超顺磁性纳米颗粒及其复合材料作为有机反应的催化剂,不仅能通过外加磁场实现催化剂的分离回收,且在反应介质中催化活性位点利用率高,可起到均相催化的效果。本文在系统总结近年来磁性纳米催化剂制备的基础上,阐述了磁性纳米催化剂的制备方法、结构类型和特点。同时,对催化剂在有机合成中的应用和催化效果进行了综述,对磁性纳米催化剂在反应中失活的原因做了详尽分析,展望了超顺磁性纳米颗粒的主要发展方向和今后仍需解决的问题。
Superparamagnetic nanoparticles and composite materials, which are highly active, possessing high surface to volume ratios and having high surface energies, can be used as catalysts. Since the small particle size of magnetic nanoparticles, the nano-heterogeneous catalysts can achieve similar or even higher activities compared with the homogeneous catalysts. Moreover, they can be reused after separation from the reaction system by using a magnet and simple regeneration process. The application of magnetic nano-catalysts in organic synthesis has attracted wide attention. Here, we review the preparation and application in organic synthesis of the magnetic nano- catalysts. The preparations, structures and characteristics of magnetic nano-catalysts are summarized. We also present their catalytic effect in relevant organic synthesis and analyze the deactivation of magnetic nano-catalysts in detail. Finally, the remaining problems and the future developing prospects are proposed.