One-pot syntheses of blue-luminescent 4-aryl-1H-benzo[f]isoindole-1,3(2H)-diones by T3P^® activation of 3-arylpropiolic acids

• Melanie Denißen,
• Alexander Kraus,
• Guido J. Reiss and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2017, 13, 2340–2351, doi:10.3762/bjoc.13.231

• by an integrating sphere. The emission maximum appears at 468.5 nm, i.e., at the same longest wavelength band as in solution. Therefore, 1H-benzo[f]isoindole-1,3(2H)-diones 4 can be considered as AIE (aggregation induced emission) chromophores [56][57][58]. In comparison to the 1-phenyl-[2,3-c

Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

• Satoru Mori and
• Norio Shibata

Beilstein J. Org. Chem. 2017, 13, 2273–2296, doi:10.3762/bjoc.13.224

• property must be controlled for further applications of phthalocyanines. On the other hand, trifluoroethoxy-substituted phthalocyanines are known to suppress aggregation due to repulsion of the trifluoroethoxy group. Furthermore, the electronic characteristics of phthalocyanines are significantly changed

• . Keywords: aggregation; fluorine; phthalocyanine; subphthalocyanine; trifluoroethoxy; Introduction Phthalocyanines [1][2][3] are analogues of porphyrin condensed with four isoindoline units via a nitrogen atom and exhibit a deep blue color due to their wide 18π electron conjugation. Among them, the most

• the targeted position in the four units using chemical reactions [64][65]. This is because the selective reaction of phthalocyanine is unexplored and removal of byproducts after the reaction is difficult due to its aggregation properties. On the other hand, TFEO-Pcs have high solubility, and chemical

Structural diversity in the host–guest complexes of the antifolate pemetrexed with native cyclodextrins: gas phase, solution and solid state studies

• Magdalena Ceborska,
• Magdalena Zimnicka,
• Aneta Aniela Kowalska,
• Kajetan Dąbrowa and
• Barbara Repeć

Beilstein J. Org. Chem. 2017, 13, 2252–2263, doi:10.3762/bjoc.13.222

• Figure S3 in Supporting Information File 1). Upon titration, to avoid dilution effects and the influence of a possible guest aggregation, the concentration of the guest molecule was kept constant. With the increase of the β-CD concentration the absorbance at the same wavelength decreased, while for γ-CD

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• changes of substances of all states of aggregation due to the influence of mechanical energy”. Moreover, according to IUPAC, a mechano-chemical reaction is a ‘Chemical reaction that is induced by the direct absorption of mechanical energy’ and with a note ‘Shearing, stretching, and grinding are typical

Selective enzymatic esterification of lignin model compounds in the ball mill

• Ulla Weißbach,
• Saumya Dabral,
• Laure Konnert,
• Carsten Bolm and
• José G. Hernández

Beilstein J. Org. Chem. 2017, 13, 1788–1795, doi:10.3762/bjoc.13.173

• were milled (Table 2, entry 3), and formation of phenol was expected as a byproduct of the reaction. Hence, the lower reactivity of 1f could have been a consequence of aggregation of the substrate or possible changes in its conformation. This could have reduced the affinity of CALB for 1f compared to

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

• the nanoparticle synthesis avoiding the aggregation of nanoparticles, which would lower the surface area and increases the diffusion distances in the final particles for Na or Li ions. For the in situ nanoparticle synthesis TiCl4 was dissolved in benzyl alcohol and the block copolymer was added and

Synthesis of oligonucleotides on a soluble support

• Harri Lönnberg

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

• . 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

Glyco-gold nanoparticles: synthesis and applications

• Federica Compostella,
• Olimpia Pitirollo,
• Alessandro Silvestri and
• Laura Polito

Beilstein J. Org. Chem. 2017, 13, 1008–1021, doi:10.3762/bjoc.13.100

• of the magnetic field [41]. AuNP optical properties have been widely exploited in the design of GAuNPs with interesting applications such as the colorimetric biosensors. Based on the LSPR phenomenon, the controlled aggregation and de-assembling of AuNPs is reflected in a detectable variation of the

