Imidazole-Functionalized Fe3O4/Chloro-Silane Core-Shell Nanoparticles: an Efficient Heterogeneous Organocatalyst for Esterification Reaction

Fattahi, Nadia; Ramazani, Ali; Kinzhybalo, Vasyl

doi:10.1007/s12633-017-9757-0

Cited by 21 publications

(5 citation statements)

References 43 publications

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“…18,19 Thereafter, the N-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride (EDC•HCl) was added into the ongoing reaction to form the O-acylisourea intermediate via an ion pair transfer; this O-acylisourea intermediate then reacted with the already present catalytic amount of DMAP (strong nucleophile) to form an acyl pyridinium specie, which acts as an acyl-transfer reagent and reacts with the −OH group of LSF to form ester linkage (−COOR′) between the fatty acid and LSF. 20 Herein, DMAP provided an appreciable yield of the product by preventing the formation of the byproduct (Nacylurea) during the reaction. This mechanism is also termed as the Steglich esterification.…”

Section: ■ Discussion and Conclusionmentioning

confidence: 80%

“…The prodrugs were synthesized by conjugation of LSF with different categories of fatty acids LA, OA, PA, and ALA, all having the same structural chemistry (−COOH) at one end of carbon facilitating a similar procedure for the synthesis for all of the prodrugs. The mechanism is based on carbodiimide coupling, where FAs having free −COOH group was dissolved in DCM followed by the addition of 4-dimethylaminopyridine (DMAP) to activate the −COOH group, which forms an anhydride form of fatty acid. , Thereafter, the N -(3-dimethylaminopropyl)- N -ethylcarbodiimide hydrochloride (EDC·HCl) was added into the ongoing reaction to form the O -acylisourea intermediate via an ion pair transfer; this O -acylisourea intermediate then reacted with the already present catalytic amount of DMAP (strong nucleophile) to form an acyl pyridinium specie, which acts as an acyl-transfer reagent and reacts with the −OH group of LSF to form ester linkage (−COOR′) between the fatty acid and LSF . Herein, DMAP provided an appreciable yield of the product by preventing the formation of the byproduct ( N -acylurea) during the reaction.…”

Section: Discussion and Conclusionmentioning

confidence: 99%

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Role of Chain Length and Degree of Unsaturation of Fatty Acids in the Physicochemical and Pharmacological Behavior of Drug–Fatty Acid Conjugates in Diabetes

et al. 2021

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Several drug–fatty acid (FA) prodrugs have been reported to exhibit desirable physicochemical and pharmacological profile; however, comparative beneficial effects rendered by different FAs have not been explored. In the present study, four different FAs (linoleic acid, oleic acid, palmitic acid, and α-lipoic acid) were selected based on their chain length and degree of unsaturation and conjugated to Lisofylline (LSF), an antidiabetic molecule to obtain different drug–FA prodrugs and characterized for molecular weight, hydrophobicity, purity, self-assembly, and efficacy in vitro and in vivo in type 1 diabetes model. Prodrugs demonstrated a 2- to 6-fold increase in the plasma half-life of LSF. Diabetic animals treated with prodrugs, once daily for 5 weeks, maintained a steady fasting blood glucose level with a significant increase in insulin level, considerable restoration of biochemical parameters, and preserved β-cells integrity. Among the different LSF-FA prodrugs, LSF-OA and LSF-PA demonstrated the most favorable physicochemical, systemic pharmacokinetic, and pharmacodynamic profiles.

