Magnetic catalyst bodies1Netherlands institute for Research in Catalysis (NIOK) publication #UU 98-1-06.1

Sulfamic acid heterogenized on functionalized magnetic Fe3O4 nanoparticles with diaminoglyoxime as a green, efficient and reusable catalyst for one‐pot synthesis of substituted pyrroles in aqueous phase

“…Ultimately, the reaction of amino groups with chlorosulfonic acid leads to MNPs/DAG-SO 3 [33,34] The broad bands at 3170 and 3450 cm À1 are assigned to the N-H and O-H stretching vibrations and the band at 1440 cm À1 is assigned to the C¼N stretching vibration. [35] Reaction of MNPs/DAG with chlorosulfonic acid produces MNPs/DAG- Transmission electron microscopy (TEM) images provide more accurate information on the particle size and morphology of MNPs and Fe 3 O 4 /DAG-SO 3 H (Fig.…”

“…Coating the catalyst surface with an organic or an inorganic shell is an appropriate strategy for preventing this agglomeration. [3][4][5][6][7] The immobilization of homogeneous catalysts on solid supports opens up new avenues for design and engineering of new and interesting catalysts. These structures are easily separable from the reaction mixture, allowing the recovery of the solid and eventually its reuse.…”

“…[22] One of the most common approaches to pyrrole synthesis is the Paal-Knorr reaction in which 1,4-dicarbonyl compounds are converted to pyrroles in the presence of primary amines. Many catalysts have been used for this conversion, such as montmorillonite, KSF clay, [23] microwave irradiation, [24,25] Bi(NO 3 ) 3 Á5H 2 O, [26] Sc(OTf) 3 , [27] TolSO 3 H, [28] layered zirconium phosphate and zirconium sulfophenylphosphonate, [29] titanium, [30] TiCl 4 /Et 3 N [31] and silica sulfuric acid. [32] Although these protocols represent considerable progress, recovery and reuse of catalysts are difficult.…”

コロイド状および担持ナノ粒子の設計─その合成，構造解析と触媒作用─

“…Silica Spherical Nanocatalyst It is widely accepted that the activity of a solid catalyst suspended in a liquid phase can benefit greatly from the use of smaller catalyst particles ( 1 μm) to avoid mass-transfer limitations 57) . However, the difficulties in recovering small particles from the reaction mixture severely circumvent their industrial applications, which can lead to blocking of filters and valves in chemical plants.…”

Fe3O4@SiO2–NH2core-shell nanocomposite as an efficient and green catalyst for the multi-component synthesis of highly substituted chromeno[2,3-b]pyridines in aqueous ethanol media

“…Because of the vast range of the properties, one of the main challenges is the miniaturization of this system to design and construct the novel metal organic nanoparticles. Magnetite nanoparticles have been immobilized on different catalyst supports, including polymers, carbons, and silicas because of easily retrievable and reusable heterogeneous catalyst they are still in high demand, and a striking typicality of supported iron oxide nanoparticles catalyst is that they can be readily separated using an external magnet, which achieves a simple separation of catalyst without filtration (7)(8)(9)(10)(11). Furthermore, they do not only show high catalytic activities but also a high degree of chemical consistency and they do not swell in organic solvents.…”