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Search for "network" in Full Text gives 324 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Exploring mechanochemistry to turn organic bio-relevant molecules into metal-organic frameworks: a short review

  • Vânia André,
  • Sílvia Quaresma,
  • João Luís Ferreira da Silva and
  • M. Teresa Duarte

Beilstein J. Org. Chem. 2017, 13, 2416–2427, doi:10.3762/bjoc.13.239

Graphical Abstract
  • bioactive molecules is achieved by degradation of the framework, ii) no multistep synthesis is required as the molecules are part of the matrix itself, iii) synergetic effects between the active molecule and the metal may be explored, and iv) co-delivery of drugs is possible if a porous network is built
  • to approximately 80 °C. Both BioMOFs were obtained recurring to manual mechanochemistry. Due to the possibility of synergic effects with Ag+, a known antimicrobial agent, the new network with 4-aminosalicylic acid and silver is highly interesting, as it represents a promising candidate to future
  • and this is certainly an expanding area in the field of organic coordination chemistry. a) Detailed supramolecular packing of a gabapentin–Er network; b) view along the b-axis of the supramolecular packing of a gabapentin–Ce network; c) view of a GBP–Y network showing an infinite 1D chain; d
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Published 14 Nov 2017

Solvent-free copper-catalyzed click chemistry for the synthesis of N-heterocyclic hybrids based on quinoline and 1,2,3-triazole

  • Martina Tireli,
  • Silvija Maračić,
  • Stipe Lukin,
  • Marina Juribašić Kulcsár,
  • Dijana Žilić,
  • Mario Cetina,
  • Ivan Halasz,
  • Silvana Raić-Malić and
  • Krunoslav Užarević

Beilstein J. Org. Chem. 2017, 13, 2352–2363, doi:10.3762/bjoc.13.232

Graphical Abstract
  • notation as R22(18) [54]. Although the same motif formed by the analogous hydrogen bond is observed in other three structures (Table S3, Supporting Information File 1), the final supramolecular structures of 5–8 differ, from one-dimensional chains to three-dimensional network. It should be mentioned that
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Published 06 Nov 2017

Synthesis of ergostane-type brassinosteroids with modifications in ring A

  • Vladimir N. Zhabinskii,
  • Darya A. Osiyuk,
  • Yuri V. Ermolovich,
  • Natalia M. Chaschina,
  • Tatsiana S. Dalidovich,
  • Miroslav Strnad and
  • Vladimir A. Khripach

Beilstein J. Org. Chem. 2017, 13, 2326–2331, doi:10.3762/bjoc.13.229

Graphical Abstract
  • moieties, exhibit hormonal activity in plants, whereas other BS are considered to be either biosynthetic precursors or metabolites of the “real” phytohormones [2]. All these compounds are part of a multidimensional biosynthetic metabolic network, the functioning of which is still far from being completely
  • understood. Evidently, the identification of as much as possible elements of this network would contribute to its better knowledge. Because of the extremely low BS content in natural sources, studies on their identification almost always included a preliminary chemical synthesis of the compounds in question
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Published 02 Nov 2017

A mechanochemical approach to access the proline–proline diketopiperazine framework

  • Nicolas Pétry,
  • Hafid Benakki,
  • Eric Clot,
  • Pascal Retailleau,
  • Farhate Guenoun,
  • Fatima Asserar,
  • Chakib Sekkat,
  • Thomas-Xavier Métro,
  • Jean Martinez and
  • Frédéric Lamaty

Beilstein J. Org. Chem. 2017, 13, 2169–2178, doi:10.3762/bjoc.13.217

Graphical Abstract
  • . Transition state structures with combined implicit (SMD model) and explicit inclusion of the solvent were thus searched for. The geometry of 16a allowed the creation of a network of stabilizing interactions between an explicit methanol solvent molecule and both the N–H proton and the OMe group (N–H···O
  • the geometry of 15a-solv (Figure 2) had the stereochemistry expected for 15a (Scheme 5). The geometry of 16b did not allow creating a similar network of H-bonding interactions when one explicit molecule of methanol was considered. The N–H bond is pointed in a direction of space remote from the methoxy
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Published 19 Oct 2017

Solid-state studies and antioxidant properties of the γ-cyclodextrin·fisetin inclusion compound

  • Joana M. Pais,
  • Maria João Barroca,
  • Maria Paula M. Marques,
  • Filipe A. Almeida Paz and
  • Susana S. Braga

