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Search for "time-of-flight" in Full Text gives 91 result(s) in Beilstein Journal of Organic Chemistry.

Access to highly substituted oxazoles by the reaction of α-azidochalcone with potassium thiocyanate

  • Mysore Bhyrappa Harisha,
  • Pandi Dhanalakshmi,
  • Rajendran Suresh,
  • Raju Ranjith Kumar and
  • Shanmugam Muthusubramanian

Beilstein J. Org. Chem. 2020, 16, 2108–2118, doi:10.3762/bjoc.16.178

Graphical Abstract
  • indicated by the following symbols: s (singlet), d (doublet), t (triplet), m (multiplet), dd (doublet of doublets), td (triplet of doublets), ddd (doublet of doublets of doublets), bs (broad singlet). Mass spectra were measured with Micromass Q-Time of flight (HRESIMS). General procedure for the preparation
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Published 31 Aug 2020

One-pot synthesis of oxazolidinones and five-membered cyclic carbonates from epoxides and chlorosulfonyl isocyanate: theoretical evidence for an asynchronous concerted pathway

  • Esra Demir,
  • Ozlem Sari,
  • Yasin Çetinkaya,
  • Ufuk Atmaca,
  • Safiye Sağ Erdem and
  • Murat Çelik

Beilstein J. Org. Chem. 2020, 16, 1805–1819, doi:10.3762/bjoc.16.148

Graphical Abstract
  • 100 MHz, respectively, and NMR shifts are presented as δ in ppm. Elemental analyses were performed on a LECO CHNS-932 apparatus. MS spectra were carried out on an LC–MS high-resolution time of flight (TOF) Agilent 1200/6530 instrument. All column chromatography was performed on silica gel (60-mesh
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Published 21 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

Graphical Abstract
  • , two 10ADVP pumps, a DGU-14A degasser, a CTO-10AVP column oven and an SPD-10AVP variable wavelength detector. The setup was coupled to a micrOTOF time of flight mass analyzer (Bruker) and controlled by Compass HyStar (Bruker) version 3.2 and microTOFControl (Bruker) version 3.0. Measurement data was
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Published 02 Jul 2020

Aryl-substituted acridanes as hosts for TADF-based OLEDs

  • Naveen Masimukku,
  • Dalius Gudeika,
  • Oleksandr Bezvikonnyi,
  • Ihor Syvorotka,
  • Rasa Keruckiene,
  • Dmytro Volyniuk and
  • Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 989–1000, doi:10.3762/bjoc.16.88

Graphical Abstract
  • interaction. Charge transporting properties To unclose the potential of acridan-based derivatives containing phenyl or naphthyl substituents as hosts for blue TADF OLEDs, charge-transport properties of the vacuum deposited layers of the acridanes were tested by the methods of time-of-flight (TOF) and charge
  • studied compounds were performed by two methods, i.e., time-of-flight (TOF) and charge extraction by linearly increasing voltage (CELIV) in the photo regime [38]. OLEDs were fabricated by vacuum deposition of inorganic and organic layers onto cleaned ITO-coated glass, applying vacuum of 10−6 Torr. The
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Published 13 May 2020

Design and synthesis of diazine-based panobinostat analogues for HDAC8 inhibition

  • Sivaraman Balasubramaniam,
  • Sajith Vijayan,
  • Liam V. Goldman,
  • Xavier A. May,
  • Kyra Dodson,
  • Sweta Adhikari,
  • Fatima Rivas,
  • Davita L. Watkins and
  • Shana V. Stoddard

Beilstein J. Org. Chem. 2020, 16, 628–637, doi:10.3762/bjoc.16.59

Graphical Abstract
  • an ESI–TOF mass spectrometer (Agilent 6220 Time-of-Flight), gas temperature – 350 °C, drying gas (N2) – 8.0 L/min, mobile phase(s): methanol with 0.1% formic acid, flow rate: 0.2 mL/min, sample preparation: The sample was dissolved in 1 drop of chloroform and diluted with 1 mL methanol. Additional
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Published 07 Apr 2020

Direct borylation of terrylene and quaterrylene

  • Haruka Kano,
  • Keiji Uehara,
  • Kyohei Matsuo,
  • Hironobu Hayashi,
  • Hiroko Yamada and
  • Naoki Aratani

Beilstein J. Org. Chem. 2020, 16, 621–627, doi:10.3762/bjoc.16.58

Graphical Abstract
  • -time-of-flight (MALDI–TOF) method on a JEOL SpiralTOF/JMS-S3000 spectrometer. X-ray crystallographic data were recorded at 103 K with a BRUKER-APEXII X-ray diffractometer using Mo Kα radiation equipped with a large area CCD detector. UV–vis absorption spectra were measured with a JASCO UV/Vis/NIR
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Published 06 Apr 2020

