Bromozincate ionic liquids in the Knoevenagel condensation reaction

Player, Lisa C.; Chan, Bun; Turner, Peter; Masters, Anthony F.; Maschmeyer, Thomas

doi:10.1016/j.apcatb.2017.09.021

Cited by 33 publications

(12 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Knoevenagel condensation reaction, a nucleophilic addition of an active hydrogen compound to an aldehyde, is one of the most important carbon–carbon bond formation methodologies for the production of pharmaceuticals, fine chemicals, organic solar polymers, and so forth. − Originally, the reaction is catalyzed by weak bases, such as amines, pyridines, and piperidines, in a homogeneous system. , Recently, heterogeneous catalysts were prepared for the highly efficient and environment-friendly Knoevenagel condensation reaction. − For example, zeolitic imidazolate framework-8 (ZIF-8), a typical metal–organic framework, has been developed to serve as an efficient Lewis acid catalyst for the Knoevenagel reaction at room temperature. , Up to now, however, only few studies have been done on CC bond formation by Knoevenagel condensation. According to the reports of Rajasekaran and Galzi, Knoevenagel compounds could undergo hydrolytic cleavage in the presence of a base in aqueous medium.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Covalent C═C Bond, Cross-Linked, Injectable, and Self-Healable Hydrogels via Knoevenagel Condensation

et al. 2020

View full text Add to dashboard Cite

Hydrogels have a wide range of applications in the fields of biomedicine, flexible electronics, and bionics. In this study, injectable and self-healable hydrogels were first prepared based on a dynamic covalent CC bond formed via the Knoevenagel condensation reaction between poly(ethylene glycol) dicyanoacetate and water-soluble poly(vanillin acrylate). Three kinds of catalysts (phosphate buffer, zeolitic imidazolate framework-8, and tertiary amine) were used in Knoevenagel condensation for preparing hydrogels. All hydrogels in this study could be formed in situ, and their gelation time ranged from seconds to minutes. The properties and application of hydrogels could be customized according to the type of catalyst employed. 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) results indicated that all the components and hydrogels exhibited low toxicity, and the hydrogels could be used as 3D cell culture scaffolds. Because of the dynamic covalent CC bond formed by Knoevenagel condensation, the resultant hydrogels were found to be dynamic and showed good self-healing properties. This work presents a new dynamic covalent chemistry for the preparation of self-healable materials.

show abstract

Section: Introductionmentioning

confidence: 99%

Dynamic Covalent C═C Bond, Cross-Linked, Injectable, and Self-Healable Hydrogels via Knoevenagel Condensation

et al. 2020

View full text Add to dashboard Cite

show abstract

“…ILs generally present interesting physical and chemical properties including negligible vapor pressure, nonflammability, high electrochemical and thermal stabilities, and high CO 2 solubility. The high level of tunability of both the cation and/or anion structure has a direct impact on these properties, making ILs appealing to many fields of research, e.g., chemical reactions and/or catalysis, 8 solid−liquid extraction, 9 and gas separation/ absorption, 10 In parallel, new solid microporous materials with potential applicability in gas adsorption, namely, CO 2 , have recently been developed. Several materials traditionally employed as adsorbents are silica gels, activated carbons, and zeolites.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Ionic Liquid-Impregnated Metal–Organic Frameworks for CO₂/CH₄ Separation

Ferreira

Ribeiro

Mota

et al. 2019

ACS Appl. Nano Mater.