• surrounding media, which is fundamental in the case of colorimetric bioassays where the NP colloidal stability can strongly influence the state of aggregation and, consequently, the analysis results [43][65][66]. Woods et al., in a recent paper, performed a computational study to evaluate the role of the

• fundamental issue for the efficacy of these nanomaterials [68]. The use of stealth coatings is an effective strategy to decrease or inhibit the non-specific interaction with plasma proteins (the so called “protein corona”), that can modify GAuNP biological identity, affecting aggregation, and cellular uptake

Aggregation behaviour of a single-chain, phenylene-modified bolalipid and its miscibility with classical phospholipids

• Simon Drescher,
• Vasil M. Garamus,
• Christopher J. Garvey,
• Annette Meister and
• Alfred Blume

Beilstein J. Org. Chem. 2017, 13, 995–1007, doi:10.3762/bjoc.13.99

• -Mothes-Str. 3, 06120 Halle (Saale), Germany 10.3762/bjoc.13.99 Abstract In the present work, we describe the synthesis of a single-chain, phenylene-modified bolalipid with two phosphocholine headgroups, PC-C18pPhC18-PC, using a Sonogashira cross-coupling reaction as a key step. The aggregation behaviour

• -C18pPhC18-PC is partially miscible with saturated phosphatidylcholines; however, closed lipid vesicles with an increased thermal stability were not found. Instead, bilayer fragments and disk-like aggregates are formed. Keywords: aggregation behaviour; bolaamphiphiles; bolalipids; membrane lipids; mixing

• dependency on both the aggregation behaviour of the pure bolalipid and the miscibility with bilayer-forming phospholipids. In this study, we investigated the aggregation behaviour of PC-C18pPhC18-PC in aqueous suspension by means of DSC, TEM, Fourier-transform infrared (FTIR) spectroscopy, and small angle

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

• polymer chain, and interaction between the chains (aggregates). There are only minor differences in scattering for concentrations up to 0.02 g/cm3 indicating no significant aggregation between polymer chains with increasing concentration which would lead to highly ordered polymer species. The decrease of

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

• activity of GAT1 protein during purification exists, a near-neutral high-salt buffer containing 4 M MgCl2 (pH 6) (Figure 3) was selected to avoid the irreversible aggregation of GAT1, which may be caused by high pH values. A second purification step with SE-FPLC was performed to remove the eluted

• fusion protein. In this work, the baculovirus expression system was used for the expression of the protein of interest. The full-length GAT1 protein is composed of twelve highly hydrophobic TM domains, which promote strong aggregation behavior of the protein, if it is isolated from the membrane. The

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

• . The UV–vis spectra of annealed films of the polymers at 130 °C show an apparent red shift in the onset absorption because of an increased aggregation of the polymer chains upon heating. The optical band gaps of P1, P2, and P3 were calculated from the onset of the absorption as 1.95 eV, 1.93 eV and

Energy down converting organic fluorophore functionalized mesoporous silica hybrids for monolith-coated light emitting diodes

• Markus Börgardts and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2017, 13, 768–778, doi:10.3762/bjoc.13.76

• aggregation induced self-quenching and singlet oxygen dependent dye degradation can be efficiently prevented [14][15]. By the rigid silica host framework bimolecular photochemical reactions are also suppressed [16]. Additionally, mesoporous materials possess the crucial advantage that they can be synthesized

• loadings of the hybrids are correlated with the surface area of the silica material, typically 700 m2·g−1, self-quenching effects should occur at loadings higher than 10 μmol·g−1 as illustrated in Figure 3 [24]. Although aggregation-induced self-quenching can be prevented by covalently ligating dye

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

• adsorption on the atomically dispersed Pd sites. Electrostatic stabilization of Pd atoms was ascribed to a strong interaction with the nitrogen-coordinating species on the basis of DFT calculations. Effective stabilization also prevented site aggregation, resulting in pretty constant catalytic activity over

Fluorescent carbon dots from mono- and polysaccharides: synthesis, properties and applications

• Stephen Hill and
• M. Carmen Galan

Beilstein J. Org. Chem. 2017, 13, 675–693, doi:10.3762/bjoc.13.67

• increasing the temperature from 15 to 90 °C, 52% of the fluorescence was lost, without any red or blue shift in the emission maximum. The mechanism for this change was also attributed to nanoparticle aggregation, with CD agglomeration occurring at higher temperatures. Two different groups reported, nearly

