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

• ). 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

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

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

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

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

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

• ” ROMP [51]. Copolymerization of norbornenylethyloctasilsesquioxane with 2-endo-3-exo-5-norbornene-2,3-dicaboxylic acid trimethylsilyl ester was performed in the presence of Ru-1. The block copolymer was obtained via sequential monomer addition (Scheme 27). After hydrolysis of the ester function, the

• containing pendant poly(ethylene oxide) group permitted the synthesis of a number of block copolymers, containing blocks of hydrophobic nature (POSS containing block) and those of hydrophilic nature (polyether containing block, Scheme 29). The block copolymer was synthesized via sequential monomer addition

• -oxanorbornene-5,6-dicarboximide DCPD. Ring-opening metathesis copolymerization of POSS-NBE with methyltetracyclododecene. Synthesis of block copolymer via ROMP by sequential monomer addition. Synthesis of a liquid crystalline polymer with POSS core in the side chain. Sequential synthesis of copolymers of

Binding abilities of polyaminocyclodextrins: polarimetric investigations and biological assays

• Marco Russo,
• Daniele La Corte,
• Annalisa Pisciotta,
• Serena Riela,
• Rosa Alduina and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2017, 13, 2751–2763, doi:10.3762/bjoc.13.271

• their interaction with sodium alginate (Alg). This is an easily available and stable block copolymer, constituted by β-D-mannuronate and β-L-guluronate units linked by 1→4 glycosidic bridges. Therefore, it seemed an ideal candidate as model polyanion, in order to study the stoichiometric and

Block copolymers from ionic liquids for the preparation of thin carbonaceous shells

• Sadaf Hanif,
• Bernd Oschmann,
• Dmitri Spetter,
• Muhammad Nawaz Tahir,
• Wolfgang Tremel and
• Rudolf Zentel

Beilstein J. Org. Chem. 2017, 13, 1693–1701, doi:10.3762/bjoc.13.163

• monomer by RAFT polymerization. This allows the control over the molecular weight of ionic liquid blocks in the range of 8000 and 22000 and of the block-copolymer synthesis. In this work we focus on block copolymers with an anchor block. They can be used to control the formation of TiO2 nanoparticles

• , which are functionalized thereafter with a block of ionic-liquid polymer. Pyrolysis of these polymer functionalized inorganic nanoparticles leads to TiO2 nanoparticles coated with a thin carbonaceous shell. Such materials may, e.g., be interesting as battery materials. Keywords: block copolymer; carbon

• anchor group could bind to inorganic nanoparticle surfaces, where a second polymer block could be converted into a conductive carbon shell, improving the properties of nanoparticles like TiO2 or ZnO with respect to the reversible storage of lithium or sodium ions [22][23][24][25]. Using a block copolymer

2-Methyl-2,4-pentanediol (MPD) boosts as detergent-substitute the performance of ß-barrel hybrid catalyst for phenylacetylene polymerization

• Julia Kinzel,
• Daniel F. Sauer,
• Marco Bocola,
• Marcus Arlt,
• Tayebeh Mirzaei Garakani,
• Andreas Thiel,
• Klaus Beckerle,
• Tino Polen,
• Jun Okuda and
• Ulrich Schwaneberg

Beilstein J. Org. Chem. 2017, 13, 1498–1506, doi:10.3762/bjoc.13.148

• been reported by protecting its hydrophobic transmembrane region in the presence of a detergent such as octylpolyoxyethylene (oPOE) or block copolymer such as PE–PEG [19][28][31][41][42][43][44]. Although PE–PEG improves protein solubility, polymerization reactions utilizing FhuA ΔCVFtev as protein

• block copolymer PE–PEG and amphiphilic MPD are used, respectively. Refolding is achieved by dialysis of the protein in a solution containing the particular refolding agents. The structural integrity of FhuA ΔCVFtev was confirmed with CD spectroscopy (Figure 3). When either PE–PEG or MPD is applied, the

One-pot synthesis of block-copolyrotaxanes through controlled rotaxa-polymerization

• Jessica Hilschmann,
• Gerhard Wenz and
• Gergely Kali

Beilstein J. Org. Chem. 2017, 13, 1310–1315, doi:10.3762/bjoc.13.127

• further effects the CD content and the aqueous solubility of the polyrotaxane. Keywords: block copolymer; cyclodextrin; polyisoprene; polyrotaxane; RAFT polymerization; Introduction Polymer necklaces, i.e., polyrotaxanes and pseudopolyrotaxanes, are supramolecular assemblies comprising polymeric axes

