Synthesis of N,N,N-trimethyl chitosan homopolymer and highly substituted N-alkyl-N,N-dimethyl chitosan derivatives with the aid of di-tert-butyldimethylsilyl chitosan
(2011) In Carbohydrate Polymers 86(4). p.1451-1460- Abstract
- A highly chemoselective strategy for the synthesis of N,N,N-trimethyl chitosan (TMC) homopolymer and highly substituted N-alkyl-N,N-dimethyl chitosan derivatives was achieved using di-tert-butyldimethylsilyl-3,6-O-chitosan (di-TBDMS chitosan) as a precursor. The influence of different solvents, reagents and other reaction conditions on the reduction, trimethylation and quaternization of these di-TBDMS chitosan derivatives was studied. Products were characterized by NMR after each step. Di-TBDMS chitosan was reacted with methyl iodide in NMP, giving a 100% substituted TMC with the trimethyl group appearing at 3.35 ppm in H-1 NMR spectrum. N-Propyl-, N-butyl- and N-hexyl-N,N-dimethyl chitosan derivatives were synthesized by stepwise... (More)
- A highly chemoselective strategy for the synthesis of N,N,N-trimethyl chitosan (TMC) homopolymer and highly substituted N-alkyl-N,N-dimethyl chitosan derivatives was achieved using di-tert-butyldimethylsilyl-3,6-O-chitosan (di-TBDMS chitosan) as a precursor. The influence of different solvents, reagents and other reaction conditions on the reduction, trimethylation and quaternization of these di-TBDMS chitosan derivatives was studied. Products were characterized by NMR after each step. Di-TBDMS chitosan was reacted with methyl iodide in NMP, giving a 100% substituted TMC with the trimethyl group appearing at 3.35 ppm in H-1 NMR spectrum. N-Propyl-, N-butyl- and N-hexyl-N,N-dimethyl chitosan derivatives were synthesized by stepwise reductive alkylation of di-TBDMS chitosan, followed by quaternization with dimethyl sulfate in dichloromethane, giving 65-72% substituted N-alkyl-N,N-dimethyl chitosan derivatives under optimized conditions. Analysis of these water-soluble chitosan derivatives by FT-IR, H-1 NMR, C-13 NMR, H-1-H-1 COSY and H-1-C-13 HSQC NMR enabled detailed structural characterization. All peaks could be assigned to N-modification, showing the selectivity of the di-TBDMS protection. (C) 2011 Elsevier Ltd. All rights reserved. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/2180222
- author
- Benediktsdottir, Berglind E. ; Gaware, Vivek S. ; Runarsson, Ögmundur LU ; Jonsdottir, Sigriaur ; Jensen, Knud J. and Masson, Mar
- organization
- publishing date
- 2011
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Chitosan, tert-Butyldimethylsilyl, Deprotection, Stepwise reductive, alkylation, Quaternary chitosan, Trimethyl chitosan
- in
- Carbohydrate Polymers
- volume
- 86
- issue
- 4
- pages
- 1451 - 1460
- publisher
- Elsevier
- external identifiers
-
- wos:000294941100004
- scopus:80052024720
- ISSN
- 0144-8617
- DOI
- 10.1016/j.carbpol.2011.06.007
- language
- English
- LU publication?
- yes
- additional info
- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Organic chemistry (S/LTH) (011001240)
- id
- 6cadb94f-f8bd-461f-8223-5d2082bbfc96 (old id 2180222)
- date added to LUP
- 2016-04-01 10:30:47
- date last changed
- 2022-04-20 02:56:25
@article{6cadb94f-f8bd-461f-8223-5d2082bbfc96, abstract = {{A highly chemoselective strategy for the synthesis of N,N,N-trimethyl chitosan (TMC) homopolymer and highly substituted N-alkyl-N,N-dimethyl chitosan derivatives was achieved using di-tert-butyldimethylsilyl-3,6-O-chitosan (di-TBDMS chitosan) as a precursor. The influence of different solvents, reagents and other reaction conditions on the reduction, trimethylation and quaternization of these di-TBDMS chitosan derivatives was studied. Products were characterized by NMR after each step. Di-TBDMS chitosan was reacted with methyl iodide in NMP, giving a 100% substituted TMC with the trimethyl group appearing at 3.35 ppm in H-1 NMR spectrum. N-Propyl-, N-butyl- and N-hexyl-N,N-dimethyl chitosan derivatives were synthesized by stepwise reductive alkylation of di-TBDMS chitosan, followed by quaternization with dimethyl sulfate in dichloromethane, giving 65-72% substituted N-alkyl-N,N-dimethyl chitosan derivatives under optimized conditions. Analysis of these water-soluble chitosan derivatives by FT-IR, H-1 NMR, C-13 NMR, H-1-H-1 COSY and H-1-C-13 HSQC NMR enabled detailed structural characterization. All peaks could be assigned to N-modification, showing the selectivity of the di-TBDMS protection. (C) 2011 Elsevier Ltd. All rights reserved.}}, author = {{Benediktsdottir, Berglind E. and Gaware, Vivek S. and Runarsson, Ögmundur and Jonsdottir, Sigriaur and Jensen, Knud J. and Masson, Mar}}, issn = {{0144-8617}}, keywords = {{Chitosan; tert-Butyldimethylsilyl; Deprotection; Stepwise reductive; alkylation; Quaternary chitosan; Trimethyl chitosan}}, language = {{eng}}, number = {{4}}, pages = {{1451--1460}}, publisher = {{Elsevier}}, series = {{Carbohydrate Polymers}}, title = {{Synthesis of N,N,N-trimethyl chitosan homopolymer and highly substituted N-alkyl-N,N-dimethyl chitosan derivatives with the aid of di-tert-butyldimethylsilyl chitosan}}, url = {{http://dx.doi.org/10.1016/j.carbpol.2011.06.007}}, doi = {{10.1016/j.carbpol.2011.06.007}}, volume = {{86}}, year = {{2011}}, }