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Section: ■ Discussion and Conclusionmentioning

confidence: 80%

Section: Discussion and Conclusionmentioning

confidence: 99%

Role of Chain Length and Degree of Unsaturation of Fatty Acids in the Physicochemical and Pharmacological Behavior of Drug–Fatty Acid Conjugates in Diabetes

et al. 2021

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“…It also contains hydrolyzable groups on the silicon atom. The hydrolysable groups are typically alkoxy (i.e., methoxy, ethoxy) [ 33 , 34 ] or chlorine groups [ 35 , 36 ]. The modification of the NPs surface with alkoxysilanes comprises two steps.…”

Section: Introductionmentioning

confidence: 99%

Morphological and Structural Properties of Amino-Functionalized Fumed Nanosilica and Its Comparison with Nanoparticles Obtained by Modified Stöber Method

et al. 2020

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In industry, silica nanoparticles (NPs) are obtained by the fuming and the precipitation method. Fumed silica NPs are commonly used in the preparation of nanocomposites because they have an extremely low bulk density (160–190 kg/m3), large surface area (50–600 m2/g), and nonporous surface, which promotes strong physical contact between the NPs and the organic phase. Fumed silica has fewer silanol groups (Si–OH) on its surface than the silica prepared by the Stöber method. However, the number of –OH groups on the fumed silica surface can be increased by pretreating them with sodium hydroxide (NaOH) before further surface modification. In this study, the effectiveness of the NaOH pretreatment was evaluated on commercial fumed silica NPs with a surface area of 200 m2/g. The number of surface –OH groups was estimated by potentiometric titration. The pretreated fumed NPs, and the precipitated NPs (prepared by the Stöber method) were modified with 3-aminopropyltriethoxysilane (APTES) to obtain A200S and nSiO2-APTES, respectively. The NPs were characterized using electron dispersive scanning (EDS), scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), BET (Brunauer–Emmett–Teller) analysis, and ζ-potential. XRD confirmed the presence of the organo-functional group on the surface of both NPs. After the amino-functionalization, the ζ-potential values of the nSiO2 and A200 changed from −35.5 mV and −14.4 mV to +26.2 mV and +11.76 mV, respectively. Consequently, we have successfully synthesized functionalized NPs with interesting, specific surface area and porosity (pore volume and size), which can be attractive materials for chemical and energy industries.

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“…These materials were tailored specially to give desirable properties of the polymer as well as inorganic materials and suppress the undesirable ones, finally leading to an advanced framework with a wide range of applications . Desired properties of organic–inorganic hybrid materials are better chemical, mechanical, thermal, and biological stability compared with their pure organic and inorganic materials . The commonly used inorganic materials include silica, layer silicate, carbon nanotube, CaCO 3 , and others …”

Section: Introductionmentioning

confidence: 99%

Synthesis of polymer‐silica hybrid‐supported catalysts for solvent‐free oxidation of ethylbenzene with TBHP

Chaudhary

Sharma

2020

Asia-Pacific J Chem Eng

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Polymer-silica hybrid support was synthesized, and Cu (II), Co (II), Mn (II), and Ni (II) metals were loaded over hybrid support by incipient impregnation method. Oxidation of ethylbenzene was performed for catalytic evaluation of catalysts at different reaction conditions, that is, the mole ratio of ethylbenzene to TBHP and reaction temperature. The main reaction product was acetophenone along with benzaldehyde as the minor product. The highest ethylbenzene conversion (96.5%) was attained at a 1:3 mole ratio of ethylbenzene to TBHP and temperature at 100 C. Activation energy and reusability of the catalysts were also determined, and results showed that they can be easily reused three times without much loss in their structural and catalytic properties.

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Imidazole-Functionalized Fe3O4/Chloro-Silane Core-Shell Nanoparticles: an Efficient Heterogeneous Organocatalyst for Esterification Reaction

Cited by 21 publications

References 43 publications

Role of Chain Length and Degree of Unsaturation of Fatty Acids in the Physicochemical and Pharmacological Behavior of Drug–Fatty Acid Conjugates in Diabetes

Role of Chain Length and Degree of Unsaturation of Fatty Acids in the Physicochemical and Pharmacological Behavior of Drug–Fatty Acid Conjugates in Diabetes

Morphological and Structural Properties of Amino-Functionalized Fumed Nanosilica and Its Comparison with Nanoparticles Obtained by Modified Stöber Method

Synthesis of polymer‐silica hybrid‐supported catalysts for solvent‐free oxidation of ethylbenzene with TBHP

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