• ]. There are several CD-based polyrotaxanes known with homo- and block-copolymer axes, mostly based on poly(ethylene oxide), poly(propylene oxide) or their copolymers [15][16][17][18][19][20][21], since these polymers can form sufficiently stable complexes with CDs. The application potential of these

• –2.3 and 5.0 ppm and of polyHEMA at 0.7–2.1 and 3.3–4.0 ppm. The noticeable peak broadening again is indicative of the formation of ABA triblock-copolyrotaxane. The DOSY measurements were carried out for the block-copolymer polyrotaxanes in DMSO. The same diffusion coefficients were detected for all

Comparing blends and blocks: Synthesis of partially fluorinated diblock polythiophene copolymers to investigate the thermal stability of optical and morphological properties

• Pierre Boufflet,
• Sebastian Wood,
• Jessica Wade,
• Zhuping Fei,
• Ji-Seon Kim and
• Martin Heeney

Beilstein J. Org. Chem. 2016, 12, 2150–2163, doi:10.3762/bjoc.12.205

• (KCTP) conditions. We compare the behavior of the block copolymer to that of the corresponding homopolymer blends. In both types of system, we find the fluorinated segments tend to dominate the UV–visible absorption and molecular vibrational spectral features, as well as the thermal behavior. In the

• block copolymer case, non-fluorinated segments appear to slightly frustrate the aggregation of the more fluorinated block. However, in situ temperature dependent Raman spectroscopy shows that the intramolecular order is more thermally stable in the block copolymer than in the corresponding blend

• , suggesting that such materials may be interesting for enhanced thermal stability of organic photovoltaic active layers based on similar systems. Keywords: conjugated block-copolymer synthesis; fluorination; microphase stabilization; polythiophene; temperature-dependent Raman spectroscopy; Introduction With

Supramolecular polymer assembly in aqueous solution arising from cyclodextrin host–guest complexation

• Jie Wang,
• Zhiqiang Qiu,
• Yiming Wang,
• Li Li,
• Xuhong Guo,
• Duc-Truc Pham,
• Stephen F. Lincoln and
• Robert K. Prud’homme

Beilstein J. Org. Chem. 2016, 12, 50–72, doi:10.3762/bjoc.12.7

• , these clusters grow into stable crystal-like structures such that the hydrogel functions similarly to a block copolymer with hard segments composed of micro-crystalline methylated α-CD and softer segments composed of polyethylene glycol in the hydrogel. The preparations of the copolymers of either N,N

• adamantyl dimer f [81]. The formation of a AD-PEG micelle followed by the formation of a AD-PEG/α-CD supramolecular hydrogel in aqueous solution [88]. Interaction of PEG-b-PAA block copolymer with cis-diamminedichloroplatinum(II), cisplatin, to form a PEG-b-PAA-cisplatin micelle followed by the addition of

Recent advances in metathesis-derived polymers containing transition metals in the side chain

• Ileana Dragutan,
• Valerian Dragutan,
• Bogdan C. Simionescu,
• Albert Demonceau and
• Helmut Fischer

Beilstein J. Org. Chem. 2015, 11, 2747–2762, doi:10.3762/bjoc.11.296

• copolymer 39 (Scheme 16). Remarkably, in water, this Rh-containing block copolymer readily generated micelles and could be thus successfully employed as a Rh-immobilized catalyst for the hydroformylation of 1-octene. Very recently, Matyjaszewski, Tang and coworkers [62] reported the first synthesis of

• norborn-5-ene-(N,N-dipyrid-2-yl)carbamide with exo,exo-[2-(3-ethoxycarbonyl-7-oxabicyclo[2.2.1]hept-5-en-2-carbonyloxy)ethyl]trimethylammonium iodide to polymer 38, using the Schrock Mo catalyst. By further reaction with [Rh(COD)Cl]2 (COD = cycloocta-1,5-diene), polymer 38 gave the Rh(I)-appended block

Self-assemblies of γ-CDs with pentablock copolymers PMA-PPO-PEO-PPO-PMA and endcapping via atom transfer radical polymerization of 2-methacryloyloxyethyl phosphorylcholine

