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Search for "mass spectrometry" in Full Text gives 649 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Naphthalene diimide–amino acid conjugates as novel fluorimetric and CD probes for differentiation between ds-DNA and ds-RNA

  • Annike Weißenstein,
  • Myroslav O. Vysotsky,
  • Ivo Piantanida and
  • Frank Würthner

Beilstein J. Org. Chem. 2020, 16, 2032–2045, doi:10.3762/bjoc.16.170

Graphical Abstract
  • Avance 400 spectrometer. The chemical shifts are reported in ppm and refer to the residual proton signal of the solvent as internal standard. Signal multiplicities are denoted as s (singlet), d (doublet), t (triplet), and m (multiplet). High-resolution ESI-TOF mass spectrometry was carried out on a
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Published 19 Aug 2020

pH- and concentration-dependent supramolecular self-assembly of a naturally occurring octapeptide

  • Goutam Ghosh and
  • Gustavo Fernández

Beilstein J. Org. Chem. 2020, 16, 2017–2025, doi:10.3762/bjoc.16.168

Graphical Abstract
  • of the peptide (Figure S2, Supporting Information File 1). The identity of the peptide was confirmed by MALDI–TOF mass spectrometry (Figure S3, Supporting Information File 1). The yield of the purified PEP-1 was 42%. Self-assembly and secondary-structure formation CD, FTIR spectroscopy, and ThT
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Published 17 Aug 2020

Regiodivergent synthesis of functionalized pyrimidines and imidazoles through phenacyl azides in deep eutectic solvents

  • Paola Vitale,
  • Luciana Cicco,
  • Ilaria Cellamare,
  • Filippo M. Perna,
  • Antonio Salomone and
  • Vito Capriati

Beilstein J. Org. Chem. 2020, 16, 1915–1923, doi:10.3762/bjoc.16.158

Graphical Abstract
  • heating to 473 K until blue spots appeared. Column chromatography was conducted by using silica gel 60 with a particle size distribution of 40–63 μm and 230–400 ASTM, using hexane/EtOAc mixtures as the eluent. High-resolution mass spectrometry (HRMS) analyses were performed using a Bruker microTOF QII
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Published 05 Aug 2020

Three new O-isocrotonyl-3-hydroxybutyric acid congeners produced by a sea anemone-derived marine bacterium of the genus Vibrio

  • Dandan Li,
  • Enjuro Harunari,
  • Tao Zhou,
  • Naoya Oku and
  • Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1869–1874, doi:10.3762/bjoc.16.154

Graphical Abstract
  • -hydroxybutyric acid (4). The structures of 1–3 were established by NMR spectroscopy and mass spectrometry, coupled with anisotropy-based chiral analysis, revealing the same R-configuration for all congeners 1–4. The compounds 1–4 were weakly growth-inhibitory against a marine fish ulcer pathogenic bacterium
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Published 29 Jul 2020

Nonenzymatic synthesis of anomerically pure, mannosyl-based molecular probes for scramblase identification studies

  • Giovanni Picca,
  • Markus Probst,
  • Simon M. Langenegger,
  • Oleg Khorev,
  • Peter Bütikofer,
  • Anant K. Menon and
  • Robert Häner

Beilstein J. Org. Chem. 2020, 16, 1732–1739, doi:10.3762/bjoc.16.145

Graphical Abstract
  • membrane proteins [11][12]. The captured proteins would be subsequently identified by mass spectrometry, and their function in MPD scrambling validated by biochemical and genetic approaches. A suitable molecular probe and mimic of MPD (Figure 1) can be subdivided into three essential components: a β-ᴅ
  • candidates (identification by mass spectrometry), and the other probe, MPC-2, consists of a fluorescent label to test candidates for scramblase activity in reconstitution-based assays. The molecular probes were prepared via phosphoramidite chemistry, which allowed the incorporation of the carbohydrate
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Published 20 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
  • 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
  • combination of cyclic tripeptide dimer. Each peptide dimer has two peaks because of the two constitutional isomers. Note that intensities between different compounds are not directly comparable in mass spectrometry. Upon addition of certain templates, notable changes were found in the chromatograms of the CFC
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Published 02 Jul 2020

NHC-catalyzed enantioselective synthesis of β-trifluoromethyl-β-hydroxyamides

  • Alyn T. Davies,
  • Mark D. Greenhalgh,
  • Alexandra M. Z. Slawin and
  • Andrew D. Smith