• green fluorescent N/P-doped CDs with QYs of up to 17% with an excitation independent emission which could be modulated by varying the concentration of Na4P2O7 in the starting mixture. Also, the higher the concentration of pyrophosphate, the less aggregation product was observed. The resultant CDs were

• down hyaluronate (Scheme 15). As hyaluronate is used to stabilise the AuNPs, any enzymatic activity that degrades the polymer would result in AuNP aggregation, which in turn modulates the absorption properties of the AuNPs. The latter has a favourable overlap with the emission spectra of CDs, when

Novel β-cyclodextrin–eosin conjugates

• Gábor Benkovics,
• Damien Afonso,
• András Darcsi,
• Szabolcs Béni,
• Sabrina Conoci,
• Éva Fenyvesi,
• Lajos Szente,
• Milo Malanga and
• Salvatore Sortino

Beilstein J. Org. Chem. 2017, 13, 543–551, doi:10.3762/bjoc.13.52

• -cyclodextrin–EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-cyclodextrin–EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in

• ), to increase the aqueous solubility and to prevent the undesired aggregation of the PS inside the cell. Another advantage offered by the covalently connected CD–PS systems is the encapsulation of hydrophobic photoactivatable drug molecules in the CD cavity, enabling thereby the application of these

• the studied medium and consequently it would lead to false positive results in microscopic studies or in undesired aggregation of the free PS. To circumvent this drawback and to ensure the stability of the dye-appended CD derivatives, different strategies using thioureido [3] or amide [22] connections

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• studies have shown that most of the compounds 26 exhibited a good inhibitory activity against AChE. For instance, compounds 26d and 26i demonstrated IC50 values of 14.8 and 18.6 nM, respectively and a remarkably inhibition of Aβ aggregation. The environmentally benign synthesis of 1-indanones from 3

A chemoselective and continuous synthesis of m-sulfamoylbenzamide analogues

• Arno Verlee,
• Thomas Heugebaert,
• Tom van der Meer,
• Pavel I. Kerchev,
• Frank Van Breusegem and
• Christian V. Stevens

Beilstein J. Org. Chem. 2017, 13, 303–312, doi:10.3762/bjoc.13.33

• ) aggregation [14], which is a major cause of neurodegeneration in Huntington’s disease. Although there are numerous reports available on the study of these analogues, an automated, chemoselective alternative to the synthesis is not yet available. The most common synthetic approach starts from m-(chlorosulfonyl

• -Sulfamoylbenzamides as Sirtuin 2 inhibitors (SIRT2) or suppressor of polyglutamine aggregation (polyQ). Syrris AFRICA system. Screening results of the different conditions for the best chemoselectivity with aniline and azepane as (F2) and (F3), respectively. Screening results of the different conditions for the best

Versatile synthesis of the signaling peptide glorin

• Robert Barnett,
• Daniel Raszkowski,
• Thomas Winckler and
• Pierre Stallforth

Beilstein J. Org. Chem. 2017, 13, 247–250, doi:10.3762/bjoc.13.27

• form a multicellular organism. Eventually, they culminate in fruiting bodies to spread some of the population as dormant spores into the environment. Secondary metabolites often constitute the key signaling molecules in these developmental processes [3][4]. For instance, aggregation of the amoebae is

• signs of aggregation became visible. Cells were washed three times in 17 mM phosphate buffer (pH 6.2) to remove bacteria and suspended at 2 × 107 cells/mL in 17 mM phosphate buffer (pH 6.2) with shaking at 150 rpm. After 1 h of starvation, 1 µM glorin (Phoenix Pharmaceuticals, Burlingame CA, USA

A new class of organogelators based on triphenylmethyl derivatives of primary alcohols: hydrophobic interactions alone can mediate gelation

• Wangkhem P. Singh and
• Rajkumar S. Singh

Beilstein J. Org. Chem. 2017, 13, 138–149, doi:10.3762/bjoc.13.17

• -stacking, donor–acceptor interaction, electrostatic, metal coordination, hydrophobic forces or van der Waals’ interactions [4][5][6]. We know a great deal about the aggregation behaviour of gelator molecules from many studies conducted during the past several years. However, rational design and accurate

