Mini-review: Ferrite nanoparticles in the catalysis

Magnetic nanoparticles have emerged recently as an alternative for the easy separation of nanosized catalysts from reaction mixtures by employing an external magnetic field. These magnetic nanoparticles have been used as supports for catalysts and/or as part of an active catalytic site. Herein, special attention is given to identify the main synthetic steps required to develop both precious‐ and nonprecious‐metal‐catalyzed CC and CX coupling reactions by using magnetically separable catalysts.

Recent Applications of Magnetically Recoverable Nanocatalysts in CC and CX Coupling Reactions

N-Thiocyanatosaccharin (R1) was readily prepared from the sweet additive Saccharin in two steps with a 71% overall yield. By applying this new reagent to diverse nucleophiles such as benzothiophenes, indoles, oxindoles, aromatic amines, phenols, β-keto carbonyl compounds, and aromatic ketones, a novel electrophilic thiocyanation reaction was achieved with high yields (up to 99%). The potential recycling of Saccharin, the wide scope of substrates, and the mild reaction conditions made this protocol much more practical.

N-Thiocyanatosaccharin: A "Sweet" Electrophilic Thiocyanation Reagent and the Synthetic Applications

In this article, we have introduced catalytic application of copper ferrite nanoparticles (CuFe 2 O 4 ) for one-pot odorless production of aryl alkyl thioethers using thiourea and alkyl bromides in wet polyethylene glycol as a green solvent. The catalyst was also successfully applied for one-pot synthesis of symmetrical diaryl trithiocarbonates via the reaction of sodium sulfide, carbon disulfide and aryl iodides under heterogeneous reaction condition. Magnetic copper ferrite nanoparticles were synthesized using iron (III) chloride and copper (II) chloride, and characterized using XRD, FT-IR, AAS, and TEM analysis. The catalyst was recycled using simple magnetic separation and reused for the five consecutive runs in the reaction of iodobenzene, thiourea and benzyl bromide without appreciable loss of activity.

Synthesis and characterization of magnetic copper ferrite nanoparticles and their catalytic performance in one-pot odorless carbon-sulfur bond formation reactions

A new colorimetric chemosensor 1 for the sequential detection of Ni2+ and CN− was designed and synthesized. The presence of Ni2+ led to a distinct naked-eye color change from colorless to yellow in a near-perfect aqueous solution. To examine the binding mechanism of 1 with Ni2+, UV3–vis spectroscopy, ESI-mass spectrometry analysis and DFT calculations were conducted. The detection limit of 1 for Ni2+ was down to nanomolar concentration (57 nM). Also, the sensing ability of 1 for Ni2+ was successfully carried out in real water samples (tap, drinking and sewage water). Moreover, the resulting 1-Ni2+ complex acted as an efficient colorimetric chemosensor for CN− via a color change from yellow to colorless. Therefore, chemosensor 1 can be employed as a practical colorimetric chemosensor for detecting of both Ni2+ and CN−.

A novel colorimetric chemosensor for the sequential detection of Ni2+ and CN− in aqueous solution

Copper ferrite nano material as reusable heterogeneous initiator in the synthesis of β, γ-unsaturated ketones and allylation to acid chlorides are presented The reaction of allylichalides with various acid chlorides is achieved in the presence of copper ferrite nano powders at room temperature in tetrahydrofuran (THF) The present method is first of its kind in the synthesis of title compounds without any additive/ co-catalyst The nano catalyst is easily recovered and its reusability is recorded

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Nano copper ferrite: A reusable catalyst for the synthesis of β , γ -unsaturated ketones

An efficient and solvent -free approach for regioselective thiocyanation of various substituted anilines and indoles is described. The reaction performed both on and off the alumina surface under microwave conditions. Microwave irradiation reactions under solvent-free conditions resulted in a “green-chemistry” procedure, by which thiocyanation was achieved. In comparison to other reported methods for regioselective thiocyanation of anilines and indoles on the focus of reaction times, yields and usage of oxidizing agents, the present method shows considerable advantages.

Microwave-assisted neat reaction technology for regioselective thiocyanation of substituted anilines and indoles in solid media

A thio carboxylic acid derivative: 2-aminocyclopent-1-ene-1-carbodithioic acid (ligand) was synthesized and characterized. It was used as a colorimetric chemo sensor (chads) for Ni. The absorption maximum of ligand and Ni shows a shift from 390 nm to 420 nm in absence of buffer solutions. The change in color is very easily observed by the naked eye, while other metal cations, such as Fe, Co, Hg, Zn, Cd, Cu, Fe, Ag, Pb, alkali metal and alkaline earth metal cations do not induce such a change with these chads. The response time upon exposure to Ni is instantaneous. The significant problem of nickel poisoning requires new methods of detection that are sensitive and selective. Here we report a simple system that takes advantage of the unique optical properties generated by ACDA-

A simple inexpensive detection method of nickel in water using optical sensor.

An efficient and economically feasible microwave-assisted eco-friendly reaction was developed for the preparation of �-amino alcohols from aminolysis of epoxides. The reaction was executed on the reusable perchloric acid supported silica matrix (HClO 4-SiO 2) surface in a microwave. The yields of �-amino alcohols are uniformly good. The applicability of the catalyst was studied in the synthesis of propranolol, a cardiovascular drug. The results were presented.

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Silica Perchloric Acid Matrix Supported Ring Opening of Epoxide Under Microwave Radiation

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K. Nagalakshmi

Papers

Nano copper ferrite: A reusable catalyst for the synthesis of β , γ -unsaturated ketones

Microwave-assisted neat reaction technology for regioselective thiocyanation of substituted anilines and indoles in solid media

A simple inexpensive detection method of nickel in water using optical sensor.

Silica Perchloric Acid Matrix Supported Ring Opening of Epoxide Under Microwave Radiation

A Simple and Straightforward Synthesis of Cinnamic acids and Ylidene Malononitriles via Knoevenagel Condensation Employing DABCO as Catalyst