Beilstein J. Org. Chem. 2020, 16, 1572–1578, doi:10.3762/bjoc.16.129

Graphical Abstract
  • : Experimental procedures, product characterization data (mp, NMR, IR, HRMS, [α]D, HPLC), and spectra (1H, 13C, and 19F NMR, HPLC). Supporting Information File 336: Crystallographic details for 12. Acknowledgements We thank the EPSRC UK National Mass Spectrometry Facility at Swansea University. Funding We thank
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Published 30 Jun 2020

Five-component, one-pot synthesis of an electroactive rotaxane comprising a bisferrocene macrocycle

  • Natalie Lagesse,
  • Luca Pisciottani,
  • Maxime Douarre,
  • Pascale Godard,
  • Brice Kauffmann,
  • Vicente Martí-Centelles and
  • Nathan D. McClenaghan

Beilstein J. Org. Chem. 2020, 16, 1564–1571, doi:10.3762/bjoc.16.128

Graphical Abstract
  • million (ppm) and coupling constants J are given in hertz (Hz). Multiplicity for each signal is indicated as follows: s = singlet, br s = broad singlet, d = doublet, t = triplet, and m = multiplet. Mass spectrometry: Field desorption spectra (FD) were recorded on an AccuTOF (JEOL) mass spectrometer using
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Published 30 Jun 2020

Heterogeneous photocatalysis in flow chemical reactors

  • Christopher G. Thomson,
  • Ai-Lan Lee and
  • Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

Graphical Abstract
  • monitored with in-line and on-line spectroscopies, such as UV–vis, FTIR, mass spectrometry, and NMR [63][64][65][66][67][68]. These systems can be automated to ensure consistency and to remove the need for laborious manual sampling. In-line and on-line monitoring is well aligned with automated synthesis and
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Published 26 Jun 2020

The McKenna reaction – avoiding side reactions in phosphonate deprotection

  • Katarzyna Justyna,
  • Joanna Małolepsza,
  • Damian Kusy,
  • Waldemar Maniukiewicz and
  • Katarzyna M. Błażewska

Beilstein J. Org. Chem. 2020, 16, 1436–1446, doi:10.3762/bjoc.16.119

Graphical Abstract
  • ). Further, we confirmed the identity of brominated product 22 by mass spectrometry. Under these conditions compound 13 underwent an almost complete exchange of chlorine for bromine in the presence of BTMS in MeCN at 35 °C within 3 h (Table 3, entry 1). Changing the solvent to the non-polar aprotic solvent
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Published 23 Jun 2020

Activated carbon as catalyst support: precursors, preparation, modification and characterization

  • Melanie Iwanow,
  • Tobias Gärtner,
  • Volker Sieber and
  • Burkhard König

Beilstein J. Org. Chem. 2020, 16, 1188–1202, doi:10.3762/bjoc.16.104

Graphical Abstract
  • gases were determined by mass spectrometry. In general, each type of surface group decomposes to a defined product such as CO2 from carboxylic acid or lactones and CO from carbonyl, hydroxide, phenol, ether or quinone groups and thus, information on the amounts of oxygen-containing surface groups are
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Published 02 Jun 2020

Development of fluorinated benzils and bisbenzils as room-temperature phosphorescent molecules

  • Shigeyuki Yamada,
  • Takuya Higashida,
  • Yizhou Wang,
  • Masato Morita,
  • Takuya Hosokai,
  • Kaveendra Maduwantha,
  • Kaveenga Rasika Koswattage and
  • Tsutomu Konno

Beilstein J. Org. Chem. 2020, 16, 1154–1162, doi:10.3762/bjoc.16.102

Graphical Abstract
  • resonance (NMR) spectroscopy, infrared spectroscopy, and high-resolution mass spectrometry) successfully identified the more polar product as the half-oxidized benzil 2a and the less polar one as the fully oxidized bisbenzil 3a. Fluorinated bistolane 1b, bearing a hexyloxy chain, also underwent PdCl2
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Published 29 May 2020

Synthesis and properties of quinazoline-based versatile exciplex-forming compounds

  • Rasa Keruckiene,
  • Simona Vekteryte,
  • Ervinas Urbonas,
  • Matas Guzauskas,
  • Eigirdas Skuodis,
  • Dmytro Volyniuk and
  • Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 1142–1153, doi:10.3762/bjoc.16.101

Graphical Abstract
  • mass spectrometry. All compounds 1–3 were obtained as crystalline substances. The thermal characteristics were determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). During the first DSC heating scan (Figure 1a–c), melting signals of compounds 1–3 were detected in
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Published 28 May 2020

