{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T04:47:35Z","timestamp":1791434855276,"version":"4.3.3"},"reference-count":50,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2019,11,4]],"date-time":"2019-11-04T00:00:00Z","timestamp":1572825600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>N,N,N-Trimethyl chitosan (TMC) is one chitosan derivative that, because of its improved solubility, has been studied for industrial and pharmaceutic applications. Conventional methods for the synthesis of TMC involve the use of highly toxic and harmful reagents, such as methyl iodide and dimethyl sulfate (DMS). Although the methylation of dimethylated chitosan to TMC by dimethyl carbonate (DMC, a green and benign methylating agent) was reported recently, it involved a formaldehyde-based procedure. In this paper we report the single-step synthesis of TMC from chitosan using DMC in an ionic liquid. The TMC synthesised was characterised by 1H NMR spectroscopy and a functionally meaningful degree of quaternisation of 9% was demonstrated after a 12-h reaction time.<\/jats:p>","DOI":"10.3390\/molecules24213986","type":"journal-article","created":{"date-parts":[[2019,11,4]],"date-time":"2019-11-04T10:49:07Z","timestamp":1572864547000},"page":"3986","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":19,"title":["Single-Step Methylation of Chitosan Using Dimethyl Carbonate as a Green Methylating Agent"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3612-6735","authenticated-orcid":false,"given":"Ellen B.","family":"Hemming","sequence":"first","affiliation":[{"name":"Laboratory of Advanced Catalysis for Sustainability, School of Chemistry, The University of Sydney, Sydney 2006, Australia"},{"name":"Department of Molecular Sciences and Nanosystems, Universit\u00e0 Ca\u2019 Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anthony F.","family":"Masters","sequence":"additional","affiliation":[{"name":"Laboratory of Advanced Catalysis for Sustainability, School of Chemistry, The University of Sydney, Sydney 2006, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4544-8709","authenticated-orcid":false,"given":"Alvise","family":"Perosa","sequence":"additional","affiliation":[{"name":"Department of Molecular Sciences and Nanosystems, Universit\u00e0 Ca\u2019 Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9986-2393","authenticated-orcid":false,"given":"Maurizio","family":"Selva","sequence":"additional","affiliation":[{"name":"Department of Molecular Sciences and Nanosystems, Universit\u00e0 Ca\u2019 Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thomas","family":"Maschmeyer","sequence":"additional","affiliation":[{"name":"Laboratory of Advanced Catalysis for Sustainability, School of Chemistry, The University of Sydney, Sydney 2006, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,11,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"603","DOI":"10.1016\/j.progpolymsci.2006.06.001","article-title":"Chitin and chitosan: Properties and applications","volume":"31","author":"Rinaudo","year":"2006","journal-title":"Prog. 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