Synthesis and supramolecular properties of regioisomers of mononaphthylallyl derivatives of γ-cyclodextrin

• Markéta Bláhová,
• Sergey K. Filippov,
• Lubomír Kováčik,
• Jiří Horský,
• Simona Hybelbauerová,
• Zdenka Syrová,
• Tomáš Křížek and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2017, 13, 2509–2520, doi:10.3762/bjoc.13.248

• were studied by a set of methods allowing characterization of supramolecular behavior at various levels – from binary complexation, over supramolecular oligomers to large assemblies; namely by isothermal titration calorimetry (ITC) [16], 1H nuclear magnetic resonance spectroscopy (1H NMR), dynamic

• consequently, longer oligomers can be expected for it. The fraction of suprapolymer with polymerization degree n is then given for negligible cyclisation as where θ is the degree of occupation, i.e., the probability that the particular group, either naphthyl or CD, is in a bound state. θ is determined by the

• , the good fit, observed at least for the 2-O- and 3-O-regioisomers, identifies the 1:1 complexation as the probably dominant associative process. The presence of unimers and/or short oligomers was confirmed by DLS even though objects with corresponding hydrodynamic diameters of a few nm were observed

Phosphonic acid: preparation and applications

• Charlotte M. Sevrain,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2017, 13, 2186–2213, doi:10.3762/bjoc.13.219

• primary adduct R3B···O=PR(OR')2 which was subsequently decomposed as borophosphonates oligomers through a bis-bromodealkylation [203]. The phosphonic acids were finally obtained after methanolysis with quantitative conversion and yields up to 95%. Interestingly, this procedure is selective to P–O

Superstructures with cyclodextrins: Chemistry and applications IV

• Gerhard Wenz

Beilstein J. Org. Chem. 2017, 13, 2157–2159, doi:10.3762/bjoc.13.215

• repulsive. The first examples of superstructures formed by attractive intermolecular forces were complexes of crown ethers [1], cryptands [2] and spherands [3], which were recognized by the 1987 Nobel Prize in Chemistry. In addition, inclusion compounds of cyclodextrins (CDs), cyclic oligomers of glucose

Preactivation-based chemoselective glycosylations: A powerful strategy for oligosaccharide assembly

• Weizhun Yang,
• Bo Yang,
• Sherif Ramadan and
• Xuefei Huang

Beilstein J. Org. Chem. 2017, 13, 2094–2114, doi:10.3762/bjoc.13.207

• acceptor 41 to the reaction mixture furnished trisaccharide 42. This approach was applied to the synthesis of hyaluronic acid (HA) oligomers [39]. The sequential reaction of building blocks 43, 44 and 46 led to HA trisaccharide 47 (Scheme 10). The modest overall yield of 26% for the two glycosylation

Intramolecular glycosylation

• Xiao G. Jia and
• Alexei V. Demchenko

Beilstein J. Org. Chem. 2017, 13, 2028–2048, doi:10.3762/bjoc.13.201

• Xiao G. Jia Alexei V. Demchenko Department of Chemistry and Biochemistry, University of Missouri – St. Louis, One University Blvd., 434 Benton Hall (MC27), St. Louis, MO 63121, USA 10.3762/bjoc.13.201 Abstract Carbohydrate oligomers remain challenging targets for chemists due to the requirement

β-Cyclodextrin- and adamantyl-substituted poly(acrylate) self-assembling aqueous networks designed for controlled complexation and release of small molecules

• Liang Yan,
• Duc-Truc Pham,
• Philip Clements,
• Stephen F. Lincoln,
• Jie Wang,
• Xuhong Guo and
• Christopher J. Easton

Beilstein J. Org. Chem. 2017, 13, 1879–1892, doi:10.3762/bjoc.13.183

• self-assembling aqueous polymer networks through the complexation of hydrophobic polymer substituents by cyclodextrin oligomers [1][2][3][4] and cyclodextrin substituted polymers [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] to form cross-links between polymer strands is well-established

• and the PAAADen, PAAADhn or PAAADddn strands. The adamantyl group is selected as the guest substituent as it is strongly complexed by β-CD [48], β-CD oligomers [3][4] and β-CD-substituted polymers [10][14][16], and drives the self-assembly of aqueous chitosan [1][5][9], hyaluronic acid [8][9] and poly

New electroactive asymmetrical chalcones and therefrom derived 2-amino- / 2-(1H-pyrrol-1-yl)pyrimidines, containing an N-[ω-(4-methoxyphenoxy)alkyl]carbazole fragment: synthesis, optical and electrochemical properties

• Daria G. Selivanova,
• Alexei A. Gorbunov,
• Olga A. Mayorova,
• Alexander N. Vasyanin,
• Igor V. Lunegov,
• Elena V. Shklyaeva and
• Georgii G. Abashev