Stabilization of nanosized titanium dioxide by cyclodextrin polymers and its photocatalytic effect on the degradation of wastewater pollutants

• Tamás Zoltán Agócs,
• István Puskás,
• Erzsébet Varga,
• Mónika Molnár and
• Éva Fenyvesi

Beilstein J. Org. Chem. 2016, 12, 2873–2882, doi:10.3762/bjoc.12.286

• catalytic activity. The aggregation is a slow process in distilled water, but happens instantly in the presence of salts, e.g., in tap water, surface waters and waste waters. β-CD can be used for stabilization of colloidal TiO2 systems [33] – at least in distilled water – as it is adsorbed on the surface of

• which effectively protects nanoTiO2 in aqueous media against the precipitating effect of different salts in tap water. We used turbidity and light scattering measurements for studying the aggregation behavior of nanoTiO2. In a second step, the photocatalytic properties of the stabilized nanoTiO2

• start to aggregate and form larger particles enhancing the turbidity of dispersion. The turbidity (the haziness of the dispersion caused by particles invisible for the naked eye) was measured to monitor the aggregation of the particles of nanoTiO2. Various monomer and polymer CD derivatives were studied

A self-assembled cyclodextrin nanocarrier for photoreactive squaraine

• Ulrike Kauscher and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2016, 12, 2535–2542, doi:10.3762/bjoc.12.248

• leads to aggregation and inactivation under physiological conditions, causing a reduced production of reactive oxygen species [26]. To overcome this drawback, we considered to immobilize the squaraines onto a platform that provides spatial separation (Figure 1). Our platforms of choice are vesicles self

• applications when a well-known PS, phthalocyanine, was used to decorate the cyclodextrin vesicles [37][38]. The immobilization led to an increased photoactivity of the phthalocyanines due to suppression of aggregation and inactivation of the PS at the surface of the CDVs. In this contribution we show that

• for the CDV without affecting its photochemistry. In addition, it is expected that the aggregation of squaraine will be supressed by immobilization at the CDV surface. Ultimately, the photoactive squaraine can be combined with other functional guests, such as targeting units and tracers, to further

Radical polymerization by a supramolecular catalyst: cyclodextrin with a RAFT reagent

• Kohei Koyanagi,
• Yoshinori Takashima,
• Takashi Nakamura,
• Hiroyasu Yamaguchi and
• Akira Harada

Beilstein J. Org. Chem. 2016, 12, 2495–2502, doi:10.3762/bjoc.12.244

• functions of supramolecular catalysts. CD derivatives are widely used in radical polymerization to dissolve hydrophobic monomers in aqueous solutions [48][49][50][51][52][53][54] and to control the aggregation of polymers [55][56][57][58]. Although supramolecular catalysts with CDs as monomer recognition

Construction of bis-, tris- and tetrahydrazones by addition of azoalkenes to amines and ammonia

• Artem N. Semakin,
• Aleksandr O. Kokuev,
• Yulia V. Nelyubina,
• Alexey Yu. Sukhorukov,
• Petr A. Zhmurov,
• Sema L. Ioffe and
• Vladimir A. Tartakovsky

Beilstein J. Org. Chem. 2016, 12, 2471–2477, doi:10.3762/bjoc.12.241

• integrated with functional fragments upon coordination with metals can undergo significant changes in molecular shape and aggregation state that can be used in the design of smart adaptive materials [1][2]. Some important bis- and trishydrazone ligands used in catalysis, coordination and supramolecular

A direct method for the N-tetraalkylation of azamacrocycles

• Andrew J. Counsell,
• Angus T. Jones,
• Matthew H. Todd and
• Peter J. Rutledge

Beilstein J. Org. Chem. 2016, 12, 2457–2461, doi:10.3762/bjoc.12.239

• be optimised alongside mixing performance [46], and in nanotechnology, where shaking can be used to modulate aggregation so as to favour particular nanostructures [47][48]. Otto and co-workers have investigated the influence of mechanical forces on reactivity in the context of self-replication by