Knoevenagel condensation reactions of complex activemethylene compounds with aromatic aldehyde and the Michael addition of various,β-unsaturated malonates with diethyl phosphate. All the reactions were catalyzed byPA-IL@MNP. The results show that the supported catalyst has excellent catalyticperformance, has wide application scope, and can be reused for many times. We alsopresented possible reaction mechanisms in the two types of reactions. Above all, the two kinds of magnetic nanoparticles supported ionic liquids haveefficient catalytic activity, and can be well applied to the Michael addition andKnoevenagel condensation reactions. The magnetic nanoparticles supported ionicliquids show quicker reaction rate, higher product yields and reusable features whencompared with the traditional catalyst. The catalysts are expected to get a wider rangeof application in future research.