Beilstein J. Org. Chem. 2017, 13, 1583–1595, doi:10.3762/bjoc.13.158

• obtained in this area of scientific and technical research confirms that at present time it is really possible to perform tailor-made syntheses of monomers to gain oligomers and polymers with desired properties and characteristics. The conjugated systems including carbazole units possess important

Molecular recognition of N-acetyltryptophan enantiomers by β-cyclodextrin

• Spyros D. Chatziefthimiou,
• Mario Inclán,
• Petros Giastas,
• Athanasios Papakyriakou,
• Konstantina Yannakopoulou and
• Irene M. Mavridis

Beilstein J. Org. Chem. 2017, 13, 1572–1582, doi:10.3762/bjoc.13.157

• the enhancement of solubility, bioavailability and stability of drugs [2][3][4][5]. Moreover, being oligomers of α-D-glucopyranose, CDs possess an intrinsic chirality, thus they form diastereomeric inclusion complexes with enantiomeric pairs and frequently they exhibit enantioselectivity in aqueous

Chemical systems, chemical contiguity and the emergence of life

• Terrence P. Kee and
• Pierre-Alain Monnard

Beilstein J. Org. Chem. 2017, 13, 1551–1563, doi:10.3762/bjoc.13.155

• eutectic phase in water/ice [35][36][37], but computer modelling [38] and preliminary wet-chemistry experiments, which show a selective accumulation of long oligomers [39], already hint at the possibility of similar processes taking place in mineral formations. In the same environments, short peptides

• nucleic acid oligomers [53][54][55]. The presence of the mineral support is crucial here as it permits the preservation of the amphiphile bilayer structure during drying, thereby promoting the conversion of an “unreactive” organization (free floating vesicles and free monomers) into reactive chemical

Synthesis of oligonucleotides on a soluble support

• Harri Lönnberg

Beilstein J. Org. Chem. 2017, 13, 1368–1387, doi:10.3762/bjoc.13.134

• . Several of protocols developed for the soluble-supported synthesis allow the preparation of both DNA and RNA oligomers of limited length in gram scale without any special equipment, being evidently of interest for research groups that need oligonucleotides in large amounts for research purposes. However

• atomic economy, i.e., small amount of support material compared to the amount of ORN obtained and the moderate consumption of solvent (MeOH) required for really quantitative precipitation of the support-bound oligonucleotides. However, only short oligomers have been so far prepared on this support

• . Support loaded with longer fully protected oligomers may precipitate less quantitatively or interchain aggregation may reduce the coupling efficiency. A closely related support 6, incorporating additionally a Q-linker moiety [44], has been used for preparation of fully protected ODN trimers having only

Interactions between shape-persistent macromolecules as probed by AFM

• Johanna Blass,
• Jessica Brunke,
• Franziska Emmerich,
• Cédric Przybylski,
• Vasil M. Garamus,
• Artem Feoktystov,
• Roland Bennewitz,
• Gerhard Wenz and
• Marcel Albrecht

Beilstein J. Org. Chem. 2017, 13, 938–951, doi:10.3762/bjoc.13.95

• polymers have been reported so far, including CD-modified conjugated oligomers and polymers composed of rigid phenylene ethynylene (PPE) structure units which are able to form self-inclusion complexes with tunable electrochemical properties [29][30][31][32][33][34][35]. The synthesis of PPE, in which two β

Expression, purification and structural analysis of functional GABA transporter 1 using the baculovirus expression system

• Jing Hu,
• Chris Weise,
• Christoph Böttcher,
• Hua Fan and
• Jian Yin

Beilstein J. Org. Chem. 2017, 13, 874–882, doi:10.3762/bjoc.13.88

• forming oligomers during purification, different detergents were tested, and n-dodecyl-β-D-maltoside (DDM, 0.05%) was found to efficiently maintain the protein in its monomeric form (Figure 5A). The SE-FPLC elution profile is shown in Figure 5A. Peak 1, which appears at 13.5–14 mL, corresponds to a

Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications

• Vinila N. Viswanathan,
• Arun D. Rao,
• Upendra K. Pandey,
• Arul Varman Kesavan and
• Praveen C. Ramamurthy

Beilstein J. Org. Chem. 2017, 13, 863–873, doi:10.3762/bjoc.13.87

• methanol and subsequently treated with N,N-diethyl phenylazothioformamide in chloroform to remove any palladium impurities. Furthermore, unreacted reagents and oligomers were removed by successive Soxhlet extraction with methanol, hexane, and chloroform, respectively. The chloroform-soluble fraction of the

Cyclodextrins tethered with oligolactides – green synthesis and structural assessment

