Thioester functional polymers

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The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/marc.201800650. ChemistryBefore moving to the recent advances within the last 5 years in the diverse applications of sulfur chemistry in polymer and Sulfur-Containing PolymersSulfur and its functional groups are major players in an area of exciting research taking place in modern polymer and materials science, both in academia and industry. In fact, manifold sulfur-based reactions that are both exceptionally versatile as well as tremendously useful have been implemented, and further utilized for the design and preparation of polymeric materials that lead to a plethora of applications ranging from medicine to optics and nanotechnology to separation science. Hence, within this review, an overview of strategies and developments used over the last 5 years to reinforce the importance of the sulfur functional group in modern polymer and materials science is presented. In particular, many important references in the primary literature of sulfur chemistry are referred to, including thiol-ene, thiol-yne, thiol-Michael addition, disulfide cross-linking, and thiol-disulfide exchange, among others, by explaining and illustrating the important principles. Last but not least, the grand aim to underpin the importance of sulfur in modern polymer and materials science is achieved by presenting selected examples in diverse fields and postulating the respective potential for real-world applications. he is now a full professor at KIT.sulfur atoms, and tetraphenylethene-bearing di(alkyl bromide) (Scheme 3). The yield of the polymerization was dependent on the di(alkyl bromide) monomer; the longer spacer between the aromatic moiety and the reactive bromide end groups Scheme 1. The discussion henceforth focuses on the synthesis of polymers possessing the depicted sulfur functional groups. Scheme 2.Representative examples of polythioethers prepared via A) the nucleophilic substitution reaction between an electrophilic dihalide with nucleophilic derivatives of dithiols under alkaline conditions; B) the thiol-ene/yne addition reaction between AA and BB type monomers (i.e., dithiols and dienes/diynes); and C) radical or ionic ring-opening of sulfurcontaining strained rings.Scheme 3. The thiol-bromo polymerization of conformationally fixed monomers to provide multifunctional polymers. [19] Macromol. Rapid Commun. 2019, 40, 1800650 Scheme 4. The regioselective selective nucleophilic aromatic substitution between thiol and fluorinated aromatic compounds, the para-fluorothiol reaction (PFTR).Scheme 5. Synthesis of a linear polymer via PFTR-reaction. [21]

Section: Chemistrymentioning

confidence: 99%

Sulfur Chemistry in Polymer and Materials Science

Mutlu

Ceper

et al. 2018

232

220

“…Thioester functional polymers can mainly be obtained by employing thioester‐containing monomers (e.g., thioacrylates, thiolactone), their generation during the polymerization process (e.g., polythioesters), or by using thioester‐containing chain transfer agents/initiators depending on the employed polymerization technique . In metal‐mediated polymerizations such as atom transfer radical polymerization (ATRP) or single‐electron transfer living radical polymerization (SET‐LRP), mostly ester‐based initiators are used due to their easy synthesis, but more importantly due to their compatibility with a wide range of monomers, which is determined by efficiency of the initiator.…”

Section: Methodsmentioning

confidence: 99%

“…

process (e.g., polythioesters), or by using thioester-containing chain transfer agents/ initiators depending on the employed polymerization technique. [6][7][8][9][10] In metalmediated poly merizations such as atom transfer radical polymerization (ATRP) or single-electron transfer living radical polymerization (SET-LRP), mostly esterbased initiators are used due to their easy synthesis, but more importantly due to their compatibility with a wide range of monomers, which is determined by efficiency of the initiator.The employed initiators in the literature have three main structural features that effect the efficiency, namely i) the initiator halogen, ii) the R-groups that substitute the α-carbon, and iii) the nature of the neighboring group (Scheme 1). Two of the most widely used ester initiators bearing a bromine chain end are methyl bromoproprionate and ethyl α-bromoisobutyrate (EBiB), which are mainly used to polymerize (meth)acrylates and acrylonitrile monomers.

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mentioning

confidence: 99%

Transformation of Thioester‐Initiated Star Polymers into Linear Arms via Native Chemical Ligation

Aksakal

Becer

2019

Self Cite

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.

“…It also reduces the length of the side chains, thus limiting their flexibility which could be potentially important for applications such as cell interaction. Thus, a new sequence‐defined protocol was developed in collaboration with Becer and co‐workers, which explored the incorporation of thioacrylates and their modification using primary amines …”

Section: Methodsmentioning

confidence: 99%

Automated Synthesis Protocol of Sequence‐Defined Oligo‐Urethane‐Amides Using Thiolactone Chemistry

Holloway

Mertens

Prez

et al. 2018

An automated, iterative protocol for the synthesis of multifunctional, sequence‐defined oligo‐urethane‐amides using thiolactone chemistry is reported. Here, sequenced functionalization of the backbone is easily introduced using commercially available primary amines. The chemistry is carried out on solid phase using different supports for better optimization of the synthetic protocol and in order to demonstrate the versatility of the approach. This technique is very effective for iterative synthesis and solid‐phase chemistry and enables the exploration of full automation of this approach using a robotic peptide synthesizer. As a result, this automated protocol allows for the synthesis of a sequence‐defined nonamer of high purity.