Beilstein J. Org. Chem. 2017, 13, 2138–2145, doi:10.3762/bjoc.13.212

Graphical Abstract
  • and C4 carbons, multiplicity is associated with differences in the conformation about the α(1→4) linkages, while carbons positioned closer to the rims, such as is the case for C6, are more sensitive to ambient changes arising from hydration water molecules and the hydrogen-bonding network [33][34
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Published 13 Oct 2017

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

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  • viscosity of the network as shown by ITC, 1H NMR and UV–vis spectroscopy, and rheological studies. Such networks potentially form a basis for the design of controlled drug release systems. Keywords: controlled release; cyclodextrin; network; poly(acrylate); self-assembly; Introduction The formation of
  • ] and PAAADddn [15], respectively, where the poly(acrylate) is of 250 kDa average molecular weight prior to substitution (Figure 1). The network formation is driven by the β-CDen substituents complexing the adamantyl substituents, ADen, ADhn or ADddn, to form cross-links between the PAAβ-CDen strands
  • substitution of PAAβ-CDen. Thus, when host–guest complexation between the poly(acrylate) substituents of the network is complete, ca. two thirds of the β-CDen substituents remain available to complex other hydrophobic species exemplified by the dyes methyl red, MR, methyl orange, MO, and ethyl orange, EO
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Published 07 Sep 2017

A recursive microfluidic platform to explore the emergence of chemical evolution

  • David Doran,
  • Marc Rodriguez-Garcia,
  • Rebecca Turk-MacLeod,
  • Geoffrey J. T. Cooper and
  • Leroy Cronin

Beilstein J. Org. Chem. 2017, 13, 1702–1709, doi:10.3762/bjoc.13.164

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  • evolution in droplets Here, we propose a system for facilitating chemical evolution in populations of co-incubating aqueous, single emulsion microfluidic droplets. Each microdroplet can be considered an autonomous microreactor, loaded with a self-propagating chemical reaction network. However, it has been
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Published 17 Aug 2017

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

Graphical Abstract
  • have been involved to convert a dynamic, molecularly diverse chemical environment into a coherent, interconnected network of chemical processes, leading ultimately to contemporary biochemistry. Even when a deconstructive (top-down) approach, i.e., the attempt to simplify the current biochemistry
  • reports on chemical systems, we will highlight the potential of the “chemical system” approach for the investigation of the origin of pre-cellular systems and protocells. What are chemical systems? Chemical systems are defined here as chemical mixtures comprising a network or set of interacting molecules
  • be large enough to couple a proton gradient to a reaction network (presumably as long as its dynamic stability is on a similar scale or longer to reaction rates). Interestingly, while the presence of amphiphile structures acts to solubilize the highly hydrophobic PAHs, hence their light harvesting
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Published 07 Aug 2017

Grip on complexity in chemical reaction networks

  • Albert S. Y. Wong and
  • Wilhelm T. S. Huck

Beilstein J. Org. Chem. 2017, 13, 1486–1497, doi:10.3762/bjoc.13.147

Graphical Abstract
  • systems within a synthetic chemical framework. Living systems rely on complex networks of chemical reactions to control the concentration of molecules in space and time. Despite the enormous complexity in biological networks, it is possible to identify network motifs that lead to functional outputs such
  • chemical entities on the properties of the network as a whole. Ultimately, this approach should allow us to not only understand such complex networks but also to guide and control their behavior. Keywords: chemical reaction network; complexity; dissipative systems; network motifs; out-of-equilibrium
  • the predictability and perhaps the possibility to influence the dynamics of change, but science has yet to find an answer to this complexity [15]. One of the ultimate aims for systems like a living cell, is to understand how the interplay between molecular level events and network topology determines
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Published 28 Jul 2017

Mechanochemistry-assisted synthesis of hierarchical porous carbons applied as supercapacitors

  • Desirée Leistenschneider,
  • Nicolas Jäckel,
  • Felix Hippauf,
  • Volker Presser and
  • Lars Borchardt

Beilstein J. Org. Chem. 2017, 13, 1332–1341, doi:10.3762/bjoc.13.130

Graphical Abstract
  • hierarchical micro-meso-macroporous pore systems, facilitate fast ion transport through the carbon pore network [20][21]. Therefore, synthesis approaches leading to such pore systems are highly desirable to improve the electrochemical performance of carbon supercapacitors. A well-established strategy for
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Published 06 Jul 2017

