Preparation of highly regioselective chitosan derivatives via “click chemistry”

• Published in: Carbohydrate polymers Vol. 85; no. 3; pp. 653 - 657
• Main Authors: Ifuku, Shinsuke, Wada, Masahiro, Morimoto, Minoru, Saimoto, Hiroyuki
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.06.2011; Elsevier
• Subjects: Applied sciences; ascorbic acid; bromination; carbon; Chitosan; Click chemistry; Exact sciences and technology; Fourier transform infrared spectroscopy; Huisgen cycloaddition; Natural polymers; nuclear magnetic resonance spectroscopy; Physicochemistry of polymers; Regioselective modification; stable isotopes; Starch and polysaccharides; triethylamine; Chitosan; Click chemistry; Regioselective modification; Huisgen cycloaddition; 1,3-Dipolar cycloaddition; Regioselectivity; Bromination; Experimental study; N-Bromosuccinimide; Azides; Chemical modification; Triazole derivative polymer; Chitosan derivatives; Imidation; Preparation; Chemical protection; Oside polymer; Nucleophilic substitution
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2011.03.030

Highly regioselective chitosan derivatives were achieved by copper-catalyzed Huisgen cycloaddition, known as an ideal reaction for click chemistry, using 6-azido-6-deoxy-chitosan derivative. The azide moiety introduced through regioselective bromination and azidation of chitosan was successfully converted with ethynyl compounds having functional groups (hydroxymethyl and phenyl groups) in the presence of copper(II) sulfate, sodium ascorbate and triethylamine. FTIR, elemental analysis, 1H NMR, and 13C NMR spectra showed that C-6 positions of the chitosan derivative were regioselectively transferred by these functional groups with 1,4-triazole linker, and the DS values were approximately 1.