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Search for "polymer" in Full Text gives 615 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Recent developments and trends in the iron- and cobalt-catalyzed Sonogashira reactions
Beilstein J. Org. Chem. 2022, 18, 262–285, doi:10.3762/bjoc.18.31
- polymer) (Co@imine-POP) has been synthesized by immobilizing cobalt onto a nitrogen-rich porous organic polymer (Scheme 20) [35]. Using scanning electron microscopy, the surface morphology of the catalyst was evaluated. Nowadays, covalent organic frameworks (COF) were found to be a suitable support in
- reaction (Scheme 31). Non-nanoparticle-based protocols Nanoparticles are materials with sizes around nanometer scales. The used nanoparticles are environmentally friendly magnetic cross-linked chitosan fibers which is a natural polysaccharide polymer. In this regard the use of such polymers is promising
Green synthesis of C5–C6-unsubstituted 1,4-DHP scaffolds using an efficient Ni–chitosan nanocatalyst under ultrasonic conditions
Beilstein J. Org. Chem. 2022, 18, 133–142, doi:10.3762/bjoc.18.14
- . Chitosan is one of the most abundant bio-based polymers in nature [9]. It is the N-deacetylated form of chitin found in industrial waste [10]. Chitosan is a broadly used natural polymer because of properties such as biocompatibility, low cost, and nontoxicity. It has diverse applications, such as drug
Study on the interactions between melamine-cored Schiff bases with cucurbit[n]urils of different sizes and its application in detecting silver ions
Beilstein J. Org. Chem. 2021, 17, 2950–2958, doi:10.3762/bjoc.17.204
- supermolecule polymer with TBT due to its larger cavity. Since Q[7] and TBT form a host–guest complex, the carboxyl group at the end of TBT and the carbonyl group of the Q[7] still have a strong ability to coordinate with metals. Therefore, Q[7]-TBT is selected for the detection of silver ions (Ag+) [32][33
Polymer chemistry: fundamentals and applications
Beilstein J. Org. Chem. 2021, 17, 2922–2923, doi:10.3762/bjoc.17.200
- Bernhard V. K. J. Schmidt School of Chemistry, University of Glasgow, G12 8QQ Glasgow, UK 10.3762/bjoc.17.200 Keywords: polymer chemistry; Ever since the introduction of the term macromolecule and the early days of polymer science [1], organic chemistry and polymer chemistry have been closely
- related [2]. It only seems to be a logical step to give room for a thematic issue on polymer chemistry in the Beilstein Journal of Organic Chemistry. The connection between organic and polymer chemistry has been highlighted frequently [3][4], up to the point where one can talk about macroorganic chemistry
- , where oligomers bring molecular precision from organic chemistry together with materials properties from polymer chemistry [5]. Especially in the challenge of transformation to a more sustainable polymer science, organic chemistry can give significant support in the development of greener polymer
A two-phase bromination process using tetraalkylammonium hydroxide for the practical synthesis of α-bromolactones from lactones
Beilstein J. Org. Chem. 2021, 17, 2906–2914, doi:10.3762/bjoc.17.198
- polymerization (ATRP) reactions and functional polymer synthesis [29][30][31][32][33][34]. Although α-bromo-γ-butyrolactone, which is a five-membered lactone, is easily accessible from the five-membered lactone by some bromination methods [35][36], the bromination method for the six-membered lactone, δ
Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode
Beilstein J. Org. Chem. 2021, 17, 2894–2905, doi:10.3762/bjoc.17.197
- other high molecular weight emitters can show at least some degree of orientation in solution-processed films. For instance, Senes et al. [23][24]. showed that the OPVn series of polymers exhibited higher horizontal orientation by increasing the length of the polymer chain, and by extension the molecule
Adjusting the length of supramolecular polymer bottlebrushes by top-down approaches
Beilstein J. Org. Chem. 2021, 17, 2621–2628, doi:10.3762/bjoc.17.175
- University Jena, Philosophenweg 7, 07743 Jena, Germany 10.3762/bjoc.17.175 Abstract Controlling the length of one-dimensional (1D) polymer nanostructures remains a key challenge on the way toward the applications of these structures. Here, we demonstrate that top-down processing facilitates a
- straightforward adjustment of the length of polyethylene oxide (PEO)-based supramolecular polymer bottlebrushes (SPBs) in aqueous solutions. These cylindrical structures self-assemble via directional hydrogen bonds formed by benzenetrisurea (BTU) or benzenetrispeptide (BTP) motifs located within the hydrophobic
- methods represent an easily implementable technique toward 1D polymer nanostructures with an adjustable length in the range of interest for perspective biomedical applications. Keywords: distribution; dual centrifugation; filomicelles; self-assembly; ultrasonication; Introduction Cylindrical polymer
Cryogels: recent applications in 3D-bioprinting, injectable cryogels, drug delivery, and wound healing
Beilstein J. Org. Chem. 2021, 17, 2553–2569, doi:10.3762/bjoc.17.171
