Synthesis And Application Of New Magnetic Nanoparticles In Organic Synthesis

In recent years, green chemistry and sustainable chemistry have become major areas ofresearch. Due to nanoparticles(NPs) have high catalytic activity, they have been widely usedin organic reactions. Nanocatalysts could effectively bridge the gap between homogeneousand heterogeneous catalysis thanks to their good dispersion properties, high catalytic activityand selectivity. However, the tedious and costly separation and recovery procedure of thepowdery nanocatalysts make it difficult using in industry-scale applications. To furtheraddress the issues of separation, recovery and recycling of catalysts from the reaction mixture,magnetic nanoparticles(MNPs) have emerged as an ideal support because of their uniqueseparable features by magnetic forces. MNPs as a catalyst in organic synthesis receivedextensive attention by chemists. Those catalysts are environmental-friendly because they canbe recycled. Compared to conventional separation methods (such as: filtering and extraction),separation of magnetic nanomaterials are simpler than them. They can be separated bypermanent magnet outside. After simple washing they can be reused with high activity.We use novel magnetic nano-materials [CoFe2O4@SiO2-PrNH2-PMo] as catalyst,epoxide as raw material, the ether solution of hydrogen peroxide as oxidant, ring-openingreaction of epoxide to give β-hydroxy hydroperoxides (HHPS).[CoFe2O4@SiO2-PrNH2-PMo]as magnetic nano-material is easy to be separated and recycled. Direct construction of theperoxy bond in organic synthesis using hydrogen peroxide has long been one of the mostchallenging research targets. Particularly, the ring-opening reaction of epoxides with H2O2isan important means for preparing HHPs. HHPs can conveniently be converted into thecorresponding1,2,4-trioxanes.Firstly, we prepared aluminium chloride supported on γ-Fe2O3nanoparticle[Al-IL-SiO2@γ-Fe2O3]. Using β-diketone compound and a series of alcohol compound as araw material, the reaction was completed at room temperature, to give the correspondingβ-keto enol ether compound with high yield. The immobilized catalyst proved to be effectiveand provided the products in high yield at room temperature. Moreover, the catalyst could be easily recovered by magnetic separation and recycled for six times without significant loss ofits catalytic activity.Pyrrole derivatives are one of the most important intermediates in organic synthesis,since they constitute the core unit of many natural products, synthetic materials and medicinalchemistry. We first prepared magnetic nanomaterials supported antimony trichloride[γ-Fe2O3@SiO2-Sb-IL]. The reaction was refluxed in aqueous solution, obtainedcorresponding pyrroles with high yield. Magnetic nanomaterials have high catalytic activityfor synthesis of pyrrole compounds with many advantages such as simple, easy separation andrecyclability.