• Jing Lin,
• Tao Kong,
• Lin Ye,
• Ai-ying Zhang and
• Zeng-guo Feng

Beilstein J. Org. Chem. 2015, 11, 2267–2277, doi:10.3762/bjoc.11.247

• appeared at 41.8 °C, due to the interference of the PMA blocks attaching to the two ends of PPO-PEO-PPO. However, compared with the macroinitiator, the penta-block copolymer and pure γ-CD, the PEP100M15CD and other PPR samples exhibited no endothermic peak in the range from 20 to 100 °C. This clearly

Regulation of integrin and growth factor signaling in biomaterials for osteodifferentiation

• Qiang Wei,
• Theresa L. M. Pohl,
• Anja Seckinger,
• Joachim P. Spatz and
• Elisabetta A. Cavalcanti-Adam

Beilstein J. Org. Chem. 2015, 11, 773–783, doi:10.3762/bjoc.11.87

• similar size compared to individual cell receptors, thus it is possible to target receptor-driven pathways and modulate cell responses [7]. Here, the cyclic RGDfK peptides are precisely immobilized on substrates via hexagonally close-packed gold nanodot arrays prepared by block-copolymer micelle

Release of β-galactosidase from poloxamine/α-cyclodextrin hydrogels

• César A. Estévez,
• José Ramón Isasi,
• Eneko Larrañeta and
• Itziar Vélaz

Beilstein J. Org. Chem. 2014, 10, 3127–3135, doi:10.3762/bjoc.10.330

• relative to the initial amount loaded for α-CD, Tetronic 90R4, and pulverized T25a10 tablets were 98.7 ± 6.0, 94.5 ± 6.8 and 97.4 ± 8.8, respectively. Note that even in the case of a mixture of the lactase protein with an amphiphilic block copolymer (such as Tetronic 90R4), the activity is as high as 95

• %. In this case, the block copolymer does not induce protein denaturation. Moreover, it has been found that poloxamers can have a positive effect on folding, since they suppress aggregation of denatured proteins [22]. With respect to storage time, the activity for pure lactase was compared to that of

Linear-g-hyperbranched and cyclodextrin-based amphiphilic block copolymer as a multifunctional nanocarrier

• Yamei Zhao,
• Wei Tian,
• Guang Yang and
• Xiaodong Fan

Beilstein J. Org. Chem. 2014, 10, 2696–2703, doi:10.3762/bjoc.10.284

• exhibit controlled drug release based on the diffusion release mechanism. The novel multifunctional nanocarrier may be applicable to produce highly efficient and specialized delivery systems for drugs, genes, and diagnostic agents. Keywords: amphiphilic block copolymer; cyclodextrin polymer

Loose-fit polypseudorotaxanes constructed from γ-CDs and PHEMA-PPG-PEG-PPG-PHEMA

• Tao Kong,
• Lin Ye,
• Ai-ying Zhang and
• Zeng-guo Feng

Beilstein J. Org. Chem. 2014, 10, 2461–2469, doi:10.3762/bjoc.10.257

• analyses indicated that γ-CDs can accommodate and slip over PHEMA blocks to randomly distribute along the entire pentablock copolymer chain. This results in unique, single-chain stranded PPRs showing no characteristic channel-type crystal structure. Keywords: block copolymer; γ-CD; loose-fit; poly(2

Copolymerization and terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salen)Co(III) complex tethering four quaternary ammonium salts

• Jong Yeob Jeon,
• Seong Chan Eo,
• Jobi Kodiyan Varghese and
• Bun Yeoul Lee

Beilstein J. Org. Chem. 2014, 10, 1787–1795, doi:10.3762/bjoc.10.187

• /diglycolic anhydride using a diiminate zinc catalyst has been reported. Here, the block copolymer of poly(ester-block-carbonate) was formed through the faster reaction of CHO/anhydride coupling, and after complete conversion of the anhydride, the carbonate block was grown by CO2/CHO coupling [29]. Porphyrin

• , only the carbonate units were grown, resulting in the formation of a block copolymer. One side of the block copolymer was gradient poly(1,2-propylene phthalate-co-carbonate), while the other side was poly(1,2-propylene carbonate). When 2.0 g of PA was fed along with 15 mg of ethanol, full conversion of