- ; Introduction Gels can be defined as polymer networks that are expanded throughout their whole volume by a fluid. In the case of hydrogels, the network component is a hydrophilic polymer, and the swelling agent is water [1]. However, their lack of interconnected macropores and elasticity, required properties
- solution is then cooled to below the freezing point of water, whereby ice crystals form. Importantly, here the solvent (water) solidifies (freezes) and forms solid solvent porogens within the structure allowing the polymer network to form around these crystals, templating the porous structure of the final
- properties Cryogels are macroporous hydrogels with interconnected porosity, with high swelling capacities and large surface areas. Ultimately, many of the final cryogel properties are dependent on the choice of polymer/monomer composition used. However, other factors such as crosslinking, pore size, wall
Silica gel and microwave-promoted synthesis of dihydropyrrolizines and tetrahydroindolizines from enaminones
Beilstein J. Org. Chem. 2021, 17, 2543–2552, doi:10.3762/bjoc.17.170
- Robin Klintworth Garreth L. Morgans Stefania M. Scalzullo Charles B. de Koning Willem A. L. van Otterlo Joseph P. Michael Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, PO Wits 2050, Johannesburg, South Africa Department of Chemistry and Polymer Science
In-depth characterization of self-healing polymers based on π–π interactions
Beilstein J. Org. Chem. 2021, 17, 2496–2504, doi:10.3762/bjoc.17.166
- of Photonic Technology (IPHT), e. V. Jena, Albert-Einstein-Straße 9, 07745 Jena, Germany 10.3762/bjoc.17.166 Abstract The self-healing behavior of two supramolecular polymers based on π–π-interactions featuring different polymer backbones is presented. For this purpose, these polymers were
- behavior as well as the in-depth characterization of the molecular behavior and the macroscopic properties, which reveals new insights into the self-healing materials based on π–π interactions. Results and Discussion Polymer synthesis For the synthesis of supramolecular polymers based on π-π interactions a
- molar mass of approximately 2000 g/mol resulting in polymer P1. In order to study the influence of the polymer backbone on the material’s properties, the diamine containing polymer was exchanged to a triblock copolymer of poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol
Exfoliated black phosphorous-mediated CuAAC chemistry for organic and macromolecular synthesis under white LED and near-IR irradiation
Beilstein J. Org. Chem. 2021, 17, 2477–2487, doi:10.3762/bjoc.17.164
- , Turkey King Abdulaziz University, Faculty of Science, Chemistry Department, 21589 Jeddah, Saudi Arabia 10.3762/bjoc.17.164 Abstract The development of long-wavelength photoinduced copper-catalyzed azide–alkyne click (CuAAC) reaction routes is attractive for organic and polymer chemistry. In this study
- has set a milestone as a new and effective method for the synthesis of macromolecules [11]. Initiation of this reaction photocatalytically provides many advantages for the synthetic methodologies including bioconjugation, labeling, surface functionalization, dendrimer synthesis, polymer synthesis, and
- polymer modification by adding spatial and temporal control [12][13]. In recent years, heterogeneous photocatalysts have been performed in many photosynthetic reactions since they provide a more reasonable and easy way to synthesize the targeted products compared to the classical homogenous photocatalysts
Post-functionalization of drug-loaded nanoparticles prepared by polymerization-induced self-assembly (PISA) with mitochondria targeting ligands
Beilstein J. Org. Chem. 2021, 17, 2302–2314, doi:10.3762/bjoc.17.148
- -((phenylcarbonothioyl)thio)pentanoic acid, but it was modified with ethylene glycol. During the polymerization of the water-soluble polymers, fluorescein O-methacrylate was added at a ratio of CTA to fluorescent monomer of 1:0.3. This means more that three out of ten polymer chains will be labelled, which is sufficient
- for cell work. The water-soluble polymer was then chain-extended via PISA using MMA at a various feed ratio of MMA and RAFT agent using earlier procedures [42], resulting in nanoparticles with hydroxy functionalities located on the surface. In earlier studies it was observed that shorter MPC blocks
- ppm was used. As the polymer has 63 PEGMEMA repeating units, the intensity of this peak is 189, which should be equivalent to the 15 aromatic peaks of TPP. This signal overlaps with 7 × 4 aromatic peaks belonging to PENAO. Care needs to be taken here as this is also the region of the aromatic group of
Chemical syntheses and salient features of azulene-containing homo- and copolymers
Beilstein J. Org. Chem. 2021, 17, 2164–2185, doi:10.3762/bjoc.17.139
- photovoltaic (PV) cells. Since azulene has a fused five and seven-membered ring structure, it can be incorporated onto the polymer backbone through either of these rings or by involving both the rings. These azulene-connection patterns can influence the properties of the resulting polymers and the chemical
