Synthesis, characterisation and application of pyridine-modified chitosan derivatives for the first non-racemic Cu-catalysed Henry reaction

Gonçalves, Fernanda Jorge; Kamal, Fadwa; Gaucher, Anne; Gil, Richard; Bourdreux, Flavien; Martineau‐Corcos, Charlotte; Gurgel, Leandro Vinícius Alves; Gil, Laurent Frédéric; Prim, Damien

doi:10.1016/j.carbpol.2017.12.012

Cited by 19 publications

(16 citation statements)

References 39 publications

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“…Quantifiable yields of modified chitosan derivatives ( L1 and L2 ) were obtained upon the treatment of chitosan with 2‐pyridinecarboxaldehyde or 2‐thiophenecarboxaldehyde in ethanol at a refluxing temperature . Results of 1 H, 13 C NMR spectra, and IR spectra corresponded closely to the literature values …”

Section: Methodsmentioning

confidence: 99%

“…6 Strong and broad OH absorption bands observed at 3435 and 3300 cm −1 in the IR spectra of L1 and L2, respectively. 1 Among these applications, the copper-catalyzed hydroxylation of boronic acids is considered a facile protocol for the preparation of alcohols.…”

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confidence: 97%

“…6 Strong and broad OH absorption bands observed at 3435 and 3300 cm −1 in the IR spectra of L1 and L2, respectively. Quantifiable yields of modified chitosan derivatives (L1 and L2) were obtained upon the treatment of chitosan with 2-pyridinecarboxaldehyde or 2-thiophenecarboxaldehyde in ethanol at a refluxing temperature.…”

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confidence: 97%

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Chemically Modified Chitosan as a Biopolymer Support in Copper‐catalyzed ipso‐Hydroxylation of Arylboronic Acids in Water

Joo

Kwon

Park

2019

Bulletin Korean Chem Soc

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In the past decade, copper complexes have been extensively studied and employed in organic transformations. 1 Among these applications, the copper-catalyzed hydroxylation of boronic acids is considered a facile protocol for the preparation of alcohols. 2 Noting the significant usefulness of copper-catalyzed transformation in organic synthesis, we sought to design an alternative greener pathway utilizing biopolymers and environmentally friendly reaction conditions.To achieve this aim, we were interested in utilizing chitosan generated by the deacetylation of chitin, the second-most abundant natural polysaccaharide after cellulose. Owing to its combination of unique characteristics, chitosan is used in the form of an unmodified polymer or as modified derivatives in various applications. This is especially true in the presence of readily functionalizable primary amino groups that enable easy and effective chemical modification of the material, thereby imparting several desirable chemical and biological properties. 3 In general, the polymer-surface modification through the introduction of new complexation groups may result in the formation of different chelating sites. These sites yield considerable changes in the adsorption capacity and the chemical reactivity of the complexed metal ion in solution.Numerous protocols have been used for chemical modification of chitosan over the last decades. However, the introduction of pyridine derivatives into the chitosan backbone (resulting in Schiff base formation) has recently gained significant attention. One reason for such attention is that this protocol can be applied to metal absorption, antimicrobial activity, gene delivery, sensor applications, and biomedical applications. 4 Presumably, the capacity characterizing imine functionality of chitosan can enhance the metal chelating ability, thereby promoting the catalytic activity of the metal.Considering these aspects, we decided to prepare a modified-chitosan platform with pyridine (L1), and then investigate its applicability in the most robust and useful reaction called ipso-hydroxylation of boronic acids, in conjunction with copper catalyst. In addition, to compare the active role of the pyridine moiety in the chitosan backbone, an alternative chitosan platform (L2) modified with thiophene rings was also prepared and applied to the ipsohydroxylation of boronic acids.A straightforward method for the synthesis of pyridineor thiophene-modified chitosan supports (CTS-Py, L1, and CTS Th, L2, respectively, hereafter) is shown in Scheme 1. Quantifiable yields of modified chitosan derivatives (L1 and L2) were obtained upon the treatment of chitosan with 2-pyridinecarboxaldehyde or 2-thiophenecarboxaldehyde in ethanol at a refluxing temperature. 5 Results of 1 H, 13 C NMR spectra, and IR spectra corresponded closely to the literature values. 6 Strong and broad OH absorption bands observed at 3435 and 3300 cm −1 in the IR spectra of L1 and L2, respectively. The diagnostic peak occurring at 1649 cm −1 corresponded to the conden...

