The CuFe₂O₄@SiO₂@ZrO₂/SO₄²⁻/Cu nanoparticles: an efficient magnetically recyclable multifunctional Lewis/Brønsted acid nanocatalyst for the ligand- and Pd-free Sonogashira cross-coupling reaction in water

Abstract

A mild and green protocol was developed by immobilizing copper-incorporated sulfated zirconium oxide on CuFe2O4 as an efficient inorgano-nanocatalyst for the Sonogashira reaction.

Fe3O4@Sap/Cu(ii): an efficient magnetically recoverable green nanocatalyst for the preparation of acridine and quinazoline derivatives in aqueous media at room temperature

“…Scheme 3 shows the possible interaction of the catalyst and the reactants for the condensation reaction of benzaldehyde, aniline and dimedone (preparation of 11a) perfectly in accordance with the literature. 6,18,68 The results were completely consistent with theoretical expectations, wherein the presence of lipophilic aglycone groups in the saponin structure causes the hydrophobic reactants to be directed (diffused) into the catalyst framework and (theoretically), consequently, the active catalytic centers (presence of copper groups) provides proper interaction between the surface of the catalyst and the raw materials causes them to condense and give the desired product (Scheme 3). Due to the insolubility of the product in the aqueous medium, the product is given out from the catalyst medium and acts as a driving force (as seen in Le Chatelier's principle).…”

“…[3][4][5] Hitherto, innovative catalysts have been developed as a fruitful strategy with the aid of natural organic compounds. 3,6,7 Saponins are a diverse group of plant amphipathic glycosides 8 consisting of steroid or triterpenoid aglycone attached to one or more sugar chains. 9 The saponins structure can be seen in many plants; such as Sapindaceae, 10 Panax, 11 Gynostemma, 12 and Hippocastanaceae 13 (Fig.…”

Functionalization of superparamagnetic Fe3O4@SiO2nanoparticles with a Cu(II) binuclear Schiff base complex as an efficient and reusable nanomagnetic catalyst forN‐arylation of α‐amino acids and nitrogen‐containing heterocycles with aryl halides

“…[39][40][41] Also, this strategy provides an excellent opportunity for functionalization of the surface of silica shell and consequently immobilization of variety of organic compounds, transition metal complexes, and homogeneous catalysts on their surface. [42,43] In recent years, magnetic iron oxide core-shell nanocomposites prepared from Fe 3 O 4 and silica shell have been highly regarded due to their widespread applications in various fields [44] such as biomedicine [45][46][47][48][49][50][51][52][53][54][55][56][57][58] and environmental remediation data storage, [49] which all of these applications were not only thank to unique magnetic properties, biocompatibility and easy manipulation of Fe 3 O 4 NPs, but also they possess the both advantages of Fe 3 O 4 nanoparticle core (High aspect ratio, unique catalytic, magnetic and electrical properties) and ability to preparation of shells with different structures. [50] The Fe 3 O 4 NPs, whether alone [51] or supported, [52] have catalytic activity in order to coupling reactions.…”

“…[ 39–41 ] Also, this strategy provides an excellent opportunity for functionalization of the surface of silica shell and consequently immobilization of variety of organic compounds, transition metal complexes, and homogeneous catalysts on their surface. [ 42,43 ]…”

Efficient reduction of nitro compounds and domino preparation of 1-substituted-1H-1,2,3,4-tetrazoles by Pd(ii)-polysalophen coated magnetite NPs as a robust versatile nanocomposite

“…Immobilization of Pd(II)-polysalophen on the magnetite provides a cohesive lattice structure with a high surface-to-volume ratio (according to the proposed structure for the catalyst in Scheme 4) that causes the compounds to penetrate into the catalyst structure in an aqueous medium, and aer the reaction, they are separated from the surface of the catalyst, in full agreement with the suggested mechanisms that water has been used as a solvent in the organic reactions. [41][42][43][44] In order to investigate this phenomenon, in another control test, the catalytic activity of a physical mixture of Pd(II)-polysalophen and Fe 3 O 4 @SiO 2 was studied (Table 5, entry 6).…”