Comparing different initiator types for Cu‐mediated polymerization has shown that thioester‐based initiators can be an excellent alternative that allow further conjugation via native chemical ligation, as exemplified on a star polymer using l‐cysteine methyl ester hydrochloride. Abstract The synthesis of a new class of Cu‐mediated polymerization initiators with thioester functionality is demonstrated and their polymerization kinetics via single‐electron transfer living radical polymerization...
by Suzan Aksakal, Resat Aksakal, Caglar Remzi Becer via Macromolecular Rapid Communications
Macromolecular Rapid Communications Transformation of Thioester‐Initiated Star Polymers into Linear Arms via Native Chemical Ligation
Comparing different initiator types for Cu‐mediated polymerization has shown that thioester‐based initiators can be an excellent alternative that allow further conjugation via native chemical ligation, as exemplified on a star polymer using l‐cysteine methyl ester hydrochloride.
Abstract
The synthesis of a new class of Cu‐mediated polymerization initiators with thioester functionality is demonstrated and their polymerization kinetics via single‐electron transfer living radical polymerization is reported. From periodic sampling, it is found that thioester‐ or ester‐based initiators can be employed interchangeably, resulting in very similar polymerization rates. Furthermore, a multifunctional thioester initiator is employed for the preparation of a well‐defined four‐arm star‐shaped polymer. It is further shown that the full dissociation of the star polymer into linear arms via native chemical ligation can easily be followed via size exclusion chromatography, as a result of the change in hydrodynamic volume. Finally, the obtained linear polymers are characterized via matrix‐assisted laser desorption/ionization–time of flight mass spectrometry and found to be in good agreement with the expected molecular weight distribution that confirms the successful transformation.
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