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Search for "complexity" in Full Text gives 354 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Silver-catalyzed synthesis of β-fluorovinylphosphonates by phosphonofluorination of aromatic alkynes

  • Yajing Zhang,
  • Qingshan Tian,
  • Guozhu Zhang and
  • Dayong Zhang

Beilstein J. Org. Chem. 2020, 16, 3086–3092, doi:10.3762/bjoc.16.258

Graphical Abstract
  • vinylphosphonates from simple and commercially available alkynes proceeds under mild conditions with high stereoselectivity, and thus enabling the rapid construction of molecular complexity. Results and Discussion We investigated the reaction of phenylacetylene (1a), Selectfluor®, and diethyl phosphite to afford β
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Published 18 Dec 2020

Semiautomated glycoproteomics data analysis workflow for maximized glycopeptide identification and reliable quantification

  • Steffen Lippold,
  • Arnoud H. de Ru,
  • Jan Nouta,
  • Peter A. van Veelen,
  • Magnus Palmblad,
  • Manfred Wuhrer and
  • Noortje de Haan

Beilstein J. Org. Chem. 2020, 16, 3038–3051, doi:10.3762/bjoc.16.253

Graphical Abstract
  • high complexity of glycosylation itself, data analysis is further complicated by interfering background signals from biological matrices and isomeric and near-isobaric ambiguities resulting from combinations of monosaccharides, adducts, amino acids, and amino acid modifications [10][11]. Efforts have
  • this, a sample containing immunoglobulins G and A (IgG and IgA), simultaneously captured from human plasma, was chosen. This sample showed a considerable level of complexity due to the presence of multiple glycoproteins of interest and cocaptured (glyco)proteins from the plasma. The tools included
  • implications on the IgA glycoprofiling accuracy. Further elaboration of the Cys-containing peptides, including modifications and correct glycan composition identifications, were considered beyond the scope of this study due to the largely increased complexity. Hence, the applicability of the proposed
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Published 11 Dec 2020

Three-component reactions of aromatic amines, 1,3-dicarbonyl compounds, and α-bromoacetaldehyde acetal to access N-(hetero)aryl-4,5-unsubstituted pyrroles

  • Wenbo Huang,
  • Kaimei Wang,
  • Ping Liu,
  • Minghao Li,
  • Shaoyong Ke and
  • Yanlong Gu

Beilstein J. Org. Chem. 2020, 16, 2920–2928, doi:10.3762/bjoc.16.241

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  • and (ii) permits to synthesize pyrroles with a high potential of molecular diversity and complexity. However, to date, the productivity for creating molecular diversity and complexity has yet to be fully displayed. In addition, some of the reported approaches were established on the basis of using
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Letter
Published 30 Nov 2020

One-pot multicomponent green Hantzsch synthesis of 1,2-dihydropyridine derivatives with antiproliferative activity

  • Giovanna Bosica,
  • Kaylie Demanuele,
  • José M. Padrón and
  • Adrián Puerta

Beilstein J. Org. Chem. 2020, 16, 2862–2869, doi:10.3762/bjoc.16.235

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  • under argon, they obtained a mixture of the two regioisomers (1,4-DHP/1,2-DHP 32:68), proving further the complexity of this reaction [19]. Therefore, continuing our studies for the development and application of environmentally friendly methodologies for multicomponent reactions [20], we attempted to
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Published 24 Nov 2020

On the mass spectrometric fragmentations of the bacterial sesterterpenes sestermobaraenes A–C

  • Anwei Hou and
  • Jeroen S. Dickschat

Beilstein J. Org. Chem. 2020, 16, 2807–2819, doi:10.3762/bjoc.16.231

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  • complicated cases, as was exemplified for the side products of bacterial 2-methylisoborneol synthases [22], but in general the structural complexity of terpenes does not allow for such approaches. Nevertheless, more knowledge about the MS fragmentation reactions of terpenes is desirable, but represents a
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Published 19 Nov 2020

A heterobimetallic tetrahedron from a linear platinum(II)-bis(acetylide) metalloligand

  • Matthias Hardy,
  • Marianne Engeser and
  • Arne Lützen

Beilstein J. Org. Chem. 2020, 16, 2701–2708, doi:10.3762/bjoc.16.220

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  • sophisticated cage-in-ring structures [6][7], interlocked rings [8] and catenanes [9][10][11][12] or giant spheres [13][14]. Increasing the structural complexity, however, usually implies growing synthetic efforts that have to be made to obtain the necessary organic ligands [15][16][17]. A great way to simplify
  • complexity with homometallic assemblies becomes increasingly difficult to achieve. An approach to tackle these limitations is the use of not only one, but two different types of metal cations to form heterobimetallic aggregates [24][25][26]. Introducing two different types of metal cations within one
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Published 03 Nov 2020

