Multigram chromatography-free synthesis of octa(ethylene glycol) p-toluenesulfonate

Wawro, Adam M.; Muraoka, Takahiro; Kato, Maho

doi:10.1039/c6qo00398b

Cited by 24 publications

(31 citation statements)

References 9 publications

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“…For the synthesis of 1 , it is notable that due to the use of the slow addition technique, we were able to keep the ditritylated side product 17 at a minimum while using only five equivalents (PEG) 4 . In contrast, in some previous reports concerning the synthesis of DMTrO(PEG) 4 and similar compounds, 10 equivalents (PEG) 4 were used and the amount of symmetric side product could be higher ,…”

Section: Resultsmentioning

confidence: 85%

“…The cycle is then repeated to give 6 . At this stage, the PEG is asymmetric, which is highly desirable in most applications but more challenging to make using other methods . However, if it were cleaved from the solid support, it would become symmetrical.…”

Section: Resultsmentioning

confidence: 99%

“…ESI‐MS analysis using Method A showed 77 % (PEG) 20 and 23 % (PEG) 16 (Figure S7). Although these results were significant because the longer PEGs could be easily separated from shorter ones using techniques involving tagging followed by chromatography, polymerization or extraction, such studies had not been pursued. Instead, it came to our attention that the synthesis of pure (PEG) 12 and its asymmetric derivatives using a convenient method without any chromatography is highly significant.…”

Section: Resultsmentioning

confidence: 99%

“…In contrast, using solution phase synthesis, the monomers have to be purified with chromatography and impurities such as 17 and 18 have to be removed, because even though they are inert during coupling, they will contaminate the product and may become more difficult to remove. One exception is the method reported by Kinbara group ,. The authors elegantly demonstrated the synthesis of monodisperse PEGs without chromatography.…”

Section: Resultsmentioning

confidence: 99%

“…8–40 ethylene glycol units) synthesis, one of the major problems is the need of multiple column chromatography to purify monomers, intermediates and the final product. This problem has severely impeded the practical use of stepwise synthesis for inexpensive large scale monodisperse PEG production ,,…”

Section: Introductionmentioning

confidence: 99%

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Solid Phase Stepwise Synthesis of Polyethylene Glycols

Khanal

Fang

2017

Chemistry A European J

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Polyethylene glycol (PEG) and derivatives with eight and twelve ethylene glycol units were synthesized by stepwise addition of tetraethylene glycol monomers on a polystyrene solid support. The monomer contains a tosyl group at one end and a dimethoxytrityl group at the other. The Wang resin, which contains the 4-benzyloxy benzyl alcohol function, was used as the support. The synthetic cycle consists of deprotonation, Williamson ether formation (coupling), and detritylation. Cleavage of PEGs from solid support was achieved with trifluoroacetic acid. The synthesis including monomer synthesis was entirely chromatography-free. PEG products including those with different functionalities at the two terminals were obtained in high yields. The products were analyzed with ESI and MALDI-TOF MS and were found close to monodispersity.

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Section: Resultsmentioning

confidence: 85%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Solid Phase Stepwise Synthesis of Polyethylene Glycols

Khanal

Fang

2017

Chemistry A European J

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Imidazolinium‐based Multiblock Amphiphile as Transmembrane Anion Transporter

Mori

Sato

Ekimoto

et al. 2020

Chemistry An Asian Journal

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Transmembrane anion transport is an important biological process in maintaining cellular functions. Thus, synthetic anion transporters are widely developed for their biological applications. Imidazolinium was introduced as anion recognition site to a multiblock amphiphilic structure that consists of octa(ethylene glycol) and aromatic units. Ion transport assay using halide-sensitive lucigenin and pHsensitive 8-hydroxypyrene-1,3,6-trisulfonate (HPTS) revealed that imidazolinium-based multiblock amphiphile (IMA) transports anions and showed high selectivity for nitrate, which plays crucial roles in many biological events. Temperaturedependent ion transport assay using 1,2-dipalmitoyl-snglycero-3-phosphocholine (DPPC) indicated that IMA works as a mobile carrier. 1 H NMR titration experiments indicated that the C2 proton of the imidazolinium ring recognizes anions via a (CÀ H) + •••X À hydrogen bond. Furthermore, allatom molecular dynamics simulations revealed a dynamic feature of IMA within the membranes during ion transportation.

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Uniform Macromolecules: Performance of Common Analytic Instruments in Detecting Impurities

Bohn,

Frölich,

Hahn

et al. 2024

Macro Chemistry & Physics

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Inspired by the highly defined structure of biomacromolecules, e.g. deoxyribonuleic acid (DNA) and proteins, the preparation and characterization of sequence‐defined and uniform macromolecules gained interest in polymer chemistry. With the development of various synthetic approaches, the challenge of analyzing and confirming the uniform structures emerged. Here, the investigation on the performance of common analytical instruments for the characterization of uniform macromolecules regarding impurities of ±1 in degree of oligomerization is presented. Thus, different mixtures containing oligomers differing in one repeating unit of oligo(ethylene glycol)s (OEG)s, oligo(phenylene ethynylene)s (OPE)s, and Passerini oligomers, respectively, are synthesized, and analyzed by proton nuclear magnetic resonance spectroscopy (1H NMR), size exclusion chromatography (SEC), and high‐resolution electrospray ionization mass spectrometry (HR‐ESI‐MS). These results demonstrate the indispensability of a careful characterization using more than one technique for determining uniformity. In particular, the obtained SEC results show that it is a powerful tool for purity determination of low molecular weight oligomers.

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Multigram chromatography-free synthesis of octa(ethylene glycol) p-toluenesulfonate

Abstract: A detailed synthetic procedure for the chromatography-free synthesis of octa(ethylene glycol) p-toluenesulfonate is reported.

Cited by 24 publications

References 9 publications

Solid Phase Stepwise Synthesis of Polyethylene Glycols

Solid Phase Stepwise Synthesis of Polyethylene Glycols

Imidazolinium‐based Multiblock Amphiphile as Transmembrane Anion Transporter

Uniform Macromolecules: Performance of Common Analytic Instruments in Detecting Impurities

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