An Ionic Liquid Solution of Chitosan as Organocatalyst

Heckel, Tatjana; Konieczna, Dagny Dagmara; Wilhelm, René

doi:10.3390/catal3040914

Cited by 17 publications

(11 citation statements)

References 32 publications

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“…The result suggested that cyclic amines with moderate alkalinity and two active centers exhibited high activity. Plausible pathways are shown in Scheme 2 and we consider that the ratio of the aldol condensation was promoted by the hydrogen bonding between the amino group or the hydroxy group of 3-pyrrolidinamine or 3-pyrrolidinol and the aldehyde [24,25]. …”

Section: Resultsmentioning

confidence: 99%

Solvent-Free Selective Condensations Based on the Formation of the Olefinic (C=C) Bond Catalyzed by Organocatalyst

Song

Jin

et al. 2016

Catalysts

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Pyrrolidine and its derivatives were used to catalyze aldol and Knoevenagel condensations for the formation of the olefinic (C=C) bond under solvent-free conditions. The 3-pyrrolidinamine showed high activity and afforded excellent yields of α,β-unsaturated compounds. The aldol condensation of aromatic/heterocyclic aldehydes with ketones affords enones in high conversion (99.5%) and selectivity (92.7%). Good to excellent yields of α,β-unsaturated compounds were obtained in the Knoevenagel condensation of aldehydes with methylene-activated substrates.

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Section: Resultsmentioning

confidence: 99%

Solvent-Free Selective Condensations Based on the Formation of the Olefinic (C=C) Bond Catalyzed by Organocatalyst

Song

Jin

et al. 2016

Catalysts

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“…It was shown (Figure 5), that while the freeze-drying method originates a porous membrane structure, oven drying produces compact films, with a smoother surface using water as an anti-solvent [78]. Additionally, deacetylation into chitosan does not occur with the use of ILs [79]. Other ILs such as choline hexanoate ([Ch][Hex]) and choline citrate ([Ch][Cit]) have also been successful in this process [80].…”

Section: Dissolutionmentioning

confidence: 99%

Ionic Liquid-Based Materials for Biomedical Applications

Correia

Fernandes

et al. 2021

Nanomaterials

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Ionic liquids (ILs) have been extensively explored and implemented in different areas, ranging from sensors and actuators to the biomedical field. The increasing attention devoted to ILs centers on their unique properties and possible combination of different cations and anions, allowing the development of materials with specific functionalities and requirements for applications. Particularly for biomedical applications, ILs have been used for biomaterials preparation, improving dissolution and processability, and have been combined with natural and synthetic polymer matrixes to develop IL-polymer hybrid materials to be employed in different fields of the biomedical area. This review focus on recent advances concerning the role of ILs in the development of biomaterials and their combination with natural and synthetic polymers for different biomedical areas, including drug delivery, cancer therapy, tissue engineering, antimicrobial and antifungal agents, and biosensing.

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“…In 2013, Wilhelm and co‐workers applied homogeneous solutions of chitosan with different molecular weights (between 100k and 300k g mol −1 ) in various ionic liquids to catalyze the asymmetric aldol reaction (Scheme ) . Purified chitosan (1 g) was dissolved in ionic liquid (10 g) at 70 °C.…”

Section: Natural Polysaccharide‐based Organocatalystsmentioning

confidence: 99%

“…In 2013, Wilhelma nd co-workers appliedh omogeneous solutions of chitosan with different molecular weights (between 100k and 300k gmol À1 )i nv arious ionic liquids to catalyzet he asymmetrica ldol reaction (Scheme 6). [41] Purified chitosan (1 g) was dissolved in ionic liquid (10 g) at 70 8C. The catalytic ability of this system provedt ob ed ependent on the counteraniono f the cationic ionic liquid and on the ability of the ionic liquid to form hydrogen bonds, thus disaggregating the polymer chains.…”

Section: Aldol Reactionmentioning

confidence: 99%

Valorization of Waste: Sustainable Organocatalysts from Renewable Resources

Meninno

2019

ChemSusChem

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443 Reviews Figure 2. Potential organocatalytic modes of activatione xhibited by chitosan.Scheme2.Monoglycerides ynthesis by ring opening of the glycidol catalyzed by chitosan. 444 ReviewsScheme3.Aldol reaction between 4-nitrobenzaldehyde (1)a nd cyclohexanone (2)promoted by chitosan hydrogel beads. Scheme4.Aldol reactionscatalyzed by dried chitosan gels and proposed catalytic modes of activation. 445 Reviews Scheme5.Aldol reaction in water promoted by chitosan aerogel beads (additivesu sed at 20 mol %: DNP = 2,4-dinitrophenol, SA = stearic acid, SDS = sodium dodecyl sulfate,B oc = tert-butyloxycarbonyl; ee = enantiomeric excess). Scheme6.Aldol reactionscatalyzedb yc hitosan in 1-butyl-3-methylimidazolium bromide ([bmim][Br])at3 78C. 446 Reviews Scheme16. Asymmetric aldol reaction in water catalyzedb yc hitosan-supported cinchonine. Scheme15. Chitosan-catalyzed transamidation of carboxamides with amines under neat conditions. 450 Reviews Scheme17. Knoevenagelcondensation of challenging aldehydes promoted by native and modified chitosan-derived hydrogels ([a] conversion valuesare reported). 458 Reviews Scheme33. Stereoselective Michael reaction catalyzedbyan aturalpinanederived bifunctional organocatalyst. Scheme32. Stereoselective Mannich reaction catalyzed by d-glucosamine-derived organocatalyst and the hypothetical reaction TS. 460 Reviews Scheme35. a) Synthesis of organocatalyst 52 derived from abietic acid. b) Asymmetric direct aldol reaction catalyzed by 52.c)Proposed TS model. 461 ReviewsScheme42. a) Reductive transformation of CO 2 with amines into formamidesand methylamines organocatalyzedbyl ecithin, and b) plausible reaction mechanism.

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An Ionic Liquid Solution of Chitosan as Organocatalyst

Cited by 17 publications

References 32 publications

Solvent-Free Selective Condensations Based on the Formation of the Olefinic (C=C) Bond Catalyzed by Organocatalyst

Solvent-Free Selective Condensations Based on the Formation of the Olefinic (C=C) Bond Catalyzed by Organocatalyst

Ionic Liquid-Based Materials for Biomedical Applications

Valorization of Waste: Sustainable Organocatalysts from Renewable Resources

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