Synthesis of 4-(2-fluorophenyl)-7-methoxycoumarin: experimental and computational evidence for intramolecular and intermolecular C–F···H–C bonds

  • Vuyisa Mzozoyana,
  • Fanie R. van Heerden and
  • Craig Grimmer

Beilstein J. Org. Chem. 2020, 16, 190–199, doi:10.3762/bjoc.16.22

Graphical Abstract
  • equipped with a 5 mm BBOZ probe at frequencies of 400 MHz, 100 MHz, and 376 MHz for 1H, 13C, and 19F, respectively. High-resolution mass spectrometry (HRMS) was performed on a Waters LCT Premier time-of-flight mass spectrometer. Synthesis of methyl 2-fluorobenzoylacetate (3): To a stirred mixture of MgCl2
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Published 10 Feb 2020

Acid-catalyzed rearrangements in arenes: interconversions in the quaterphenyl series

  • Sarah L. Skraba-Joiner,
  • Carter J. Holt and
  • Richard P. Johnson

Beilstein J. Org. Chem. 2019, 15, 2655–2663, doi:10.3762/bjoc.15.258

Graphical Abstract
  • through time-of-flight matrix assisted laser desorption ionization (MALDI–TOF–MS) mass spectrometry, using sulfur as a matrix. Suzuki–Miyaura coupling to form m,p’-quaterphenyl (13) [35]: 4-Biphenylboronic acid (0.18 g, 0.91 mmol) and 1 M K2CO3 (1.5 mL) were added to a 10 mL Pyrex microwave tube. 3
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Published 06 Nov 2019

In search of visible-light photoresponsive peptide nucleic acids (PNAs) for reversible control of DNA hybridization

  • Lei Zhang,
  • Greta Linden and
  • Olalla Vázquez

Beilstein J. Org. Chem. 2019, 15, 2500–2508, doi:10.3762/bjoc.15.243

Graphical Abstract
  • AccuTOF GCv 4G (JEOL) Time of Flight (TOF) mass spectrometer (grant: INST 160/622-1 FUGG to Dr. U. Linne). This work was financially supported by German Fulbright Commission and the DFG program SPP1926 ‘Next Generation Optogenetics’. O.V. thanks German Fulbright Commission for the Fulbright-Cottrell Award
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Published 22 Oct 2019

Combining the Ugi-azide multicomponent reaction and rhodium(III)-catalyzed annulation for the synthesis of tetrazole-isoquinolone/pyridone hybrids

  • Gerardo M. Ojeda,
  • Prabhat Ranjan,
  • Pavel Fedoseev,
  • Lisandra Amable,
  • Upendra K. Sharma,
  • Daniel G. Rivera and
  • Erik V. Van der Eycken

Beilstein J. Org. Chem. 2019, 15, 2447–2457, doi:10.3762/bjoc.15.237

Graphical Abstract
  • chromatographic solvents is presented as volume:volume ratios. Isolated compounds were submitted to HRMS using an Agilent 6220A Time of Flight MSD spectrometer equipped with an ESI ionization source. IR spectra were recorded on a Bruker Alpha FTIR spectrometer. Only frequencies (ν, in cm−1) of the most relevant
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Published 16 Oct 2019
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  • ) coupled to a time-of-flight mass spectrometer (TOF–MS) after headspace-solid phase microextraction (HS-SPME). The identification of structurally complex natural compounds, such as sesquiterpenes from fruits and vegetables, is often reported as “tentative”, as authentic standards are not commercially
  • various cyclization reactions [9][10][11][12]. In order to analyze the biosynthetic pathways of sesquiterpene hydrocarbons in grape berries, a method was developed by us using comprehensive two-dimensional gas chromatography (GC×GC) coupled to a time-of-flight mass spectrometer (TOF–MS) after headspace
  • separations were performed by using an Agilent 7890B gas chromatograph (Agilent Technologies, Palo Alto, CA, U.S.A.) equipped with a liquid nitrogen cryogenic modulator (Consumable-Free ZX2 thermal modulator) coupled to a time-of-flight mass spectrometer (Markes International Ltd, Llantrisant, RCT, UK
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Published 14 Aug 2019

Synthesis of a [6]rotaxane with singly threaded γ-cyclodextrins as a single stereoisomer

  • Jason Yin Hei Man and
  • Ho Yu Au-Yeung

Beilstein J. Org. Chem. 2019, 15, 1829–1837, doi:10.3762/bjoc.15.177

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  • HKU Foundation Postgraduate Fellowship. We acknowledge UGC funding administered by The University of Hong Kong for support of the Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry Facilities under support for Interdisciplinary Research in Chemical Science.
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Published 01 Aug 2019

Genomics-inspired discovery of massiliachelin, an agrochelin epimer from Massilia sp. NR 4-1