• Cristian Peptu,
• Mihaela Balan-Porcarasu,
• Alena Šišková,
• Ľudovít Škultéty and
• Jaroslav Mosnáček

Beilstein J. Org. Chem. 2017, 13, 779–792, doi:10.3762/bjoc.13.77

• commonly encountered in synthetic polymers. Moreover, the presence of multiple initiating sites may favor the formation of star-like oligomers. A particular issue, still under debate, is related to the possibility that in spite of multiple reactive points, namely the OH groups, which can be involved in

• first group appear at low elution time (from 2 to 4 min) and has increased water solubility, suggesting the presence of unmodified CD and CDs with low substitution degree. The second group, eluted from 9 to 18 minutes, contained modified CDs and PLA oligomers. The overlaid LC chromatograms for crude α

• oligomers with odd number of monomer units could be observed as well. These oligomer species with odd number of lactates resulted from intramolecular and/or intermolecular transesterification reactions and are in lower amount, when compared with the oligomers containing even number of monomers. This

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

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

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

• ” 1% Pd@Al2O3 (Table 1, entry 5) showed to be poorly selective (67%), resulting in considerable amounts of oligomers and over-hydrogenated product 1b [121]. The performance of the above systems was compared with that of a single-site catalyst based on Pd atoms confined into the “six-fold cavities” of

Continuous N-alkylation reactions of amino alcohols using γ-Al₂O₃ and supercritical CO₂: unexpected formation of cyclic ureas and urethanes by reaction with CO₂

• Emilia S. Streng,
• Darren S. Lee,
• Michael W. George and
• Martyn Poliakoff

Beilstein J. Org. Chem. 2017, 13, 329–337, doi:10.3762/bjoc.13.36

• ). For this reaction, self-optimisation is important as multiple products were identified that could form in parallel; from 1 the possible products we expected to see were a mixture of piperidine (2a), N-methylpiperidine (2b), N- and O-methylated 1, as well as oligomers. We chose to target 2b only for

Synthesis of acylhydrazino-peptomers, a new class of peptidomimetics, by consecutive Ugi and hydrazino-Ugi reactions

• Angélica de Fátima S. Barreto,
• Veronica Alves dos Santos and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2016, 12, 2865–2872, doi:10.3762/bjoc.12.285

• some of the most important classes of peptidomimetics so far obtained and highlights the differences among them. Of these, peptoids (oligomers of N-substituted glycine residues) [9][10][11][12] are the most common and may have interesting biological activities. For instance, peptoid 1 is a target for

Interactions between cyclodextrins and cellular components: Towards greener medical applications?

• Loïc Leclercq

Beilstein J. Org. Chem. 2016, 12, 2644–2662, doi:10.3762/bjoc.12.261

• , Lovatt and co-workers investigated the dissociation of bovine insulin oligomers induced by aqueous solution of α-, HP-β-, and ME-β-CD [89]. The energetics of the dissociation of insulin oligomers have been investigated by microcalorimetry. As expected, the dissociation of insulin oligomers is increased

• upon the addition of CDs. This dissociation is clearly related to the interaction of these CDs with the protein side chains. Indeed, the dissociation of insulin oligomers is endothermic without CDs whereas in the presence of α-CD, the dissociation is less endothermic due to the exothermic binding of α

Inhibition of peptide aggregation by means of enzymatic phosphorylation

• Kristin Folmert,
• Malgorzata Broncel,
• Hans v. Berlepsch,
• Christopher H. Ullrich,
• Mary-Ann Siegert and
• Beate Koksch

Beilstein J. Org. Chem. 2016, 12, 2462–2470, doi:10.3762/bjoc.12.240

• recognition motif for PKA (cAMP-dependent protein kinase) that enables enzymatic phosphorylation. We have analyzed the pathway of amyloid formation and the influence of enzymatic phosphorylation on the different states along the conformational transition from random-coil to β-sheet-rich oligomers to

• protofilaments and on to insoluble amyloid fibrils, and we found a remarkable directing effect from β-sheet-rich structures to unfolded structures in the initial growth phase, in which small oligomers and protofilaments prevail if the peptide is phosphorylated. Keywords: aggregation; amyloids; peptide models

• structures and a constantly low intensity for β-sheets over seven days of incubation (Figure 4a). Together with the TEM micrograph, which shows no sign of amyloid morphologies or other higher oligomers, the results suggest the inhibition of amyloid formation of KMF6 by enzymatic phosphorylation. Also, no

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

• oligomers during Soxhlet extraction as well as the known overestimation of molecular weight for polythiophenes when measured by GPC against polystyrene standards [50][51]. Accounting for the purification, the Mn of P3OT-b-F-P3OT 2:1 is in reasonable agreement with the ratio of H and F blocks as determined