Vicinal difluorination as a C=C surrogate: an analog of piperine with enhanced solubility, photostability, and acetylcholinesterase inhibitory activity

  • Yuvixza Lizarme-Salas,
  • Alexandra Daryl Ariawan,
  • Ranjala Ratnayake,
  • Hendrik Luesch,
  • Angela Finch and
  • Luke Hunter

Beilstein J. Org. Chem. 2020, 16, 2663–2670, doi:10.3762/bjoc.16.216

Graphical Abstract
  • predominate. Of course, the contiguous positioning of the F–C–C–F and F–C–C=O moieties within the same molecule (2) means that these moieties would not function independently, but rather would likely influence one another, adding another layer of complexity. Finally, it is interesting to consider whether the
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Published 28 Oct 2020

Leveraging glycomics data in glycoprotein 3D structure validation with Privateer

  • Haroldas Bagdonas,
  • Daniel Ungar and
  • Jon Agirre

Beilstein J. Org. Chem. 2020, 16, 2523–2533, doi:10.3762/bjoc.16.204

Graphical Abstract
  • complexity of glycans in glycoproteins have been, and currently remain, significant challenges in structural biology. These aspects present unique problems to the two most prolific techniques: X-ray crystallography and cryo-electron microscopy. At the same time, advances in mass spectrometry have made it
  • databases can usually be interrogated using textual or graphical notations that describe the glycan sequence. However, due to the glycan complexity and the incremental nature of the different glycomics projects, numerous notations have been developed over the years – e.g., CarbBank [48] utilized CCSD [48
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Published 09 Oct 2020

Dawn of a new era in industrial photochemistry: the scale-up of micro- and mesostructured photoreactors

  • Emine Kayahan,
  • Mathias Jacobs,
  • Leen Braeken,
  • Leen C.J. Thomassen,
  • Simon Kuhn,
  • Tom van Gerven and
  • M. Enis Leblebici

Beilstein J. Org. Chem. 2020, 16, 2484–2504, doi:10.3762/bjoc.16.202

Graphical Abstract
  • sequestration [7]. Still, photochemistry has not been exploited much in industry since the distribution of light inside a photoreactor brings a lot of complexity to the reactor design. Unlike thermochemical reactions, it is not feasible to scale up photoreactions by increasing the dimensions of the reactor due
  • successful scale-up strategies in literature. Design considerations The complexity of the photochemical processes leads to significant challenges in the photoreactor design. In addition to the general reactor design considerations, such as the selection of a suitable reactor material and geometry, the
  • energy efficiency. In addition, the solvent should not absorb light strongly nor be a quencher of the photoreaction. In order to avoid excessive heating of the light source, cooling systems might be necessary. The distribution of light inside the reactor brings a lot of complexity into the design. Since
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Published 08 Oct 2020

Conformational preferences of fluorine-containing agrochemicals and their implications for lipophilicity prediction

  • Daniela Rodrigues Silva,
  • Joyce K. Daré and
  • Matheus P. Freitas

Beilstein J. Org. Chem. 2020, 16, 2469–2476, doi:10.3762/bjoc.16.200

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  •  5b). Most tools for predicting physicochemical properties are based on the additive contributions of polarity from atoms or chemical groups instead of considering the overall molecular polarity (μ) [27]. The predictive ability of these methods for compounds with higher structural complexity have been
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Published 05 Oct 2020

Computational tools for drawing, building and displaying carbohydrates: a visual guide

  • Kanhaya Lal,
  • Rafael Bermeo and
  • Serge Perez

Beilstein J. Org. Chem. 2020, 16, 2448–2468, doi:10.3762/bjoc.16.199

Graphical Abstract
  • a continuous development and evolution of the description of monosaccharides [2]. Glycans are puzzles to many chemists, and biologists as well as bioinformaticians. This complexity occurs at different levels (which makes it incremental). Amongst the most recognisable “sugars”, glucose is merely one
  • together either linearly or branched); (ii) polysaccharides (for glycan chains composed of more than ten monosaccharides); (iii) glycoconjugates (where the glycan chains are covalently linked to proteins (glycoproteins), lipids (glycolipids). The complexity of glycans is a consequence of their branched
  • structure and the range of building blocks available. Other levels of complexity include the nature of the glycosidic linkage (anomeric configuration, position and angles), the number of repeating units (polysaccharides) as well as the substitutions of the monosaccharides. Regardless of the different
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Published 02 Oct 2020
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  • of such databases requires significant investment in time and energy but once done it is expected that they will have far-reaching utility in the long run. An important point to keep in mind in extending synthesis chains to first generation feedstocks of simple chemical complexity is that
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Published 25 Sep 2020