  • Jan Diettrich,
  • Hirokazu Kage and
  • Markus Nett

Beilstein J. Org. Chem. 2019, 15, 1298–1303, doi:10.3762/bjoc.15.128

Graphical Abstract
  • Nucleoshell RP18 column (150 × 2.0 mm, Macherey-Nagel) using an Agilent 1260 Infinity LC system combined with a Compact quadrupole-time of flight (Q-TOF) mass spectrometer (Bruker Daltonics). The Q-TOF mass spectrometer was interfaced with an electrospray ionization source. NMR spectra were recorded on a
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Published 13 Jun 2019

Bambusuril analogs based on alternating glycoluril and xylylene units

  • Tomáš Lízal and
  • Vladimír Šindelář

Beilstein J. Org. Chem. 2019, 15, 1268–1274, doi:10.3762/bjoc.15.124

Graphical Abstract
  • ESI/APCI as an ion source and a manual pump for sampling. Matrix-assisted laser desorption ionization–time-of-flight mass spectra (MALDI–TOF MS) were measured on a MALDI–TOF MS UltrafleXtreme (Bruker Daltonics) and samples were ionized with the aid of a Nd:YAG laser (355 nm) from α-cyano-4
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Published 11 Jun 2019

Unexpected polymorphism during a catalyzed mechanochemical Knoevenagel condensation

  • Sebastian Haferkamp,
  • Andrea Paul,
  • Adam A. L. Michalchuk and
  • Franziska Emmerling

Beilstein J. Org. Chem. 2019, 15, 1141–1148, doi:10.3762/bjoc.15.110

Graphical Abstract
  • spectra were recorded with electrospray ionization time of flight mass spectrometry. A Q-TOF Ultima ESI-TOF mass spectrometer (Micromass, Germany) running at 4 kV capillary voltage and a cone voltage of 35 V was used. The collision energy was set to 5 eV. The source temperature was 120 °C whereas the
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Published 21 May 2019

New terpenoids from the fermentation broth of the edible mushroom Cyclocybe aegerita

  • Frank Surup,
  • Florian Hennicke,
  • Nadine Sella,
  • Maria Stroot,
  • Steffen Bernecker,
  • Sebastian Pfütze,
  • Marc Stadler and
  • Martin Rühl

Beilstein J. Org. Chem. 2019, 15, 1000–1007, doi:10.3762/bjoc.15.98

Graphical Abstract
  • ). Chemical shifts δ were referenced to the solvents chloroform-d (1H, δ = 7.27 ppm; 13C, δ = 77.0 ppm), acetone-d6 (1H, δ = 2.05 ppm; 13C, δ = 29.92 ppm). ESIMS spectra were acquired on an Amazon ion trap mass spectrometer (Bruker Daltonik); HRESIMS spectra were acquired on a Maxis time-of-flight mass
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Published 30 Apr 2019

Cyclopropene derivatives of aminosugars for metabolic glycoengineering

  • Jessica Hassenrück and
  • Valentin Wittmann

Beilstein J. Org. Chem. 2019, 15, 584–601, doi:10.3762/bjoc.15.54

Graphical Abstract
  • negative mode. The ionization method was electrospray (ESI) and for detection the time of flight (TOF) method was used. Analysis of recorded mass spectra was performed using the software Xcalibur by Thermo Fischer Scientific. 2,5-Dioxopyrrolidin-1-yl 2-methylcyclopropane-1-carboxylate (3): N
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Published 04 Mar 2019

A simple and effective preparation of quercetin pentamethyl ether from quercetin

  • Jin Tatsuzaki,
  • Tomohiko Ohwada,
  • Yuko Otani,
  • Reiko Inagi and
  • Tsutomu Ishikawa

Beilstein J. Org. Chem. 2018, 14, 3112–3121, doi:10.3762/bjoc.14.291

Graphical Abstract
  • the solvent peak for the 1H and 13C NMR spectra. The following abbreviations are used: s = singlet, d = doublet, t = triplet, q = quartet, dd = double doublet. Electron spray ionization time-of-flight mass spectra (ESI–TOF MS) were recorded on a Bruker micrOTOF-05 to give high-resolution mass spectra
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Published 28 Dec 2018

Copolymerization of epoxides with cyclic anhydrides catalyzed by dinuclear cobalt complexes

  • Yo Hiranoi and
  • Koji Nakano

Beilstein J. Org. Chem. 2018, 14, 2779–2788, doi:10.3762/bjoc.14.255

Graphical Abstract
  • initiated by monofunctional pentafluorobenzoate from (R,R,S,S)-1 and [PPN][OCOC6F5] [19]. The formation of the alternating copolymers initiated by monofunctional pentafluorobenzoate and the bifunctional chain-transfer agents was confirmed by matrix-assisted laser desorption/ionization time-of-flight mass
  • atmospheric pressure chemical ionization–time-of-flight (APCI–TOF) method. Size-exclusion-chromatography (SEC) analyses for evaluating molecular weights were carried with two columns (Shodex KF-804L) using chloroform as an eluent at 40 °C at 1 mL/min. The molecular weight was calibrated against standard
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Published 05 Nov 2018