- chemical and electrochemical means. Through electrochemical methods, only the five-membered rings can be incorporated onto the polymer backbone, and often the polymers produced are insoluble [17]. On the other hand, chemical synthesis provides an avenue to synthesize soluble polymers where azulene can be
- incorporated into the backbone through either of the rings or by involving both the rings. These substitution patterns can influence the property of the resulting polymer. However, to achieve the synthesis of such homo- and copolymers, suitably tailor-made azulene monomers with specific substitution patterns
Constrained thermoresponsive polymers – new insights into fundamentals and applications
Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138
- , have been intensively studied in solution. For the application of such polymers in novel sensors, drug delivery systems or as multifunctional coatings, they typically have to be transferred into specific arrangements, such as micelles, polymer films or grafted nanoparticles. However, it turns out that
- the thermodynamic concept for the phase transition of free polymer chains fails, when thermoresponsive polymers are assembled into such sterically confined architectures. Whereas many published studies focus on synthetic aspects as well as individual applications of thermoresponsive polymers, the
- representative. In contrast, for polymer arrangements with an upper critical solution temperature (UCST), there is only limited knowledge about preparation, application and precise physical understanding of the phase transition. This review article provides an overview about the current knowledge of
An initiator- and catalyst-free hydrogel coating process for 3D printed medical-grade poly(ε-caprolactone)
Beilstein J. Org. Chem. 2021, 17, 2095–2101, doi:10.3762/bjoc.17.136
- Jochen Loblein Thomas Lorson Miriam Komma Tobias Kielholz Maike Windbergs Paul D. Dalton Robert Luxenhofer Polymer Functional Materials, Chair for Advanced Materials Synthesis, Institute for Functional Materials and Biofabrication, Department of Chemistry and Pharmacy, Julius-Maximilians
- nm to 10 µm) and micro-scale filaments onto a collector with repeat fiber deposition to build up a micro-scale 3D object, with build heights in the range of several millimeters [9][10][11]. In MEW, the polymer jet is electrostatically drawn from a nozzle, resulting in a considerable reduction of the
- mechanical properties, cytocompatibility, biodegradability, and good printing properties [8][14][15], it is a hydrophobic polymer and immersion into fluids can result in air bubble capture within the scaffold structure, biofouling and non-specific cell interactions [16]. Protein adsorption and denaturation
Towards new NIR dyes for free radical photopolymerization processes
Beilstein J. Org. Chem. 2021, 17, 2067–2076, doi:10.3762/bjoc.17.133
- abilities were found for some reported dyes when used in combination with iodonium salt and amine. Markedly, photothermal effects with a huge heater behavior were also observed for different NIR dye structures. Interestingly, the synthesis of interpenetrating polymer networks (IPNs, e.g., for the
- filled samples can be potentially used for composite materials and/or adhesives. Both photochemical and photothermal NIR approaches were proposed to initiate polymerization, e.g., for free-radical processes, interpenetrating polymer network (IPN) synthesis, or photopolyaddition reactions [3][4][6][7][8
- -component systems can also be used for the preparation of IPNs through the polymerization of acrylate/epoxy monomer blends (3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate from Allnex was used as benchmark epoxy monomer) [20]. The formation of IPNs can be highly worthwhile to reach better polymer
Progress and challenges in the synthesis of sequence controlled polysaccharides
Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129
- be quite challenging to prepare. Moreover, problems can occur during the removal of the PGs, since partially deprotected compounds can generate insoluble aggregates [24]. Incomplete deprotection and residual PGs can largely affect the properties of the obtained polymer. Chemical synthesis provides
- methodologies or post-extraction modifications are not discussed. Review Glucose-based polysaccharides Cellulose Cellulose is a polymer consisting of glucose units connected by β(1–4) glycosidic bonds. It is mainly found in two allomorphs – Cellulose I (natural) and Cellulose II (synthetic) – that differ in the
- achieved by ROP of 3,6-dibenzyl-protected 4 catalyzed by Ph3CBF4 [83]. The protected polymer 5 was obtained in 2 h in 62% yield and an average DP of 19.3. The benzyl (Bn) group seems to be essential for the selective transformation [84]. Several derivatives were prepared in a similar fashion (Scheme 1B
Natural products in the predatory defence of the filamentous fungal pathogen Aspergillus fumigatus
Beilstein J. Org. Chem. 2021, 17, 1814–1827, doi:10.3762/bjoc.17.124
- -melanin synthesis completely which leads to white spores [45]. DHN-melanin is a heterogeneous polymer, as such it does not have a unique structure. Its insolubility aggravates any structural analyses of the deciphering of repetitive motives. However, there were studies doing either computational
