Magnetic Nanoparticles as an Orthogonal Support of Polymer Resins: Applications to Solid-Phase Suzuki Cross-Coupling Reactions

Synthesis of nano magnetic supported NHC-palladium and investigation of its applications as a catalyst in the Mizoroki-Heck cross-coupling reaction in H2O

The unique properties of N-heterocyclic carbenes (NHCs) as an effective ligand for palladium catalytic centers have recently found much attention. In this work, Fe₃O₄ nanoparticle supported palladium(II)-N-heterocyclic carbene catalyst was successfully designed, synthesized and characterized by various methods. The activity of the catalyst was evaluated in the Mizoroki-Heck cross-coupling reaction in which the desired products were obtained in high yield in H₂O as a green solvent. The reaction was carried out in short reaction times using low amounts of the catalyst. Moreover, the catalyst was easily separated from the reaction media and reused for 5 cycles.

Cu(ii) immobilized on Fe3O4@APTMS-DFX nanoparticles: an efficient catalyst for the synthesis of 5-substituted 1H-tetrazoles with cytotoxic activity

Cu(ii) immobilized on deferasirox loaded amine functionalized magnetic nanoparticles (Cu(ii)/Fe₃O₄@APTMS-DFX) as a novel magnetically recyclable heterogeneous catalyst is able to catalyze the [3 + 2] cycloaddition reactions of various organic nitriles with sodium azide. Using this method, a series of 5-substituted-1H-tetrazoles under mild conditions in DMSO were prepared. The reaction involves mild reaction conditions with efficient transformation capability. The developed catalyst could be easily separated by applying an external magnetic field. Furthermore, it could be recycled for 5 runs with negligible leaching of copper from the surface of the catalyst. The catalyst was characterized by various techniques such as FT-IR, TGA, VSM, SEM-EDX, and ICP-OES. Several derivatives of 1H-tetrazoles were prepared using this catalyst, and their structures were confirmed using different techniques. Then, the synthesized anthraquinones were evaluated for their cytotoxicity against several cell lines including MCF-7, MAD-MD-231, HT-29, HeLa, neuro-2a and L-929. The results obtained from the MTT assay revealed that the 6 derivatives exhibited a high level of cytotoxicity. In order to determine the cytotoxicity mechanism, 2 derivatives with the highest cytotoxic activity were selected, and an apoptosis assay was carried out by flow cytometry, which supported that apoptosis is the major mechanism.

Cu–EDTA-modified APTMS-Fe3O4@SiO2 core–shell nanocatalyst: a novel magnetic recoverable catalyst for the Biginelli reaction

A novel copper–ethylenediamine tetracarboxylate modified core–shell magnetic catalyst is introduced.

Magnetically recoverable catalysts based on mono- or bis-(NHC) complexes of palladium for the Suzuki–Miyaura reaction in aqueous media: two NHC–Pd linkages are better than one

Mono- and bis(NHC) Pd complexes grafted onto magnetic particles are compared as catalysts in the Suzuki–Miyaura reaction in aqueous media. The latter is found to be an outstanding recyclable catalyst.

Spherical core-shell magnetic particles constructed by main-chain palladium N-heterocyclic carbenes

The encapsulation of the functional species on magnetic core is a facile approach for the synthesis of core-shell magnetic materials, and surface encapsulating matrices play crucial roles in regulating their properties and applications. In this study, two core-shell palladium N-heterocyclic carbene (NHC) particles (Fe3O4@PNP1 and Fe3O4@PNP2) were prepared by a one-pot reaction of semi-rigid tripodal imidazolium salts and palladium acetate in the presence of magnetite nanoparticles. The magnetite nanoparticles are encapsulated inside the main-chain palladium, which act as cores. The conjugated effects of triphenyltriazine and triphenylbenzene in the imidazolium salts have important influence on their physical properties and catalytic performances. Fe3O4@PNP2 shows better recyclability than Fe3O4@PNP1. Unexpectedly, Pd(ii) is well maintained after six consecutive catalytic runs in Fe3O4@PNP2, and Pd(0) and Pd(ii) coexist in Fe3O4@PNP1 under the same conditions; moreover, the morphologies of these spherical core-shell particles show no significant variation after six consecutive catalytic runs.

1-Methyl-3-(propyl-3-sulfonic acid)imidazolium triflate supported on magnetic nanoparticles: an efficient and reusable catalyst for synthesis of mono- and bis-isobenzofuran-1(3H)-ones under solvent-free conditions

An efficient procedure for the synthesis of isobenzofuran-1(3H)-one derivatives in the presence of [HSO₃PMIM]OTf–SiO₂@MNPs as a highly recyclable catalyst under solvent-free thermal conditions and MW irradiation is reported.

Preparation of naphthyl functionalized magnetic nanoparticles for extraction of polycyclic aromatic hydrocarbons from river waters

Naphthyl functionalized magnetic nanoparticles (Fe₃O₄@SiO₂@Nap) was prepared and successfully applied for the magnetic solid-phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) from river water samples.

Design and synthesis of a new phosphinite-functionalized clay composite for the stabilization of palladium nanoparticles. Application as a recoverable catalyst for C–C bond formation reactions

Pd-catalyzed C–C bond formation in green media, combining the advantages of homogeneous IL phase, phosphorylated ligands and a new heterogeneous clay support.

Magnetic nanocatalyst for the synthesis of maleimide and phthalimide derivatives

An efficient and green protocol for the synthesis of N-aryl maleimide and phthalimide derivatives has been developed.

Batchwise and continuous nanofiltration of POSS-tagged Grubbs-Hoveyda-type olefin metathesis catalysts

New molecular-weight-enlarged metathesis catalysts, which bear polyhedral oligomeric silsesquioxane (POSS) tags, were synthesized and characterized. The catalysts can be recovered from the reaction mixture by using nanofiltration techniques and can be reused. It was found that the membranes Starmem 228 and PuraMem 280 successfully separate the catalyst from the post-reaction mixtures to below 3 ppm. The application of these POSS-tagged catalysts in a continuous metathesis reaction was also investigated.