Restructuring polymers via nanoconfinement and subsequent release

• Alan E. Tonelli

Beilstein J. Org. Chem. 2012, 8, 1318–1332, doi:10.3762/bjoc.8.151

• IC (Figure 1). As a result, the segregation or mixing of PCL and PPO blocks in their CD-ICs is carried over to the coalesced tri-block copolymer samples, explaining the divergent crystallinities of the PCL blocks. The fact that the PCL-PPG-PCL triblock coalesced from its γ-CD IC is not dramatically

• obtained by first forming its IC with α-CD, followed by coalescence of the guest diblock copolymer chains, a readily biodegradable sample of the block copolymer with very low crystallinity was produced [16]. Compression molding between Teflon plates produced film samples of asr- and c-PCL-b-PLLA, PCL and

Miniemulsion polymerization as a versatile tool for the synthesis of functionalized polymers

• Daniel Crespy and
• Katharina Landfester

Beilstein J. Org. Chem. 2010, 6, 1132–1148, doi:10.3762/bjoc.6.130

• second step it was possible to cleave the azo-bonds and polymerize styrene in the nanodroplets. This approach hence combines free-radical polymerization and polyaddition for the production of hybrid block-copolymer particles. Polyurethanes can also be prepared in inverse miniemulsion if the monomers or

Novel multi-responsive P2VP-block-PNIPAAm block copolymers via nitroxide-mediated radical polymerization

• Cathrin Corten,
• Katja Kretschmer and
• Dirk Kuckling

Beilstein J. Org. Chem. 2010, 6, 756–765, doi:10.3762/bjoc.6.89

• radical polymerization (CRP), based on the idea of reversible chain termination, decreases the disadvantage of the free radical polymerization and permits the synthesis of defined block copolymer structures [13]. The growing demand for well-defined and functional soft materials in nanoscale applications

• smaller elution volume relative to the macroinitiator indicated successful block copolymer formation. No shoulder or second peak at elution volumes for macroinitiator was found, indicating that most of the polymers possessed intact structure. Additionally, the SEC traces show an overlap between the two

• varies with the fraction of protonation of P2VP. Hence, by titration it is not possible to measure the real pKa. In order to investigate the size of the micelles, dynamic light scattering experiments were performed on diluted block copolymer solutions under various conditions. The resulting hydrodynamic

Poly(glycolide) multi-arm star polymers: Improved solubility via limited arm length

• Florian K. Wolf,
• Anna M. Fischer and
• Holger Frey

Beilstein J. Org. Chem. 2010, 6, No. 67, doi:10.3762/bjoc.6.67

• compared to the homopolymer PGA should lead to simplified processing conditions. The findings contribute to broadening the range of biomedical applications of PGA. Keywords: block copolymer; hyperbranched; PGA; polyester; polyglycerol; poly(glycolide); star polymer; Introduction Linear aliphatic

• PG is believed to play an important role in the properties of the resulting star block copolymer, the branched topology and the distribution of OH groups therein are key factors that will also be addressed in the following text. Careful drying of the PG cores under vacuum is a crucial step for the

Synthesis and crossover reaction of TEMPO containing block copolymer via ROMP

• Olubummo Adekunle,
• Susanne Tanner and
• Wolfgang H. Binder

Beilstein J. Org. Chem. 2010, 6, No. 59, doi:10.3762/bjoc.6.59

• polymerization in comparison to U1. The synthesis of block copolymers with molecular weights up to Mn = 31 000 g/mol with low polydispersities (Mw/Mn = 1.2) is reported. Keywords: block copolymer (BCP); crossover reaction; MALDI; NEOLYST™; ROMP; Introduction Block copolymers are macromolecules composed of

• and 9, initiated via the catalysts U1–U3, as well as mass spectrometric investigations of the crossover reactions via MALDI methods. The incorporation of the free radical 9 into block copolymer is an important contribution in the generation of polymers for reversible charge storage materials, as

• synthesis of the BCP was achieved by use of this initiating system to yield the respective BCP-A10T10, A20T20, A25T25 and A50T50 with the expected molecular weight and with low polydispersity (see Table 1, entries 18–21). The GPC traces of A25 block and the A25T25 block copolymer are shown in Figure 7