DNA functionalization by dynamic chemistry

• Zeynep Kanlidere,
• Oleg Jochim,
• Marta Cal and
• Ulf Diederichsen

Beilstein J. Org. Chem. 2016, 12, 2136–2144, doi:10.3762/bjoc.12.203

• presynthesized oligomers with abasic sites on the backbone for the addition of individual monomeric nucleobases and consider the synthesis of new oligonucleotide analogues possessing different backbone topologies [41]. Ghadiri et al. employed this approach for an enzyme-free synthesis of an oligonucleotide

Superelectrophilic activation of 5-hydroxymethylfurfural and 2,5-diformylfuran: organic synthesis based on biomass-derived products

• Dmitry S. Ryabukhin,
• Dmitry N. Zakusilo,
• Mikhail O. Kompanets,
• Anton A.Tarakanov,
• Irina A. Boyarskaya,
• Tatiana O. Artamonova,
• Mikhail A. Khohodorkovskiy,
• Iosyp O. Opeida and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2016, 12, 2125–2135, doi:10.3762/bjoc.12.202

• superacid TfOH o- and m-xylenes gave rise to complex oligomeric mixtures (Table 5, entries 10 and 12) having masses up to 1400–1500 Da according to MALDI–MS (see Supporting Information File 1). These oligomers may have formed due to the participation of both aldehyde groups of species D (see Scheme 1 and

Thiophene-forming one-pot synthesis of three thienyl-bridged oligophenothiazines and their electronic properties

• Dominik Urselmann,
• Konstantin Deilhof,
• Bernhard Mayer and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2016, 12, 2055–2064, doi:10.3762/bjoc.12.194

• intramolecular electronic coupling of (oligo)phenothiazines [45][64] and the low torsional displacement from a coplanar arrangement of both redox moieties of the dumbbells might represent conjugatively linked nanometer-scaled novel multistep redox active oligomers. As part of our concept to develop novel

• mass spectrometry (MALDI–TOF). The proton and carbon NMR spectra unambiguously support the formation of the oligomers 3, and expectedly, in agreement with the molecular symmetry, the appearance of one (3a), two (3b), and three (3c) distinct resonances for the nitrogen-bound methylene carbon nuclei in

Star-shaped and linear π-conjugated oligomers consisting of a tetrathienoanthracene core and multiple diketopyrrolopyrrole arms for organic solar cells

• Hideaki Komiyama,
• Chihaya Adachi and
• Takuma Yasuda

Beilstein J. Org. Chem. 2016, 12, 1459–1466, doi:10.3762/bjoc.12.142

• (OPERA), Kyushu University 10.3762/bjoc.12.142 Abstract Solution-processable star-shaped and linear π-conjugated oligomers consisting of an electron-donating tetrathienoanthracene (TTA) core and electron-accepting diketopyrrolopyrrole (DPP) arms, namely, TTA-DPP4 and TTA-DPP2, were designed and

• (40–60 nm). Keywords: bulk heterojunction; diketopyrrolopyrrole; organic solar cells; star-shaped oligomers; tetrathienoanthracene; Introduction Solution-processable organic semiconductors have been intensively studied as key materials for low-cost, flexible, and large-area optoelectronic devices

• -accepting diketopyrrolopyrrole (DPP) arms, and its linear analogue, TTA-DPP4 and TTA-DPP2 (Figure 1). TTA can be regarded as a promising central core unit for star-shaped π-conjugated oligomers, and has previously been utilized as a building block of semiconducting polymers for OSCs [24] and organic field

From N-vinylpyrrolidone anions to modified paraffin-like oligomers via double alkylation with 1,8-dibromooctane: access to covalent networks and oligomeric amines for dye attachment

• Daniela Obels,
• Melanie Lievenbrück and
• Helmut Ritter

Beilstein J. Org. Chem. 2016, 12, 1395–1400, doi:10.3762/bjoc.12.133

• paraffin-like oligomeric chains bearing polymerizable vinyl moieties. These oligomers were radically crosslinked in bulk with N-VP as co-monomer yielding swellable polymer disks. The vinylic side groups of the N-VP oligomers allow thiol–ene click reactions with 2-aminoethanethiol hydrochloride to obtain

• reactive amino-functionalized oligomers. Further modification of the free amino groups with 1,4-difluoro-9,10-anthraquinone (DFA) yields red-colored oligomeric anthraquinone dyes. The final reaction of DFA-substituted N-VP oligomers with Jeffamine® M 600 leads to blue-colored and branched oligomers with

• intramolecular reaction. Until now, dibromo compounds were mainly used to synthesize symmetric cross linker [22][26][27]. To the best of our knowledge, the synthesis of modified paraffin-like oligomers via double alkylation of N-VP with aliphatic dibromides was not yet described in literature. In general, the