Palladium-catalyzed regio- and stereoselective synthesis of aryl and 3-indolyl-substituted 4-methylene-3,4-dihydroisoquinolin-1(2H)-ones

  • Valeria Nori,
  • Antonio Arcadi,
  • Armando Carlone,
  • Fabio Marinelli and
  • Marco Chiarini

Beilstein J. Org. Chem. 2020, 16, 1084–1091, doi:10.3762/bjoc.16.95

Graphical Abstract
  • ppm) or tetramethylsilane (δ = 0 ppm). Mass spectrometry was performed using a MALDI–TOF spectrometer AB SCIEX TOF/TOF 5800 system using 3-hydroxycoumarin or α-cyano-4-hydroxycinnamic acid as a matrix in combination with KI for the ionization. Unless otherwise stated, all starting materials, catalysts
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Published 20 May 2020

Synthesis of novel multifunctional carbazole-based molecules and their thermal, electrochemical and optical properties

  • Nuray Altinolcek,
  • Ahmet Battal,
  • Mustafa Tavasli,
  • William J. Peveler,
  • Holly A. Yu and
  • Peter J. Skabara

Beilstein J. Org. Chem. 2020, 16, 1066–1074, doi:10.3762/bjoc.16.93

Graphical Abstract
  • spectroscopy, mass spectrometry, FTIR, thermogravimetric analysis, differential scanning calorimetry, cyclic voltammetry, and absorption and emission spectroscopy. Compounds 7a and 7b, both of which were amorphous solids, were stable up to 291 °C and 307 °C, respectively. Compounds 7a and 7b show three
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Published 19 May 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
  • presence of a palladium catalyst, with yields ranging from 27 to 50%. The chemical structures of 3–6 were confirmed by 1H and 13C NMR spectroscopy, elemental analysis and mass spectrometry. Transparent thin films of these compounds could be prepared by vacuum evaporation or by spin coating from solutions
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Published 13 May 2020

Accelerating fragment-based library generation by coupling high-performance photoreactors with benchtop analysis

  • Quentin Lefebvre,
  • Christophe Salomé and
  • Thomas C. Fessard

Beilstein J. Org. Chem. 2020, 16, 982–988, doi:10.3762/bjoc.16.87

Graphical Abstract
  • coupled to benchtop analysis tools, namely thin-layer chromatography–mass spectrometry (TLC–MS, purchased from https://www.advion.com/rsc-product-note/direct-mass-analysis-of-tlc-plates/) and low-field nuclear magnetic resonance (NMR, purchased from https://www.nanalysis.com/) analysis (Scheme 1). To
  • preliminary quality control (QC) could be performed using a benchtop 60 MHz NMR machine (Figure 3). Structural information was obtained to corroborate mass spectrometry data, an important information when dealing with strained bicycles or spirocycles, which could be prone to skeletal rearrangement. If
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Published 12 May 2020

Cation-induced ring-opening and oxidation reaction of photoreluctant spirooxazine–quinolizinium conjugates

  • Phil M. Pithan,
  • Sören Steup and
  • Heiko Ihmels

Beilstein J. Org. Chem. 2020, 16, 904–916, doi:10.3762/bjoc.16.82

Graphical Abstract
  • compounds 3a and 3b were confirmed by NMR spectroscopy (1H, 13C, COSY, HSQC, HMBC), mass spectrometry (ESIMS), and elemental analysis. Photophysical and photochemical properties The absorption spectra of 3a and 3b exhibit the characteristic long-wavelength absorption bands of the styryl-substituted
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Published 05 May 2020

Bipyrrole boomerangs via Pd-mediated tandem cyclization–oxygenation. Controlling reaction selectivity and electronic properties

  • Liliia Moshniaha,
  • Marika Żyła-Karwowska,
  • Joanna Cybińska,
  • Piotr J. Chmielewski,
  • Ludovic Favereau and
  • Marcin Stępień

Beilstein J. Org. Chem. 2020, 16, 895–903, doi:10.3762/bjoc.16.81

Graphical Abstract
  • below 1 equiv (Table 1, entries 16 and 22). Structure The identity of the α-oxygenated products, cRnO, was determined on the basis of high-resolution mass spectrometry and 1H and 13C NMR data. In particular, the 1H NMR spectrum of cNMI2O revealed the absence of the pyrrolic α-H resonances, whereas the
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Published 04 May 2020

