@article{BorovaSchluttNickeletal.2022, author = {Borova, Solomiia and Schlutt, Christine and Nickel, Joachim and Luxenhofer, Robert}, title = {A Transient Initiator for Polypeptoids Postpolymerization α-Functionalization via Activation of a Thioester Group}, series = {Macromolecular Chemistry and Physics}, volume = {223}, journal = {Macromolecular Chemistry and Physics}, number = {3}, doi = {10.1002/macp.202100331}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-257587}, year = {2022}, abstract = {Here, a postpolymerization modification method for an α-terminal functionalized poly-(N-methyl-glycine), also known as polysarcosine, is introduced. 4-(Methylthio)phenyl piperidine-4-carboxylate as an initiator for the ring-opening polymerization of N-methyl-glycine-N-carboxyanhydride followed by oxidation of the thioester group to yield an α-terminal reactive 4-(methylsulfonyl)phenyl piperidine-4-carboxylate polymer is utilized. This represents an activated carboxylic acid terminus, allowing straightforward modification with nucleophiles under mild reaction conditions and provides the possibility to introduce a wide variety of nucleophiles as exemplified using small molecules, fluorescent dyes, and model proteins. The new initiator yielded polymers with well-defined molar mass, low dispersity, and high end-group fidelity, as observed by gel permeation chromatography, nuclear magnetic resonance spectroscopy, and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy. The introduced method can be of great interest for bioconjugation, but requires optimization, especially for protein conjugation.}, language = {en} }