Development of N-F fluorinating agents and their fluorinations: Historical perspective
Beilstein J. Org. Chem. 2021, 17, 1752–1813, doi:10.3762/bjoc.17.123
- shows 31 examples and their methods of preparation. Umemoto and co-worker also reported the synthesis of a polymer version, poly(vinyl-N-fluoropyridinium salts) of these reagents [36]. The reactivities of many N-fluoropyridinium salts were examined [32] and mainly five kinds of N-fluoropyridinium salts
- acid, or its metal salt in acetonitrile or as a 50:1 mixture of acetonitrile/formic acid at −40 to 0 °C. The yields were good to excellent [86] (Figure 7). The trimer 24-3 and polymer homologues 24-4 were also prepared. The N,N’-difluorobipyridinium salts are stable and generally furnished non
A systems-based framework to computationally describe putative transcription factors and signaling pathways regulating glycan biosynthesis
Beilstein J. Org. Chem. 2021, 17, 1712–1724, doi:10.3762/bjoc.17.119
- for the addition of GalNAc to glucuronic acid to increase chondroitin polymer length, CHST3, CHST11, and UST are involved in the sulfation of GalNAc and iduronic acid, and DSEL is the epimerase which converts glucuronic acid to iduronic acid in CS/DS chains. MECP2 disproportionately regulates heparan
Electron-rich triarylphosphines as nucleophilic catalysts for oxa-Michael reactions
Beilstein J. Org. Chem. 2021, 17, 1689–1697, doi:10.3762/bjoc.17.117
- mixture was dissolved in dichloromethane and precipitated from diethyl ether resulting in about 50% polymer yield featuring Mn values of 1500–1800 g/mol [30]. Next, the oxidation stability of the catalysts was tested. For this purpose, the three different phosphines were exposed to air for 14 d in dark
- from MZ-Gel SD plus, 500 A and 100 A, linear 5 µ; UV detector (SPD-20A) and RI detector (RID-20A)) using THF as eluent. Poly(styrene) standards in the range of 350 to 17800 g/mol purchased from Polymer Standard Service were used for calibration. Computational details All calculations were run with the
Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications
Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116
- [1]. Even with the additional lysine, the solubility of PNA decreases as the polymer length increases. PNA solubility in the HEPES buffer at pH 7.3 and 37 °C is estimated to be in the 0.1–0.5 mM range [12][13]. The hydrophobic nature and lack of electrostatic repulsion of the PNA backbone favors
A recent overview on the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles
Beilstein J. Org. Chem. 2021, 17, 1600–1628, doi:10.3762/bjoc.17.114
- decrease in the yield [47]. Some research groups have utilized strain-promoted azide–alkyne cycloaddition reactions (SPAAC) on side chains to afford polymer-based prodrugs. Generally, a range of key strained cyclooctyne derivatives 52 could be reacted with aliphatic azides 51 via this strategy to give
- fully decorated triazoles 53 (Scheme 18a). A research group reported a novel polymer 56 functionalized by doxorubicin (DOX). To produce this prodrug, cyclooctyne-derivatized doxorubicin 55 was grafted on an azide-functionalized polymer 54. In the final step of the construction of this prodrug, the
- after the support of DOX molecules on the polymer prodrug, which resulted in reduced side effects (Scheme 18b) [48][49]. Cu-catalyzed synthesis of fully decorated triazoles The Cu-catalyzed regioselective cyclization of alkynes 57 and azides 58, followed by coupling with propargylic carbonates 59
Methodologies for the synthesis of quaternary carbon centers via hydroalkylation of unactivated olefins: twenty years of advances
Beilstein J. Org. Chem. 2021, 17, 1565–1590, doi:10.3762/bjoc.17.112
- ., styrene derivatives [17]) that produce hundreds of tons for polymer synthesis. The goal of this review is to demonstrate the utility of olefins as starting materials in the synthesis of all-carbon quaternary centers through hydroalkylation reactions. Only the hydroalkylation of unactivated olefins as
Recent advances in the application of isoindigo derivatives in materials chemistry
Beilstein J. Org. Chem. 2021, 17, 1533–1564, doi:10.3762/bjoc.17.111
- of functional materials are analyzed and summarized. These bisheterocycles can be used in the creation of organic solar cells, sensors, lithium ion batteries as well as in OFET and OLED technologies. The potentials of the use of polymer structures based on isoindigo as photoactive component in the
- compound 9c led to a decrease in the efficiency to 2.82% [22]. Perylene diimide-derived isoindigo derivative 10 was used as an acceptor in the creation of a nonfullerene OSC with thiophene polymer 11 as a donor component (Scheme 8). The PCE value of such a device turned out to be 2.6%. Cho et al
- popular and most studied direction in the creation of OSCs is the use of polymer structures containing an isoindigo fragment in a monomer unit associated with a different number of thiophene substituents (Scheme 12). By the example of one of the simplest representatives of this type of polymers, a
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