Biomimetic molecular design tools that learn, evolve, and adapt

  • David A Winkler

Beilstein J. Org. Chem. 2017, 13, 1288–1302, doi:10.3762/bjoc.13.125

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  • future impact. It introduces the most common type of algorithm, machine learning. A discussion of a very useful machine-learning algorithm, the neural network follows, and problems that often arise in their use, and solutions to these difficulties described. A new type of deep learning neural network
  • paradigm shifting new variants called deep learning. We provide a brief summary of these types of machine learning algorithms to assist those organic chemists who are not familiar with them. Traditional backpropagation algorithm A common machine learning algorithm is the backpropagation neural network
  • used to generate the output. Initially the weights are set to random numbers. During training, the difference between the predicted outputs from the neural network and the measured properties of the molecules used to train the network generates errors. These errors are propagated backwards using the
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Published 29 Jun 2017

Strategies toward protecting group-free glycosylation through selective activation of the anomeric center

  • A. Michael Downey and
  • Michal Hocek

Beilstein J. Org. Chem. 2017, 13, 1239–1279, doi:10.3762/bjoc.13.123

Graphical Abstract
  • sequentially deoxygenated sucrose derivatives and quantified H-to-D isotope exchange effects (from the deuterated solvent) using 1H NMR techniques. They concluded that it is the complex hydrogen-bonding network present in sucrose that played the key role in determining the reactivity and selectivity of the
  • reaction. Removal of the OH groups at positions C2 of Glc, C1′and C3′-Fru resulted in no conversion at all. The authors demonstrated that not only these deoxygenations change the hydrogen-bonding network but also have a very large effect on the overall nucleophilicity of the disaccharide and its
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Published 27 Jun 2017

Sugar-based micro/mesoporous hypercross-linked polymers with in situ embedded silver nanoparticles for catalytic reduction

  • Qing Yin,
  • Qi Chen,
  • Li-Can Lu and
  • Bao-Hang Han

Beilstein J. Org. Chem. 2017, 13, 1212–1221, doi:10.3762/bjoc.13.120

Graphical Abstract
  • a polymer network with a high SSA [6], HCPs with knitted building blocks have been widely utilized because of their high SSA [7][8], mild synthesis conditions [9][10], and wide range of monomers [11]. The porosity and functionality of HCPs is highly dependent on the core structural monomers [12][13
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Published 22 Jun 2017

Towards open-ended evolution in self-replicating molecular systems

  • Herman Duim and
  • Sijbren Otto

Beilstein J. Org. Chem. 2017, 13, 1189–1203, doi:10.3762/bjoc.13.118

Graphical Abstract
  • synthetic autocatalytic network that shows two significantly distinct steady states depending on the history of the system [39]. Depending on the initial concentration of replicator molecules provided to the system, the system will reach either a low or a high steady state replicator concentration
  • in which no novel forms of the replicator can be explored anymore. 3.5 Cooperative catalytic system The concept of such a cross-replicating system can be readily extended to higher order systems, involving three, four or even more components. Eventually, one could envision an entire network of cross
  • , proving that the system replicates in a cooperative manner. Interestingly, it was shown that in isolation the autocatalytic replicators (with the IGS programmed to recognize itself) replicated faster than the cross-catalytic system, whereas in a mixture of all different components the cooperative network
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Published 21 Jun 2017

Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience

  • Serge Pérez and
  • Daniele de Sanctis

Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114

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  • the key to ascertain the processes of biosynthesis. Cellulosic materials in nature often have many levels of structural complexity, whose organization depends on the source organism. In wood, a cohesive interlaced network of crystalline microfibrils of cellulose composes a first level of interacting
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Published 14 Jun 2017

From chemical metabolism to life: the origin of the genetic coding process

  • Antoine Danchin

Beilstein J. Org. Chem. 2017, 13, 1119–1135, doi:10.3762/bjoc.13.111

Graphical Abstract
  • within the cytoplasm as a Peano surface, thus solving the 2D/3D dilemma. It is therefore natural to assume that the first cells harboured an internal membrane network [17] coupled to peptide metabolism. Finally, an essential feature of compartmentalisation is more subtle: A cell must give birth to
  • as templates. The algorithm that drives duplication of the centriole is a piece of information with delayed implementation, associated to a specific set of genes that are replicated when the cell reproduces. Protein-network replication might have predated replication mediated by nucleic acids, via
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Published 12 Jun 2017

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

Graphical Abstract
  • molecules displayed on the metallic surface. In particular, an in vitro study performed by Mitragotri and co-workers reported that the endothelial targeting specificity could be enhanced by modulating the NP shape. By using a microfluidic synthetic vascular network the authors demonstrated that rod-shaped
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Published 24 May 2017