The mechanochemical synthesis of quinazolin-4(3H)-ones by controlling the reactivity of IBX

  • Md Toufique Alam,
  • Saikat Maiti and
  • Prasenjit Mal

Beilstein J. Org. Chem. 2018, 14, 2396–2403, doi:10.3762/bjoc.14.216

Graphical Abstract
  • ), multiplicity (s = singlet, d = doublet, t = triplet, q = quartet, brs = broad singlet, m = multiplet), coupling constant (Hz) and integration. High-resolution mass spectra (HRMS) were recorded on an ESI–TOF (time of flight) mass spectrometer. IR (infrared) spectral data are reported in wave numbers (cm−1
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Published 12 Sep 2018

Novel photochemical reactions of carbocyclic diazodiketones without elimination of nitrogen – a suitable way to N-hydrazonation of C–H-bonds

  • Liudmila L. Rodina,
  • Xenia V. Azarova,
  • Jury J. Medvedev,
  • Dmitrij V. Semenok and
  • Valerij A. Nikolaev

Beilstein J. Org. Chem. 2018, 14, 2250–2258, doi:10.3762/bjoc.14.200

Graphical Abstract
  • using Merck silica gel 60, 230–400 mesh. 1H and 13C NMR spectra were recorded using a Bruker-400 Avance NMR spectrometer. All HRMS spectra were recorded on a «MaXis» (Bruker Daltonik GmbH), the HPLC system (UHPLC) with the combined high-resolution quadrupole-time-of-flight mass spectrometer with
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Published 28 Aug 2018

Efficient catenane synthesis by cucurbit[6]uril-mediated azide–alkyne cycloaddition

  • Antony Wing Hung Ng,
  • Chi-Chung Yee,
  • Kai Wang and
  • Ho Yu Au-Yeung

Beilstein J. Org. Chem. 2018, 14, 1846–1853, doi:10.3762/bjoc.14.158

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  • for support of the Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry Facilities under support for Interdisciplinary Research in Chemical Science.
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Published 20 Jul 2018

Synthesis and photophysical studies of a multivalent photoreactive RuII-calix[4]arene complex bearing RGD-containing cyclopentapeptides

  • Sofia Kajouj,
  • Lionel Marcelis,
  • Alice Mattiuzzi,
  • Adrien Grassin,
  • Damien Dufour,
  • Pierre Van Antwerpen,
  • Didier Boturyn,
  • Eric Defrancq,
  • Mathieu Surin,
  • Julien De Winter,
  • Pascal Gerbaux,
  • Ivan Jabin and
  • Cécile Moucheron

Beilstein J. Org. Chem. 2018, 14, 1758–1768, doi:10.3762/bjoc.14.150

Graphical Abstract
  • ; source temperature, 150 °C and desolvation temperature, 200 °C. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) mass spectra were recorded using a Waters QToF Premier mass spectrometer equipped with a Nd-YAG laser of 355 nm with a maximum pulse energy of 65 μJ delivered to the
  • sample at 50 Hz repeating rate. Time-of-flight mass analyses were performed in the reflection mode at a resolution of about 10 000. The matrix, trans-2-(3-(4-tert-butylphenyl)-2-methyl-2-propenylidene)malononitrile, was prepared as a 40 mg/mL solution in chloroform. The matrix solution (1 μL) was applied
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Published 16 Jul 2018

The phenyl vinyl ether–methanol complex: a model system for quantum chemistry benchmarking

  • Dominic Bernhard,
  • Fabian Dietrich,
  • Mariyam Fatima,
  • Cristóbal Pérez,
  • Hannes C. Gottschalk,
  • Axel Wuttke,
  • Ricardo A. Mata,
  • Martin A. Suhm,
  • Melanie Schnell and
  • Markus Gerhards

Beilstein J. Org. Chem. 2018, 14, 1642–1654, doi:10.3762/bjoc.14.140

Graphical Abstract
  • setup for the IR/UV experiments is described in detail elsewhere [29][50], thus only a brief description is given here. All experiments were carried out in a molecular beam apparatus consisting of a differentially pumped linear time-of-flight (TOF) mass spectrometer with a pulsed valve (Series 9 and
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Published 02 Jul 2018

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
  • −1 indicates complexation [51]. The sample Polymer-SF-3 was investigated by matrix-assisted laser desorption/ionization with a time-of-flight mass spectrometer (MALDI–TOF) revealing a weight-averaged molar mass (Mw) of 2015.6 g mol−1, which is equivalent to 6 monomeric units. Synthesis of the
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Published 06 Jul 2017
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