Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• copolymer, benzodithiophene-thiadiazolo-quinoxaline (Qx54), by introducing trifluoromethyl groups to the Qx moiety (Qx55). This strategic modification changed the HOMO and LUMO levels, resulting in a conversion from ambipolar charge transport to n-type charge transport. The polymeric thin-film transistors

• (PTFTs) with Qx54 copolymer showed ambipolar characteristics, while the PTFTs with Qx55 copolymer exhibited only n-type charge transport [57]. Kamble et al. designed and synthesized a series of eight new indolo[2,3-b]naphtho[2,3-f]quinoxaline derivatives (Qx56) by incorporating an electron-accepting

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• by radical unzipping depolymerization under photon or β-irradiation (Scheme 20a). Similarly, poly(olefin sulfone) undergoes depolymerization upon irradiation of light or electron beams [193][194]. It is an alternating copolymer of 1-olefins and SO2, and therefore the decomposition products are mostly

Investigation of cationic ring-opening polymerization of 2-oxazolines in the “green” solvent dihydrolevoglucosenone

• Solomiia Borova and
• Robert Luxenhofer

Beilstein J. Org. Chem. 2023, 19, 217–230, doi:10.3762/bjoc.19.21

• of view [28]. Accordingly, Hoogenboom et al. investigated the CROP of 2-alkyl-2-oxazoline in sulfolane and investigated its effect on monomer distribution and self-assembly of the performed copolymer [30][31][32]. However, the degradability of sulfolane into acidic components, its relatively high

• ). However, again the Mn of the final polymer is lower than expected and shows a relatively wide molar mass distribution (Ð = 1.36). Also, the shape of the SEC trace of the final polymer is not narrow or symmetrical. The resulting block copolymer did not show successful results in the preparation of the drug

• observed after 3 h of reaction) during polymerization at 90 °C, but the final molar mass remains lower than expected with significant bimodality. An attempt at the synthesis of a PEtOx-b-PBuOx-b-PEtOx triblock copolymer yielded again a broad molar mass distribution and a lower molar mass than expected by

Nostochopcerol, a new antibacterial monoacylglycerol from the edible cyanobacterium Nostochopsis lobatus

• Naoya Oku,
• Saki Hayashi,
• Yuji Yamaguchi,
• Hiroyuki Takenaka and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2023, 19, 133–138, doi:10.3762/bjoc.19.13

• responsible constituent, though prone to diffuse during chromatography, was purified with the guidance of antibacterial activity on ODS and Sephadex LH-20 and by reversed-phase HPLC on ODS and styrene-divinylbenzene copolymer to yield 0.7 mg of compound 1 from 113.3 mg of the solvent partition fraction. The

Inline purification in continuous flow synthesis – opportunities and challenges

• Jorge García-Lacuna and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 1720–1740, doi:10.3762/bjoc.18.182

• concentration of less than 1% within four hours, and water-soluble monomers. In addition, the integration of this setup into an inline synthesis step starting from block copolymer solutions, and rhodamine encapsulation produced micelles without affecting the particle size is also demonstrated. The growing

Microelectrode arrays, electrosynthesis, and the optimization of signaling on an inert, stable surface

• Kendra Drayton-White,
• Siyue Liu,
• Yu-Chia Chang,
• Sakashi Uppal and
• Kevin D. Moeller

Beilstein J. Org. Chem. 2022, 18, 1488–1498, doi:10.3762/bjoc.18.156

• can be used to help prevent non-specific binding and minimize biofouling possibilities [18]. While the use of a diblock copolymer coating offers the desired stability advantage, it also rules out the use of both direct methods for conducting synthetic transformations on the array and the direct

• peptides were placed on the array along with a fluorescent dye (LRSC, lissamine rhodamine) that was used to make sure the placement chemistry was working. The array used was coated with the borate ester diblock copolymer (Figure 2), and the peptides were attached to this polymer through a PEG-6 linker in

• diblock copolymer. Binding between the integrin receptor and the RGD peptide on the polymer increased the solubility of the polymer above the associated electrodes and in so doing increased the current associated with the mediator. This change in current relative to the concentration of integrin in

Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons

• Hengjia Liu and
• Guohua Xie

Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83

• optoelectronic properties of a fluorene-based copolymer with an sp2 nitrogen heteroatom via supramolecular coordination [33]. The PL emission in solution showed an obvious red-shifted profile. The polymer LED with different molar equivalents of Lewis acids was investigated. The EL peak wavelength was gradually

In-depth characterization of self-healing polymers based on π–π interactions

• Josefine Meurer,
• Julian Hniopek,
• Johannes Ahner,
• Michael Schmitt,
• Jürgen Popp,
• Stefan Zechel,
• Kalina Peneva and
• Martin D. Hager