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

Graphical Abstract
  • suspended in water, the formation of a dense network of nanofibres and, as a consequence, a clear and transparent hydrogel is observed [25]. The nanofibres have a thickness of about 6 nm, corresponding to the length of a PC-C32-PC molecule. Due to the bulky PC headgroup, the PC-C32-PC molecules are arranged
  • of aggregates, samples for TEM were prepared below the first transition as well as between the first and the second transition of PC-C18pPhC18-PC. At about 7 °C, the TEM image depicts a dense network of long nanofibres (A). The morphology of these fibres changes with increasing temperature. At 36 °C
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Published 23 May 2017

Automating multistep flow synthesis: approach and challenges in integrating chemistry, machines and logic

  • Chinmay A. Shukla and
  • Amol A. Kulkarni

Beilstein J. Org. Chem. 2017, 13, 960–987, doi:10.3762/bjoc.13.97

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Published 19 May 2017

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

Graphical Abstract
  • catalyst productivity and selectivity [105][106]. Particularly, monoliths featuring a 3D isotropic, hierarchically porous network of narrowly size distributed, interconnected macropores (1–30 μm) and mesopores within the struts (6–50 nm) have shown a unique hydrodynamic behavior in the liquid phase [107
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Published 20 Apr 2017

Inclusion complexes of β-cyclodextrin with tricyclic drugs: an X-ray diffraction, NMR and molecular dynamics study

  • Franca Castiglione,
  • Fabio Ganazzoli,
  • Luciana Malpezzi,
  • Andrea Mele,
  • Walter Panzeri and
  • Giuseppina Raffaini

Beilstein J. Org. Chem. 2017, 13, 714–719, doi:10.3762/bjoc.13.70

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  • antiparallel columns along the crystallographic b axis. Within each column, the molecules are linked by hydrogen bonding involving both the macrocycles and the guest molecules, while interactions between macrocycles link adjacent columns. A large network of H-bonds involving the water molecules contribute to
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Published 13 Apr 2017

How and why kinetics, thermodynamics, and chemistry induce the logic of biological evolution

  • Addy Pross and
  • Robert Pascal

Beilstein J. Org. Chem. 2017, 13, 665–674, doi:10.3762/bjoc.13.66

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  • relative free energies of reactant (R) and products (P1 and P2). Under kinetic control, P2 would be favoured over P1. Evolution of an autocatalytic network involving a parasite. R: resource; A: autocatalyst; B: predator autocatalyst. Numerical simulation of the system of Figure 3 (k0 = 0.01 M min−1, k1
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Published 07 Apr 2017

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

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  • synthesis of the [14C]indene 176, which was next applied for the examination of the indene bioconversion network expressed in Rhodococcus sp. KY1 [79]. The [14C]1-indanone 175 was obtained in the one-pot synthesis involving the Friedel–Crafts acylation of [14C]benzene 173 with chloropropionic acid chloride
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Published 09 Mar 2017

Highly reactive, liquid diacrylamides via synergistic combination of spatially arranged curing moieties

  • Maximilian Maier,
  • Magnus S. Schmidt,
  • Markus Ringwald and
  • Christoph P. Fik

Beilstein J. Org. Chem. 2017, 13, 372–383, doi:10.3762/bjoc.13.40

Graphical Abstract
  • elucidated the underlying polymerization mechanism. Mechanical testing of the obtained polymers exhibited gradual differences in network densities, depending on the intramolecular arrangement and number of functional groups. Overall, a general building principle for highly reactive, liquid diacrylamides via
  • initiate the lactam formation with the internal butene group, whereas there is only one favorable orientation for the external allyl group. Polymer network properties To assess the influence of functionalities on the network densities of the obtained polymers, mechanical data of rod-like samples according
  • thus highest apparent network density. This means that ring formation, which in principle should reduce the amount of covalent network points in the cured material, is superimposed by effects of conversion, entanglement and rigidity of the formed polymer. The decreasing trend of flexural modulus from 1
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Published 27 Feb 2017

Efficient access to β-vinylporphyrin derivatives via palladium cross coupling of β-bromoporphyrins with N-tosylhydrazones

  • Vinicius R. Campos,
  • Ana T. P. C. Gomes,
  • Anna C. Cunha,
  • Maria da Graça P. M. S. Neves,
  • Vitor F. Ferreira and
  • José A. S. Cavaleiro

Beilstein J. Org. Chem. 2017, 13, 195–202, doi:10.3762/bjoc.13.22

Graphical Abstract
  • . Acknowledgments We would like to thank the University of Aveiro, the “Fundação para a Ciência e a Tecnologia” (FCT), the European Union, QREN, FEDER and COMPETE for funding the QOPNA research unit (project PEst-C/QUI/UI0062/2013) and the Portuguese National NMR Network (RNRMN). A. T. P. C. Gomes also thanks FCT
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Published 30 Jan 2017
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