Synthesis of new asparagine-based glycopeptides for future scanning tunneling microscopy investigations

  • Laura Sršan and
  • Thomas Ziegler

Beilstein J. Org. Chem. 2020, 16, 888–894, doi:10.3762/bjoc.16.80

Graphical Abstract
  • comparison with naturally occurring amino acids [14]. Thus, there is still a great effort in finding new potential drugs derived from glycopeptides [4][15]. By using preparative mass spectrometry (pMS) combined with STM on submolecular-resolution peptides and carbohydrates can be investigated regarding their
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Published 30 Apr 2020

Aldehydes as powerful initiators for photochemical transformations

  • Maria A. Theodoropoulou,
  • Nikolaos F. Nikitas and
  • Christoforos G. Kokotos

Beilstein J. Org. Chem. 2020, 16, 833–857, doi:10.3762/bjoc.16.76

Graphical Abstract
  • three possible dissociation pathways that can be followed (Scheme 5). Moreover, Reilly and co-workers observed the decomposition of benzaldehyde (8) into benzene (21) and carbon monoxide (22) (reaction (3) in Scheme 5) after the irradiation at 258.9 nm via laser ionization mass spectrometry and
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Published 23 Apr 2020

Towards triptycene functionalization and triptycene-linked porphyrin arrays

  • Gemma M. Locke,
  • Keith J. Flanagan and
  • Mathias O. Senge

Beilstein J. Org. Chem. 2020, 16, 763–777, doi:10.3762/bjoc.16.70

Graphical Abstract
  • , copies of NMR and UV–vis spectra, mass spectrometry analyses and X-ray crystallographic details. Supporting Information File 173: Crystal structure determination of compound 5. Supporting Information File 174: Crystal structure determination of compound 16. Funding This work was supported by grants from
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Published 17 Apr 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
  • C18 column chromatography. All the final compounds were thoroughly characterized by NMR and mass spectrometry (see Supporting Information File 1). Having successfully synthesized the targets TOI1 to TOI4, our next aim was to evaluate them biologically. Inhibition assay The biochemical evaluation of
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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
  • -dioxane (5 mL) under Ar at 105 °C for 30 h gave a deep orange solution (Scheme 1). Matrix assisted laser desorption/ionization (MALDI) mass spectrometry of the reaction mixture detected a single parent ion peak at m/z = 880.4687 (calcd for C54H60B4O8 = 880.4660 [M]+), making us expect its selective tetra
  • ]. However, the crude product was not completely purified by Soxhlet extraction and by crystallization in our hands. The borylation reaction of hardly soluble crude quaterrylene gave a deep green suspension. MALDI mass spectrometry of the reaction mixture detected an ion peak at m/z = 1004.5018 (calcd for
  • 2,5,10,13-tetramesitylterrylene (TM4) in 58% yield. TM4 was successfully isolated through a silica gel pad and by reprecipitation. The structure of TM4 was characterized by mass spectrometry and 1H and 13C NMR spectroscopy. High-resolution MALDI mass spectrometry detected the parent ion peak at m/z
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Published 06 Apr 2020

Regioselectively α- and β-alkynylated BODIPY dyes via gold(I)-catalyzed direct C–H functionalization and their photophysical properties

  • Takahide Shimada,
  • Shigeki Mori,
  • Masatoshi Ishida and
  • Hiroyuki Furuta

Beilstein J. Org. Chem. 2020, 16, 587–595, doi:10.3762/bjoc.16.53

Graphical Abstract
  • used as the substrate for the gold(I) catalyzed reaction (Scheme 1). Mixing five mol % of gold(I) chloride and two equivalents of TIPS-EBX with a diethyl ether solution of 2 under ambient conditions yielded a mixture of ethynyl-substituted dipyrromethanes as judged by mass spectrometry. The product
  • of TIPS-ethynyl-substituted BODIPY derivatives 3–6 were characterized by 1H and 19F NMR spectroscopy, high-resolution mass spectrometry, and X-ray crystallographic analysis. The solid-state structures of the diethynyl-substituted BODIPYs were unambiguously elucidated by X-ray diffraction analysis (3a
  • comparative NMR analysis and mass spectrometry (see Supporting Information File 1). Optical properties The α- and β-ethynyl-substituted BODIPYs exhibit large bathochromic shifts in the absorption and fluorescence spectra relative to the unsubstituted 1a with extended π-conjugation (Figure 4 and Figure 5). The
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Published 01 Apr 2020
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