Beilstein J. Org. Chem. 2021, 17, 2496–2504, doi:10.3762/bjoc.17.166

• 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

• Azra Kocaarslan,
• Zafer Eroglu,
• Önder Metin and
• Yusuf Yagci

Beilstein J. Org. Chem. 2021, 17, 2477–2487, doi:10.3762/bjoc.17.164

• azide derivatives under both white LED and NIR light irradiation. Due to its deeper penetration of NIR light, the possibility of synthesizing different macromolecular structures such as functional polymers, cross-linked networks and block copolymer has also been demonstrated. The structural and

• clearly confirmed the successful chain-end functionalization. In addition, block copolymer formation via NIR activated CuAAC process between the polymers having antagonist click components, namely, polystyrene azide (PS-Az) and PCL-Alk, was investigated. At the end of irradiation in the presence of

• exfoliated BPNs and CuIICl2/PMDETA, polystyrene-b-poly(ε-caprolactone) (PS-b-PCL) is selectively formed (Scheme 2). Figure 5a displays the GPC traces of precursors PS-Az, PCL-Alk, and the block copolymer PS-b-PCL. As it can be seen, the trace of Ps-b-PCL block copolymer was clearly shifted to higher

Post-functionalization of drug-loaded nanoparticles prepared by polymerization-induced self-assembly (PISA) with mitochondria targeting ligands

• Janina-Miriam Noy,
• Fan Chen and
• Martina Stenzel

Beilstein J. Org. Chem. 2021, 17, 2302–2314, doi:10.3762/bjoc.17.148

• be taken into account that the drug can interfere with the block copolymer aggregation. Alternatively, the use of reactive polymers for the polymerization creates a functional anchor to enable post-functionalization of the PISA nanoparticles with drugs such as doxorubicin [35][36]. In a different

• not reacted, is buried inside the shell or NMR is not sufficiently sensitive to detect the attachment of an end group in large nanoparticles. In any case, this approach was inconclusive. Hence, the copolymer PP3 (p(PEGMA63-co-PENAO7) was used as a model compound and reacted with TPP-COOH under the

• and TEM microscopy. Control experiment: attachment of TPP-COOH to PP3 copolymer For the control experiment, PP3 (19.30 mg, 0.85 mmol of RAFT end group, 1 equiv) was dissolved in 1.5 mL of Milli-Q water and TPP-COOH (1.88 mg, 4.25 mmol, 5 equiv to RAFT end group), EDC·HCl (0.82 mg, 4.25 mmol, 5 equiv

Chemical syntheses and salient features of azulene-containing homo- and copolymers

• Vijayendra S. Shetti

Beilstein J. Org. Chem. 2021, 17, 2164–2185, doi:10.3762/bjoc.17.139

• -containing homo- and copolymers, including brief descriptions of their key properties. Keywords: azulene; chemical synthesis; copolymer; non-alternant hydrocarbon; organic electronics; polyazulene; Introduction Azulene (C10H8) is a non-alternant, non-benzenoid, 10 π electron aromatic hydrocarbon containing

• , Aliquat 336, Pd(PPh3)4, toluene, 110 °C, 12%. Synthesis of azulene-benzodithiophene copolymer 54 and azulene-bithiophene copolymer 56. Synthesis of (A) 5,5’-bis(trimethylstannyl)-3,3’-didodecyl-2,2’-bithiophene (60) and (B) azulene-bithiophene copolymers 61–65 containing varied ratios of different

• ), (B) azulene-fluorene copolymer 126, and (C) azulene-fluorene copolymer 129. Synthesis of 2-arylazulene-fluorene copolymers 131–134. Synthesis of azulene-fluorene-benzothiadiazole terpolymers 136–138. Synthesis of azulene-carbazole-benzothiadiazole-conjugated polymers 140–144. Synthesis of (A) azulene

Constrained thermoresponsive polymers – new insights into fundamentals and applications

• Patricia Flemming,
• Alexander S. Münch,
• Andreas Fery and
• Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

• absolute length of the block copolymer and the relative length of the blocks to each other and the glass transition temperature. If a block is composed of a thermoresponsive polymer, the amphiphilic character and self-assembly ability can be altered by changing the temperature. The thermoresponsive block

• . Interestingly, the individual monomers usually do not exhibit responsive properties. However, the combination within a copolymer leads to a pronounced thermoresponse. A prominent representative of such behavior is poly(acrylamide-co-acrylonitrile), which is assembled from a fully soluble, hydrophilic monomer

• (AAm) and the hydrophobic AN block [51][52][94]. Since the phase transition temperature of the copolymer can be adjusted over a wide temperature range via the ratio of the two monomers, it is frequently used for the development of novel drug release systems [272][273][274][275][276]. Due to the

