RAFT polymerization and thio‐bromo substitution: An efficient way towards well‐defined glycopolymers. Issue 21 (8th August 2017)

• Record Type: Journal Article
• Authors: Pröhl, Michael; Englert, Christoph; Gottschaldt, Michael; Brendel, Johannes C.; Schubert, Ulrich S.
• Is Part Of: Journal of polymer science. Volume 55:Issue 21(2017)
• Page Start: 3617
• Page End: 3626
• Publication Date: 2017-08-08
• Subjects: carbohydrates -- glycosylation -- lectins -- nucleophilic substitution -- polymers -- postmodification -- RAFT; 547
• DOI: 10.1002/pola.28745
• Languages: English
• ISSNs: 0887-624X

Abstract

ABSTRACT: Despite an increasing effort to design well‐defined glycopolymers, the convenient synthesis of polymers with higher DPs (>100) and without tedious protection and deprotection steps remains a challenge. Combining the reversible addition fragmentation transfer (RAFT) polymerization and the efficient substitution of primary bromo groups by thiols, we were able to synthesize a set of well‐defined glycopolymers with DPs of up to 115. With the polymerization of the highly reactive monomer (2‐bromoethyl)‐acrylate polymers with low dispersities were obtained that could efficiently be functionalized with various sugar thiol(ate)s. In particular, derivatives ofd ‐glucose, d ‐galactose, andd ‐mannose gave excellent degrees of functionalization close to quantitative conversion using only a slight excess of the thiol. This atom efficient synthesis can even be applied for copolymers with acid or base labile components due to the use of unprotected sugar moieties and, hence, the lack of further deprotection steps. Binding studies with the lectin concanavalin A and the subsequent competition studies with α‐d ‐methyl‐mannopyranose (αMeMan) proved the effective binding of these derivatives and revealed a DP‐ and carbohydrate‐dependent clustering and dissolution. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2017, 55, 3617–3626 Abstract : This research presents an effective and easy post‐glycosylation procedure. A set of poly(bromoethyl acrylate)s with DPs up to 115 was obtained by RAFT polymerization technique and was almost quantitatively post‐functionalized in SN 2 reactions with various aldoses—in detaild ‐glucose, d ‐galactose, andd ‐mannose. Turbidity studies with the binding lectin Con A and the competitor α‐d ‐methyl‐mannopyranose revealed sugar‐ and length‐dependent effects.