Design and synthesis of a bis-macrocyclic host and guests as building blocks for small molecular knots

  • Elizabeth A. Margolis,
  • Rebecca J. Keyes,
  • Stephen D. Lockey IV and
  • Edward E. Fenlon

Beilstein J. Org. Chem. 2020, 16, 2314–2321, doi:10.3762/bjoc.16.192

Graphical Abstract
  • trefoil knots have been prepared with an all-hydrocarbon example by the Itami group [7] and the synthesis of a single enantiomer by Leigh’s group [8]. Complexity has also been achieved with recent work showing that eight-crossing knots [9][10][11] and a nine-crossing composite knot can be synthesized [12
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Published 18 Sep 2020

Tools for generating and analyzing glycan microarray data

  • Akul Y. Mehta,
  • Jamie Heimburg-Molinaro and
  • Richard D. Cummings

Beilstein J. Org. Chem. 2020, 16, 2260–2271, doi:10.3762/bjoc.16.187

Graphical Abstract
  • intricacies involved at multiple levels. Unlike DNA and proteins, glycans are neither linear nor template driven, making their structures computationally taxing. In addition, the complexity is compounded by the sample and experimental meta data associated with the glycan microarray experiment. The following
  • comparison of glycan microarray data. We identify a variety of glycan microarray repositories where interested readers can find microarray data to build new software. We also highlight manual and automated data analysis tools. One must always be aware that the intrinsic complexity of the multistep process of
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Published 10 Sep 2020

Naphthalene diimide bis-guanidinio-carbonyl-pyrrole as a pH-switchable threading DNA intercalator

  • Poulami Jana,
  • Filip Šupljika,
  • Carsten Schmuck and
  • Ivo Piantanida

Beilstein J. Org. Chem. 2020, 16, 2201–2211, doi:10.3762/bjoc.16.185

Graphical Abstract
  • molecules were dyes used for the DNA/RNA labelling or even monitoring or influencing DNA/RNA function [3][4]. However, due to the complexity of DNA-coded or RNA-coded processes, also including epigenetics, there is permanent need for novel dyes, differing in selectivity, colour, or method of monitoring [5
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Published 08 Sep 2020

GlypNirO: An automated workflow for quantitative N- and O-linked glycoproteomic data analysis

  • Toan K. Phung,
  • Cassandra L. Pegg and
  • Benjamin L. Schulz

Beilstein J. Org. Chem. 2020, 16, 2127–2135, doi:10.3762/bjoc.16.180

Graphical Abstract
  • complexity of glycan heterogeneity requires that downstream analysis often involves manual processing in addition to standard informatics workflows. Here, we developed and used GlypNirO, an automated bioinformatic workflow for label-free quantitative N- and O-glycoproteomics that focuses on improving
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Published 01 Sep 2020

Clustering and curation of electropherograms: an efficient method for analyzing large cohorts of capillary electrophoresis glycomic profiles for bioprocessing operations

  • Ian Walsh,
  • Matthew S. F. Choo,
  • Sim Lyn Chiin,
  • Amelia Mak,
  • Shi Jie Tay,
  • Pauline M. Rudd,
  • Yang Yuansheng,
  • Andre Choo,
  • Ho Ying Swan and
  • Terry Nguyen-Khuong

Beilstein J. Org. Chem. 2020, 16, 2087–2099, doi:10.3762/bjoc.16.176

Graphical Abstract
  • . This can be caused by a combination of sample complexity, temperature, pH, day of analysis, and other physicochemical fluctuations during the operation of the analysis. Although GU calculation can help solve this for the qualitative analysis, there is still difficulty automating peak picking due to
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Published 27 Aug 2020

How and why plants and human N-glycans are different: Insight from molecular dynamics into the “glycoblocks” architecture of complex carbohydrates

  • Carl A. Fogarty,
  • Aoife M. Harbison,
  • Amy R. Dugdale and
  • Elisa Fadda

Beilstein J. Org. Chem. 2020, 16, 2046–2056, doi:10.3762/bjoc.16.171

Graphical Abstract
  • invoked when discussing other biopolymers or complex carbohydrates. In the specific case of glycans, the structural complexity, in terms of the diversity of monosaccharides, the linkages’ stereochemistry and the branched scaffolds, makes the already difficult case even more intricate. Nevertheless, the
  • , the functionalization of the arms to include terminal β(1-3)-Gal reduces the occurrence of this event down to around 5%, see Table S6 in Supporting Information File 1. Terminal LeA and LeX motifs in plant N-glycans: To understand how an increased complexity on the arms would affect the dynamics of the
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Published 21 Aug 2020