Recent advances in the application of isoindigo derivatives in materials chemistry

• Andrei V. Bogdanov and
• Vladimir F. Mironov

Beilstein J. Org. Chem. 2021, 17, 1533–1564, doi:10.3762/bjoc.17.111

• considerable interest of researchers in the field of organic electronics [92][93][94]. Isoindigo derivatives have similar characteristics. Taking into account these data, copolymers 51 containing up to 25% DPP units were obtained [95]. Despite the good prerequisites, an OFET based on this copolymer showed only

Valorisation of plastic waste via metal-catalysed depolymerisation

• Francesca Liguori,
• Carmen Moreno-Marrodán and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53

• accounts for around 8% by weight and 12% by volume of the world's solid waste [159][160]. PET is a copolymer of terephthalic acid (TPA) and EG [161]. It is best soluble in chlorophenol, tetrachloroethane, m-cresol, NMP, nitrobenzene and 1,1,1,3,3,3-hexafluoro-2-propanol, insoluble in common alcohols and

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

Photophysics and photochemistry of NIR absorbers derived from cyanines: key to new technologies based on chemistry 4.0

• Bernd Strehmel,
• Christian Schmitz,
• Ceren Kütahya,
• Yulian Pang,
• Anke Drewitz and
• Heinz Mustroph

Beilstein J. Org. Chem. 2020, 16, 415–444, doi:10.3762/bjoc.16.40

Formal preparation of regioregular and alternating thiophene–thiophene copolymers bearing different substituents

• Atsunori Mori,
• Keisuke Fujita,
• Chihiro Kubota,
• Toyoko Suzuki,
• Kentaro Okano,
• Takuya Matsumoto,
• Takashi Nishino and
• Masaki Horie

Beilstein J. Org. Chem. 2020, 16, 317–324, doi:10.3762/bjoc.16.31

• copolymer; nickel(II) catalyst; oligosiloxane; regioregular polythiophene; solubility; Introduction Polythiophenes attract much attention in materials science because of their extended π-conjugation, which is applied for a wide range of electronic materials. In particular, the regioregular polymers with a

• substituents. We envisaged that such an alternating copolymer in perfect regularity can be achieved by deprotonative polymerization employing a bithiophene with different substituents at the 3- and 3'-position. We have recently shown that the coupling of 2-chloro-3-substituted thiophene 2 with 2-bromo-3

• also examined preliminarily, and it was confirmed that the alternating copolymer was obtained with extremely high regularity. Herein, we wished to study the polymerization of bithiophene 4 possessing several kinds of substituents and a variety of functionalities. Since the homopolymer is considered

Design and synthesis of multivalent α-1,2-trimannose-linked bioerodible microparticles for applications in immune response studies of Leishmania major infection

• Chelsea L. Rintelmann,
• Tara Grinnage-Pulley,
• Kathleen Ross,
• Daniel E. K. Kabotso,
• Angela Toepp,
• Anne Cowell,
• Christine Petersen,
• Balaji Narasimhan and
• Nicola Pohl

Beilstein J. Org. Chem. 2019, 15, 623–632, doi:10.3762/bjoc.15.58

• intracellular monitoring and validation of T cell antigen presentation. This new probe would also be linked to the surface of a polyanhydride copolymer microparticle based on 1,6-bis(p-carboxyphenoxy)hexane (CPH) and sebacic anhydride (SA) to allow for enhanced internalization and uptake of the immunogenic

Application of olefin metathesis in the synthesis of functionalized polyhedral oligomeric silsesquioxanes (POSS) and POSS-containing polymeric materials

• Patrycja Żak and
• Cezary Pietraszuk

Beilstein J. Org. Chem. 2019, 15, 310–332, doi:10.3762/bjoc.15.28

• commercial availability. The choice of solvents is determined by the solubility of monomers, with methylene chloride, chloroform, and toluene being the most commonly used. Polymerization is terminated by addition of ethyl vinyl ether to the reaction mixture. Ruthenium residues from the obtained copolymer are

• heptacyclopentylnorbornenylethyloctasilsesquioxane and its copolymerization with cyclooctene [43]. The obtained copolymer was subsequently hydrogenated to afford polyethylene–POSS random copolymer (Scheme 21). Thermogravimetric analysis of the polyethylene–POSS copolymers under air showed a significant improvement of the thermal stability relative

• the range of 1.3–1.9. The surface morphology and thermal properties of hybrids were found to be affected by the POSS macromer. TEM analysis of copolymer films revealed the presence of POSS agglomerates. An analogous macromer bearing POSS-bound via phenylene linker was used in the synthesis of a series

