Magnetically recoverable nanoparticles as efficient catalysts for organic transformations in aqueous medium
Development of magnetic nanoparticles (MNPs) for use as supports and exploration of their applications in aqueous catalysis represent an important branch of green chemistry as they enable environmentally friendly and sustainable catalytic processes. Besides the significant merit of easily recovering magnetic nanoparticles from reaction systems, various strategies through surface modification, grafting and self-assembly offer a broad range of approaches for constructing magnetically recoverable heterogeneous catalysts. In this review, we focus on the green catalytic processes and summarize recent advances in organic transformations catalyzed by magnetically recoverable catalysts (MRCs). This paper is divided into two main parts: the first part provides background information on the general preparation, modifications, and characterization, where the modifications of various magnetic nanoparticles through coating with silica, carbon, metal, or polymer are also presented. The second part provides a basic outline of aqueous catalysis based on water-only or water-and-organic solvent cosolvent systems, in which numerous types of organic transformations are catalyzed by magnetically recoverable catalysts. Lastly, perspectives for further development of magnetically recoverable heterogeneous catalysts in aqueous catalysis are addressed.