Synthesis of ω-End Group Functionalized Poly(methyl methacrylate)s via RAFT Polymerization

Abstract

Living" poly(methyl methacrylate) (PMMA), prepared by the RAFT technique, reacted with maleic anhydride to give succinic anhydride-terminated PMMA (SA-PMMA) in very high yield. The ω-terminal anhydride residues react in high yields with primary alcohols, primary amines and aromatic amines. As examples, SA-PMMA reacted with 1H,1H,2H,2H-perfluorodecylamine to give a polymer containing 5.78% of fluorine; with Disperse Orange 3 to give a dye-labeled PMMA; with 9-hydroxymethylanthracene to give a fluorescently labeled PMMA; with norephedrine to give a polymer with a biologically active end group; and with 4,4 0 -diaminophenymethane to give amine-ended PMMA. The latter reacted smoothly with fluorescein isocyanate to give a fluorescently labeled PMMA. In these examples the fraction of polymer chains functionalized were in the range 75-95%. Allowing for the fact the starting PMMAs were up to 96% "living", these loadings correspond to functionalization yields, for the anhydride addition plus the reaction with the nucleophiles, of 81-99%.

A Potential New RAFT - Click Reaction or a Cautionary Note on the Use of Diazomethane to Methylate RAFT-synthesized Polymers

“…Sasso et al [18] reported the diazomethane methylation of a RAFT-synthesized polymer. However, the dithiobenzoate ends had been previously removed by amine treatment and no unexpected reactions were reported.…”

Building nanostructures using RAFT polymerization

“…280 Finally, the addition maleic anhydride or maleimide at the end of the polymerization was proposed to give succinic anhydride or functional terminated polymers in very high yield, respectively. 281,282 The presence of this anhydride group can be exploited to react different alcohols, primary amines and aromatic amines with a very high functionality (75-95%). The polymer can be chain extended using another monomer to introduce mid-chain functionality.…”

RAFT polymerization mediated bioconjugation strategies

“…The thiol-functional polymers could be further modified with thiol-reactive reagents, such as maleic anhydride, 66 for creating highly reactive sites for conjugation with biomolecules. Alternatively, thiol-functional polymers can be used directly for bioconjugations without any further modification.…”

“…When designing R-and Z-groups, amines, thiols, carboxylic acids and ketones/aldehydes, which are the reactive groups of biological molecules, commonly used for bioconjugations, have been considered. 56,66,69,70, Bioconjugation strategies combining click reactions such as azidealkyne cycloadditions and thiol-ene additions with end-group functionalized RAFT polymers have also attracted attention because of high efficiency of such reactions (vide infra).…”