Olefin metathesis in multiblock copolymer synthesis

• Maria L. Gringolts,
• Yulia I. Denisova,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2019, 15, 218–235, doi:10.3762/bjoc.15.21

• topic attracts special interest due to its relative simplicity and broad opportunities to tailor the structure and hence the properties of the copolymer products. Whenever possible, we analyze the structure–property relations for multiblock copolymers and point to their possible practical applications

• the research is devoted to diblock and triblock copolymers, whereas multiblock copolymer studies are still much less common [3][4][16][17][18]. Aside from more complicated synthesis and characterization of multiblock copolymers, for decades it was thought that any sequence disorder along polymer

• approaches to multiblock copolymer syntheses via olefin metathesis reactions developed mainly over the past ten years. The following sections address the achievements and perspectives of three main techniques used for this purpose, namely, sequential ring-opening metathesis polymerization, coupling of end

Ruthenium-based olefin metathesis catalysts with monodentate unsymmetrical NHC ligands

• Veronica Paradiso,
• Chiara Costabile and
• Fabia Grisi

Beilstein J. Org. Chem. 2018, 14, 3122–3149, doi:10.3762/bjoc.14.292

• ) with cyclooctene (COE, 47) and cyclopentene (CPE, 48), respectively (Scheme 6). An NBE/COE ratio of 1:50 was found necessary to realize a copolymer containing 97% of alternating diads ([poly(NBE-alt-COE)n]), while an NBE/CPE ratio of only 1:7 resulted in the formation of a copolymer with roughly 90% of

• -substituent provided the copolymer with the highest amount of alternating diads (98%) at an NBE/COE ratio of 1:10. However, the molecular mass of the copolymers was far lower than the theoretical value, suggesting that competitive chain-termination reactions occur. The pronounced steric bulk on the

• role in the formation of alternating diads. Indeed, the proportion of alternating copolymer increases moving from the small methyl group (54) to the large cyclohexyl group (56). Unsymmetrical catalysts based on NHC units possessing one alkyl substituent (propyl (59) or benzyl (60)) and one mesityl

Copolymerization of epoxides with cyclic anhydrides catalyzed by dinuclear cobalt complexes

• Yo Hiranoi and
• Koji Nakano

Beilstein J. Org. Chem. 2018, 14, 2779–2788, doi:10.3762/bjoc.14.255

• evaluated through the copolymerization of PO with PA (Table 1). For a convenient comparison of the different catalytic systems, the catalytic activity is expressed in terms of turnover frequency [TOF, (mol of PA incorporated in the copolymer)·(mol of Co center)−1·h−1]. First, the copolymerization was

• stereochemistry of the copolymer prepared from enantiomerically pure (S)-PO. Because a ring opening at the methine carbon results in both a regioerror and the inversion of stereochemistry at the stereocenter, the enantiomeric excess (ee) of the repeating unit in the copolymer should reflect the regioregularity

• [15]. The ee of propylene glycol, which was obtained after hydrolysis of the copolymer obtained with (S)-PO and PA, was found to be 88%, indicating a high level of regioregularity. Molecular weight distributions are relatively narrow, while a bimodal distribution was observed in the SEC traces. The

An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes

• Hashem Sharghi,
• Pezhman Shiri and
• Mahdi Aberi

Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253

• copolymer synthesized by Friedel–Crafts alkylation of triphenylamine (115) with dibromo-p-xylene 112 was prepared (Scheme 21). After the sulfonation process, the resulted material has been employed as a heterogeneous, reusable, and environmentally benign catalyst in the multicomponent synthesis of

Comparative cell biological study of in vitro antitumor and antimetastatic activity on melanoma cells of GnRH-III-containing conjugates modified with short-chain fatty acids

• Eszter Lajkó,
• Sarah Spring,
• Rózsa Hegedüs,
• Beáta Biri-Kovács,
• Sven Ingebrandt,
• Gábor Mező and
• László Kőhidai

Beilstein J. Org. Chem. 2018, 14, 2495–2509, doi:10.3762/bjoc.14.226

• effect on melanoma cell proliferation via blocking cell cycle progression in G2/M phase. In a previous study, Pályi and his co-workers demonstrated that a conjugate containing GnRH analog + copolymer could also cause the accumulation of endometrial cancer cells in the G2/M phase [45]. In contrast to

Fluorogenic PNA probes

• Tirayut Vilaivan

Beilstein J. Org. Chem. 2018, 14, 253–281, doi:10.3762/bjoc.14.17

• ]. On the other hand, a polycationic comb-type dextran-poly(lysine) copolymer was shown to strongly promote the strand exchange of PNA–DNA duplexes by another DNA strand [110]. The equilibrium of the strand displacement reaction lies on the side of the more stable duplex, and so the original strand