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Section: Methodsmentioning

confidence: 99%

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confidence: 97%

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Chemically Modified Chitosan as a Biopolymer Support in Copper‐catalyzed ipso‐Hydroxylation of Arylboronic Acids in Water

Joo

Kwon

Park

2019

Bulletin Korean Chem Soc

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“…The main differences highlighted in the spectrum of C1 in comparison with chitosan are: (i) the bands at 1604 and 1560 cm -1 , which can be attributed to the stretching of C=C bonds; (ii) the appearance of bands at 1490 and 1432 cm -1 , attributed to the stretching of C=N bonds; and (iii) a band at 836 cm -1 , related to the out-of-plane bending of C−H in the pyridine ring. 29 These changes indicate the introduction of the pyridine ring in chitosan. In addition, the absence of bands in the region of 1540 and 1340 cm -1 , attributed to the asymmetric and symmetric stretching vibration of NO 2 group, 30 in the spectrum of C1, indicates that this material is free of by-product 2,4-dinitroaniline.…”

Section: Resultsmentioning

confidence: 99%

Modification of Chitosan by Zincke Reaction: Synthesis of a Novel Polycationic Chitosan-Pyridinium Derivative

Gonçalves

Freitas

2019

J. Braz. Chem. Soc.

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Chitosan is a biodegradable aminopolysaccharide produced by deacetylation of acetamide groups of chitin, one of the most abundant organic materials in nature. Many different types of organic reactions have been described to modify the functional groups of chitosan and produce materials with applications in a large number of areas. However, the Zincke reaction, an old method which is commonly used to convert primary amine in pyridinium salts, has not been reported to transform the chitosan amino group at C-2 position in glucosamine units. In this paper, our efforts are described to carry out this reaction, employing different conditions to covalently anchor pyridinium salts on the polymer surface. Optimized synthesis conditions using water/ethanol as solvent, triethylamine and Zincke salt excess yielded a novel polycationic chitosan-pyridinium derivative with a weight gain of 52% after 48 h of reaction. The modified biopolymer is water insoluble and exhibits a high degree of chemical modification. The 13 C solid state nuclear magnetic resonance (SS-NMR) spectrum of chitosan-pyridinium derivative showed signals at 147.0, 142.0 and 129.0 ppm, attributed to aromatic carbons, confirming the presence of a quaternary pyridinium ring directly attached to the biopolymer. The Zincke reaction was employed for the first time to modify the chitosan backbone.

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“…Pyridine, as an important aromatic heterocyclic organic solvent and reagent, is used as a pharmacophore for agrochemicals [19,20]. Pyridine and its derivatives have been introduced into all kinds of polysaccharides in order to improve their solubility, physicochemical, and biological properties, which can be applied in mental absorption, gene carrier, antimicrobial, sensor, and biomedical areas [19,21,22,23,24,25]. Jia reported that the solubility and the antifungal activity of the pyridine-grafted chitosan derivatives were improved, which could be used as antifungal agents in the food industry with non-toxicity [19].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization, and Antifungal Activity of Schiff Bases of Inulin Bearing Pyridine ring

et al. 2019

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As a renewable, biocompatible, and biodegradable polysaccharide, inulin has a good solubility in water and some physiological functions. Chemical modification is one of the important methods to improve the bioactivity of inulin. In this paper, based on 6-amino-6-deoxy-3,4-acetyl inulin (3), three kinds of Schiff bases of inulin bearing pyridine rings were successfully designed and synthesized. Detailed structural characterization was carried out using FTIR, 13C NMR, and 1H NMR spectroscopy, and elemental analysis. Moreover, the antifungal activity of Schiff bases of inulin against three plant pathogenic fungi, including Botrytis cinerea, Fusarium oxysporum f.sp.niveum, and Phomopsis asparagi, were evaluated using in vitro hypha measurements. Inulin, as a natural polysaccharide, did not possess any antifungal activity at the tested concentration against the targeted fungi. Compared with inulin and the intermediate product 6-amino-6-deoxy-3,4-acetyl inulin (3), all the synthesized Schiff bases of inulin derivatives with >54.0% inhibitory index at 2.0 mg/mL exhibited enhanced antifungal activity. 3NS, with an inhibitory index of 77.0% exhibited good antifungal activity against Botrytis cinerea at 2.0 mg/mL. The synthesized Schiff bases of inulin bearing pyridine rings can be prepared for novel antifungal agents to expand the application of inulin.

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Synthesis, characterisation and application of pyridine-modified chitosan derivatives for the first non-racemic Cu-catalysed Henry reaction

Cited by 19 publications

References 39 publications

Chemically Modified Chitosan as a Biopolymer Support in Copper‐catalyzed ipso‐Hydroxylation of Arylboronic Acids in Water

Chemically Modified Chitosan as a Biopolymer Support in Copper‐catalyzed ipso‐Hydroxylation of Arylboronic Acids in Water

Modification of Chitosan by Zincke Reaction: Synthesis of a Novel Polycationic Chitosan-Pyridinium Derivative

Synthesis, Characterization, and Antifungal Activity of Schiff Bases of Inulin Bearing Pyridine ring

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