View full text Add to dashboard Cite

A large set of distinct ionic liquid (IL)-impregnated metal–organic framework (MOF) composites were produced by a direct-contact method to study their performance as sorbents for gas separation applications. The IL anion/cation impact on the sorption capacity and ideal CO2/CH4 selectivity were fully detailed. A reproducible methodology and rigorous characterization were defined to evaluate the IL impact on the IL@ZIF-8 performance. Results show that the IL impregnation was successful, the ZIF-8 structure is conserved after IL incorporation, and the microporous composites are thermally stable at the working temperatures. CO2 and CH4 adsorption–desorption equilibria in the composites were measured at the temperature of 303 K and up to 16 bar of pressure. The respective data were then compared with that obtained for pristine ZIF-8. At high pressure, all composites show reversible, although inferior, gas uptake (total pore volume loss due to IL pore occupation/blockage). At low pressure, because of synergistic effects arising from IL–MOF interactions, one composite displays superior CO2 uptake compared to ZIF-8. Four IL@ZIF-8 composites show distinct low-pressure trends from ZIF-8, due to their IL structure/size, with an increase in the selectivity that can be above 40% at 0.5 bar. An IL-free basis analysis was also assessed considering a normalization of the gas uptake per gram of ZIF-8 in the composites. This shows that ILs do have an impact on the adsorption capacity of the composites. A new approach, based on the materials’ pore volume as a key factor, is discussed toward the sorption data of the IL@ZIF-8 composites. Through mapping of the composites data, it is possible to understand the effect of the IL for high- and low-pressure applications. The results obtained herein indicate that IL@MOF composites are potential alternative materials for low-pressure gas separation.

show abstract

“…These results mostly follow the utilization of experimental “green” conditions, such as the use of green solvents (water and ethanol) or none solvent at all; grinding or ball milling as mechanical stirring conditions, low temperature and time values and minimal amount of recoverable catalyst. As reported in Table , chitosan, ionic liquids,, molecular metallic catalyst, the combination of both factors in the form of bromozincate ionic liquids or tungsten immobilized heterogeneous catalysts reach moderate to good TON values in the selective synthesis of 2‐benzylidenemalononitrile at the cost of some green principles, such as, high temperatures or long reaction times. In comparison, the materials synthesized in this work, TTS‐MSN‐Co, TTS‐MSN‐G and TTS‐MNPs, show excellent TON values at room temperature and low reaction times.…”

Section: Resultsmentioning

confidence: 84%

Heterogeneous Organocatalysts Based on a Triazine‐Triazole Silane Ligand

2018

View full text Add to dashboard Cite

Robust and non-air-sensitive metal-free triazine-triazole heterogeneous organocatalysts were prepared. The synthetic procedure involved the co-condensation of a bridged tris silane precursor with tetraethyl orthosilicate (TEOS) in the presence of cetyltrimethylammonium bromide (CTAB). In addition, the silane precursor was anchored post-synthesis onto mesoporous silica nanoparticles and used to stabilize magnetic nanoparticles. The organocatalysts were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), N 2 adsorption-desorp- [a]

show abstract

Bromozincate ionic liquids in the Knoevenagel condensation reaction

Cited by 33 publications

References 27 publications

Dynamic Covalent C═C Bond, Cross-Linked, Injectable, and Self-Healable Hydrogels via Knoevenagel Condensation

Dynamic Covalent C═C Bond, Cross-Linked, Injectable, and Self-Healable Hydrogels via Knoevenagel Condensation

Ionic Liquid-Impregnated Metal–Organic Frameworks for CO₂/CH₄ Separation

Heterogeneous Organocatalysts Based on a Triazine‐Triazole Silane Ligand

Contact Info

Product

Resources

About

Bromozincate ionic liquids in the Knoevenagel condensation reaction

Cited by 33 publications

References 27 publications

Dynamic Covalent C═C Bond, Cross-Linked, Injectable, and Self-Healable Hydrogels via Knoevenagel Condensation

Dynamic Covalent C═C Bond, Cross-Linked, Injectable, and Self-Healable Hydrogels via Knoevenagel Condensation

Ionic Liquid-Impregnated Metal–Organic Frameworks for CO2/CH4 Separation

Heterogeneous Organocatalysts Based on a Triazine‐Triazole Silane Ligand

Contact Info

Product

Resources

About

Ionic Liquid-Impregnated Metal–Organic Frameworks for CO₂/CH₄ Separation