Polarity effects in 4-fluoro- and 4-(trifluoromethyl)prolines

  • Vladimir Kubyshkin

Beilstein J. Org. Chem. 2020, 16, 1837–1852, doi:10.3762/bjoc.16.151

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  • . Nonetheless, it is barely conclusive to approach interaction of complex molecules with solvents using net dipole alone. For example, even for the relatively simple molecules like 1–4, the net dipole would not adequately represent neither the complexity of the interaction network within the molecule, nor
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Published 23 Jul 2020

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

  • Lucas Guillemard and
  • Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

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  • routes to afford molecular complexity from simple precursors, while concomitantly limiting the number of steps and waste generation. Following this general key objective, the landscape of organic synthesis has been clearly changed by the development of ecofriendly methodologies such as metal-catalyzed C
  • motif, have also attracted significant scientific interest [103]. Such couplings allowed constructing molecular complexity from very simple arenes such as benzene, toluene or mesitylene. However, such transformations frequently required rather harsh reaction conditions as well as the addition of strong
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Published 21 Jul 2020

Synthesis of Streptococcus pneumoniae serotype 9V oligosaccharide antigens

  • Sharavathi G. Parameswarappa,
  • Claney L. Pereira and
  • Peter H. Seeberger

Beilstein J. Org. Chem. 2020, 16, 1693–1699, doi:10.3762/bjoc.16.140

Graphical Abstract
  • escape the host immune response [1][7]. These polysaccharides of SP consist of repeating units (RU) that range from di- to heptasaccharides that may be branched and/or charged [8]. Modifications such as O-acetylation, phosphorylation, and sulfation further increase CPS complexity. Many bacterial
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Published 15 Jul 2020

A dynamic combinatorial library for biomimetic recognition of dipeptides in water

  • Florian Klepel and
  • Bart Jan Ravoo

Beilstein J. Org. Chem. 2020, 16, 1588–1595, doi:10.3762/bjoc.16.131

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  • compounds could not be achieved due to the high complexity of the library and the structural similarity of its members. Hence ESI-TOF mass spectrometry data can be interpreted qualitatively but not quantitatively. A full reference sample is shown in Figure 1. Each chromatogram represents a single
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Published 02 Jul 2020

Disposable cartridge concept for the on-demand synthesis of turbo Grignards, Knochel–Hauser amides, and magnesium alkoxides

  • Mateo Berton,
  • Kevin Sheehan,
  • Andrea Adamo and
  • D. Tyler McQuade

Beilstein J. Org. Chem. 2020, 16, 1343–1356, doi:10.3762/bjoc.16.115

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  • ]. These systems are designed to achieve a generality of operation, and this comes with an increase in the cost and complexity of the instruments. Our on-demand approach targets the opposite end of the equipment design spectrum; it requires a low-cost systems designed to carry out only a few specific
  • functions in a safe and robust manner. It also demands to be low-cost in order to have any potential for real-world applications. In other words, to achieve the set goals, innovation is needed to reduce the complexity/expense of (1) pumps; (2) reactors; (3) valves; (4) fittings, and (5) chemical containers
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Published 19 Jun 2020

Highly selective Diels–Alder and Heck arylation reactions in a divergent synthesis of isoindolo- and pyrrolo-fused polycyclic indoles from 2-formylpyrrole

  • Carlos H. Escalante,
  • Eder I. Martínez-Mora,
  • Carlos Espinoza-Hicks,
  • Alejandro A. Camacho-Dávila,
  • Fernando R. Ramos-Morales,
  • Francisco Delgado and
  • Joaquín Tamariz

Beilstein J. Org. Chem. 2020, 16, 1320–1334, doi:10.3762/bjoc.16.113

Graphical Abstract
  • with the complexity of its structures [11][19][20][21][22][23][24][25][26][27]. The intramolecular Heck arylation coupling reaction is among the most useful strategies for the construction of these compounds (Scheme 1) [11][21]. For example, isoindolo[2,1-a]indoles 6 have been prepared by the
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Published 17 Jun 2020

Oxime radicals: generation, properties and application in organic synthesis

  • Igor B. Krylov,
  • Stanislav A. Paveliev,
  • Alexander S. Budnikov and
  • Alexander O. Terent’ev

Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107

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  • , arylalkyl, and diaryl oxime radicals was also studied by EPR spectroscopy [53]. Radicals were generated under inert atmosphere directly in the EPR cavity by photolysis of the added di-tert-butyl peroxide (Scheme 1). The authors pointed out the complexity of the processes of iminoxyl radicals’ decomposition
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Published 05 Jun 2020
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