In this study, Fe
3
O
4
@LDH@cysteine–Cu(I) nanoparticles as a novel and recyclable catalytic system was designed and successfully synthesized. These nanoparticles show high catalytic activity for ...preparation of the triazole family through reaction of the organic halides with alkynes in the presence of choline azide as reagent and reaction medium. In addition, Fe
3
O
4
@LDH@cysteine–Cu(I) could be easily recovered and reused for five times without any significant loss in catalytic activity.
Graphic Abstract
The reaction involving benzyl alcohol or benzyl halide and urea, conducted within a mixture comprising choline chloride and aluminium nitrate ionic liquid as the solvent, leads to the synthesis of ...N-monosubstituted urea products. The reaction demonstrates notable to exceptional yields for various derivatives of benzyl alcohols and benzyl halides under the specified reaction conditions. When benzyl halides and benzyl alcohol undergo reactions with urea in the presence of the prepared ionic liquid, a sole selective pathway is observed, resulting in a considerable yield of N-monosubstituted urea products. This approach offers several advantages, including reaction selectivity, high product efficiency, facile separability of products, the environmentally benign nature of the solvent, and the omission of expensive and hazardous catalysts. These attributes underscore the significance of such pioneering reactions. Due to the markedly polar attributes and insolubility of the resulting products in water, facile separation from the reaction milieu is facilitated through the introduction of water into the reaction mixture. Consequently, this specific ionic liquid methodology provides an uncomplicated and selective avenue for the synthesis of compounds possessing noteworthy pharmaceutical and industrial utility.
Graphical abstract
Superparamagnetic nanoparticles of modified sulfuric acid (γ-Fe2O3@SiO2-OSO3H) represent a straightforward and green catalyst for the rapid synthesis of aminoimidazopyridine skeletons via the ...Ugi-like Groebke-Blackburn-Bienaymé three-component reaction. The γ-Fe2O3@SiO2-OSO3H catalyst could be recovered and reused in five reaction cycles, giving a total TON=453. The products were prepared under solvent-free conditions without any additives.
Abstract
An MIL-100 (Fe)/graphene oxide (GO) hybrid, a fairly-known composite, was made through a simple one-step procedure and played a highlighted role in the photo-induced oxidative ...functionalization of the benzylic C–H bond. To identify the given binary composite, various techniques were applied: FT-IR, P-XRD, SEM, nitrogen absorption–desorption analysis, TGA, TEM, and UV–Visible DRS spectra. Proportions of GO used within the structure of the prepared composite differently ranged from low to high amount, and the most optimized ratio met at 38.5% of GO as the most efficient catalyst. Additionally, the reaction ran in Glycerol/K
2
CO
3
(2:1) as the optimal solvent. The elemental roles of O
2
·
−
and OH
−
were supposed to be the major ones for running a tandem oxidation-Knoevenagel reaction. The heterogeneity and reusability of the catalyst were also examined and confirmed after five successive runs.
In this paper, an economic statistical design for individual samples of quality characteristics which have Exponential distributions presented with variable sampling method. To do this, first the ...Exponential distribution is transformed to a Normal distribution Using Nelson's approximation, then using Costa and Rahim's economic model, an economic statistical design is obtained for the transformed data. The transition probability matrix and the economic and statistical parameters are formulated. Optimal design parameters (sampling interval, warning and control limits) are determined using Artificial Bee Colony algorithm and a sensitivity study is done for various values of the model parameters. Based on the results, the mentioned method in compared with the fixed ratio sampling method is more effective when a moderate shift occurs. A simulated example is given also to illustrate the proposed design.
