Heterogeneous “Organoclick” Derivatization of Polysaccharides: Photochemical Thiol‐ene Click Modification of Solid Cellulose

Abstract

A simple and direct method for derivatization of solid polysaccharides is presented. The novel methodology is based on the combination of organic acid-catalyzed esterification or etherification and photochemical thiol-ene click derivatization of a heterogeneous polysaccharide. The solid cellulose was "organoclick" modified with aryl, alkyl and polyester groups, respectively. The modification allows for a highly modular and metal free surface modification of solid polysaccharides.

Graft copolymers of hydroxyethyl cellulose by a ‘grafting to’ method:15N labelling as a powerful characterisation tool in ‘click’ polymer chemistry

“…The "grafting to" approach involves the chemical conjugation of a pre-prepared polymer to the cellulose backbone. The conjugation is possible through the presence on each polymer of complementary functional groups which undergo efficient coupling reactions such as thiol-ene 20 , hetero-Diels-Alder 21,22 or copper catalysed azide-alkyne cycloaddition (CuAAC) [23][24][25] . Graft copolymerisation of cellulosic derivatives has mainly been conducted by the "grafting from" method using a cellulosic macro-initiator 26 .…”

Surface functionalization of nanofibrillated cellulose using click-chemistry approach in aqueous media

“…The copper-catalyzed azidealkyne cycloaddition (CuAAC) is one of the most used ''click''-reaction employed in polymer synthesis, offering extensive possibilities to tailor polymer properties Sachsenhofer 2007, 2008;Fournier et al 2007;Meldal 2008;Rostovtsev et al 2002;Tornoe et al 2002). Click-chemistry has also gained attention in the modification of polysaccharides and several articles on the topic can be found (Bernard et al 2008;De Geest et al 2008a, b;Hafrén et al 2006;Hasegawa et al 2006;Koschella et al 2010;Krouit et al 2008;Liebert et al 2006;Schatz et al 2009;Tankam et al 2007;Zhang et al 2009;Zhao et al 2010).…”

Tailor-made functional surfaces based on cellulose-derived materials

“…In the graft onto approach, bioactive molecules or polymers are coupled to the hydroxyl, carboxylic acid, or other functional groups on cellulose surfaces via covalent bond formation. Commonly used graft onto chemistries include azide-alkyne cycloaddition (Krouit et al 2008;Pahimanolis et al 2011), thiol-ene coupling (Tingaut et al 2011;Zhao et al 2010), c o u p l i n g r e a c t i o n s a c t i v a t e d b y 1 -e t h y l -3 -( 3 -dimethylaminopropyl)carbodiimid (EDC) and Nhydroxysuccinimide (NHS) (Arola et al 2012;Orelma et al 2012a;Orelma et al 2012b), oxime ligation (Uth et al 2014), bifunctional reagent-mediated crosslinking (e.g., diisothiocyanate (Araújo et al 2012) and divinyl sulfone (Sannino et al 2003;Yu et al 2012)), Diels-Alder cycloaddition (Tischer et al 2012), photo-induced crosslinking Dietrich et al 2012), and so on. In the graft from approach, initiators are immobilized onto cellulose Scheme 1 Overview of the preparation of functional surfaces using cellulose-based materials surfaces and monomers are polymerized directly from the cellulose surfaces via surface-initiated polymerizations (i.e., atom transfer radical polymerization (ATRP)) Nystrom et al 2006;Qiu et al 2013), reversible addition-fragmentation transfer polymerization (RAFT) , ring-opening polymerization (ROP) (Boujemaoui et al 2012;Goffin et al 2011), and ringopening metathesis polymerization (ROMP) .…”