The effect of four cationic ionic liquids (ILs), 1-butyl-3-methylimidazolium chloride (BMImCl), 1-butyl-3-methylimidazolium bromide (BMImBr), 1-hexyl-3-methylimidazolium chloride (HMImCl), and ...1-hexyl-3-methyl-imidazolium bromide (HMImBr) on surface activity and micellization of an anionic surfactant, sodium dodecyl sulfate (SDS), is studied. The thermodynamic data on micellization and surface adsorption are obtained from tensiometry and conductometry. The applicability of UV–visible spectroscopy to study of SDS/IL systems is also investigated using Crystal Violet as the probe. Cyclic voltammetry, dynamic light scattering, and TEM imaging are employed to investigate the size and morphology of aggregates. According to the findings, addition of butyl-chained ILs to aqueous SDS results in only a slight gradual increase in average aggregate size whereas the size of SDS assemblies are dramatically increased upon addition of hexyl-chained ILs. It is proposed that BMIm+ cations of the IL undergo Coulombic attractive interactions with anionic headgroups adsorbed at the micellar surface in aqueous SDS whereas HMIm+ interact through hydrophobic chain–chain attractions as well. Thus, mixed micellization results in formation of vesicles. A micellar phase change from vesicles to micelles takes place at higher SDS/IL ratios. All of these processes are successfully tracked by the employed techniques.
In this study, novel nanomagnetic catalysts, namely Fe
2
O
3
-MgO@choline formate (Ch. F.) and Fe
2
O
3
-MgO@choline cyanide (Ch. CN), were synthesized through immobilizing choline-based ion liquids ...to magnetic support via a simple and cost-effective methodology. FT-IR, TGA, FE-SEM, VSM, EDS, BET, and XRD techniques were employed to assess and characterize these organic–inorganic compounds. Following the successful preparation of nanoparticles, the catalysts were utilized in Knoevenagel and benzoin condensations. Fe
2
O
3
-MgO@Ch.F. exhibited exceptional activity in Knoevenagel condensation under solvent-free conditions at room temperature, achieving high yields (91–98%) in a short timeframe. Similarly, Fe
2
O
3
-MgO@Ch.CN demonstrated remarkable activity in benzoin condensation under environmentally friendly solvent conditions, yielding higher isolated yields (76–88%). Furthermore, these magnetically recyclable multifunctional catalysts displayed the ability to be reused up to five times without a significant loss in efficiency. Additionally, the heterogeneity of this nanocatalyst was investigated using the hot filtration technique. The findings indicated that the reaction primarily occurs via a heterogeneous pathway.
It is desired to develop a catalytic system for Ritter reaction with the green and fast method, this work designed and synthesized intercalated nafion in layered double hydroxide (LDH) by the ...ultrasonic method and applied for Ritter reaction of benzyl alcohols with nitriles in water as a green solvent under ultrasonic condition.
Graphic Abstract
Time and again, SBA-15-based composites as mesoporous materials and the incorporation of transition metals in them have been attracting dramatic attention in the field of catalysis due to their ...remarkable features. In this paper, the activity of SBA-15 supported ionic liquid–Pd(ii) has been investigated in the catalytic transfer hydrogenation of nitroarenes with formic acid as a hydrogen donor at room temperature in water medium, and the oxidation of benzyl alcohols to benzaldehyde derivatives under atmospheric oxygen at high temperature. This novel nanocatalyst was characterized by FT-IR, SA-XRD, BET, BJH, TGA, FE-SEM, TEM, and ICP as the most commonplace techniques for analyzing its characteristics to be revealed as truth. Furthermore, the EDX analysis illustrates the grafting of the ionic liquid–Pd(ii) into SBA-15. The catalyst showed high stability under reaction conditions, and can be recovered and reused for at least 15 and 6 reaction runs in oxidation and reduction reactions, respectively.
Ultrasound irradiation as an environmentally friendly and inexpensive method successfully applied for the synthesis of two-dimensional (2D) and three-dimensional (3D) metal–organic frameworks (MOFs). ...Sonochemically synthesized AM-Co1 and AM-Co2 powder has been employed as a green heterogeneous catalyst for the oxidative amidation reaction. The results show that AM-Co1 with a two-dimensional (2D) structure can act as an excellent catalyst for this reaction under ultrasonic irradiation compared to AM-Co2 with a three-dimensional (3D) structure. According to green principles, we used water as a green solvent and air as an oxidant for the oxidative amidation reaction. A wide variety of aldehydes and amines have been used for the synthesis of amides in good to excellent yields (75–90%). Also, the MOF catalyst could be recovered and reused several times without loss of activity.
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