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Search for "resolution" in Full Text gives 799 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Characterization of a new fusicoccane-type diterpene synthase and an associated P450 enzyme

  • Jia-Hua Huang,
  • Jian-Ming Lv,
  • Liang-Yan Xiao,
  • Qian Xu,
  • Fu-Long Lin,
  • Gao-Qian Wang,
  • Guo-Dong Chen,
  • Sheng-Ying Qin,
  • Dan Hu and
  • Hao Gao

Beilstein J. Org. Chem. 2022, 18, 1396–1402, doi:10.3762/bjoc.18.144

Graphical Abstract
  • , production of 1 was increased by five-fold (Figure 3A, line iii). Finally, we isolated 1 and 2 through large-scale fermentation. On the basis of the quasi-molecular ion at m/z 273.2599 [M + H]+ (calcd. for C20H33, 273.2582) (Supporting Information File 1, Figure S2) detected by high-resolution electrospray
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Published 05 Oct 2022

Preparation of an advanced intermediate for the synthesis of leustroducsins and phoslactomycins by heterocycloaddition

  • Anaïs Rousseau,
  • Guillaume Vincent and
  • Cyrille Kouklovsky

Beilstein J. Org. Chem. 2022, 18, 1385–1395, doi:10.3762/bjoc.18.143

Graphical Abstract
  • solvent using residual chloroform (7.26 ppm) as an internal reference. 13C NMR spectra were measured at 62.5, 75 or 90 MHz using residual chloroform (77.1 ppm) as an internal reference. High-resolution mass spectrometry (HRMS) analyses were conducted with electro spray ionization (ESI). 6
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Published 04 Oct 2022

Computational model predicts protein binding sites of a luminescent ligand equipped with guanidiniocarbonyl-pyrrole groups

  • Neda Rafieiolhosseini,
  • Matthias Killa,
  • Thorben Neumann,
  • Niklas Tötsch,
  • Jean-Noël Grad,
  • Alexander Höing,
  • Thies Dirksmeyer,
  • Jochen Niemeyer,
  • Christian Ottmann,
  • Shirley K. Knauer,
  • Michael Giese,
  • Jens Voskuhl and
  • Daniel Hoffmann

Beilstein J. Org. Chem. 2022, 18, 1322–1331, doi:10.3762/bjoc.18.137

Graphical Abstract
  • distribution; this approach captures ion-size effects and yields energy grids that are directly comparable to molecular dynamics simulation data. Accordingly, the 14-3-3ζ environment was scanned with the GCP and lysine ligands separately in Epitopsy using 150 rotations and a grid resolution of 0.4 Å to
  • generate a pre-calculated Hamiltonian for a grid-based description of the electrostatic and van der Waals interactions. We have also tried a grid resolution of 0.8 Å which would have allowed more efficient calculations. However, the 0.8 Å resolution was not fine enough to accurately capture essential
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Published 23 Sep 2022

Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells

  • Merve Karaman,
  • Abhishek Kumar Gupta,
  • Subeesh Madayanad Suresh,
  • Tomas Matulaitis,
  • Lorenzo Mardegan,
  • Daniel Tordera,
  • Henk J. Bolink,
  • Sen Wu,
  • Stuart Warriner,
  • Ifor D. Samuel and
  • Eli Zysman-Colman

Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136

Graphical Abstract
  • synthetic strategy, which itself was synthesized from Br-DiKTa [28] following a Buchwald–Hartwig coupling. Details of the synthesis are found in Supporting Information File 1. The identity and purity of the molecules were verified using a combination of 1H and 13C NMR spectroscopy, high resolution mass
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Published 22 Sep 2022

Cytochrome P450 monooxygenase-mediated tailoring of triterpenoids and steroids in plants

  • Karan Malhotra and
  • Jakob Franke

Beilstein J. Org. Chem. 2022, 18, 1289–1310, doi:10.3762/bjoc.18.135

Graphical Abstract
  • ete3 package. Annotations in Figure 2 were created with BioRender.com. This content is not subject to CC BY 4.0. A high resolution version with tip labels is available as Supporting Information File 1. CYPs modifying steroid (A), cucurbitacin steroid (B) and tetracyclic triterpene (C) backbones
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Published 21 Sep 2022

Enantioselective total synthesis of putative dihydrorosefuran, a monoterpene with an unique 2,5-dihydrofuran structure

  • Irene Torres-García,
  • Josefa L. López-Martínez,
  • Rocío López-Domene,
  • Manuel Muñoz-Dorado,
  • Ignacio Rodríguez-García and
  • Miriam Álvarez-Corral

Beilstein J. Org. Chem. 2022, 18, 1264–1269, doi:10.3762/bjoc.18.132

Graphical Abstract
  • stereoselective kinetic resolution of allenol 3 via lipase AK-catalyzed acetylation [15]. In this way, unaltered, (−)-hydroxyallene 3 could be separated from (+)-acetyl derivative 9 through standard column chromatography (Scheme 3). Enantiomeric excesses of (−)-3 and (+)-9 were determined by chiral HPLC analyses
  • ) AgNO3, Me2CO, 75%. Racemic resolution of allenol 3 and synthesis of derivatives. a) Lipase AK, vinyl acetate, t-BuOMe, 30 °C, ((−)-(S)-3: 46%, 90% ee, (+)-(R)-9: 39%, 95% ee); b) N,N’-dicyclohexylcarbodiimide (DCC), dimethylaminopyridine (DMAP), (S) or (R)-(−)-α-methoxy-α-(trifluoromethyl)phenylacetic
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Published 19 Sep 2022

Thermally activated delayed fluorescence (TADF) emitters: sensing and boosting spin-flipping by aggregation

  • Ashish Kumar Mazumdar,
  • Gyana Prakash Nanda,
  • Nisha Yadav,
  • Upasana Deori,
  • Upasha Acharyya,
  • Bahadur Sk and
  • Pachaiyappan Rajamalli

Beilstein J. Org. Chem. 2022, 18, 1177–1187, doi:10.3762/bjoc.18.122

Graphical Abstract
  • Supporting Information File 1. Both compounds were further purified by temperature-gradient vacuum sublimation and characterized by 1H and 13C NMR spectroscopy (Figures S9–S12, Supporting Information File 1) as well as high-resolution mass spectrometry. Photophysical studies and DFT calculations The UV–vis
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Published 08 Sep 2022

Experimental and theoretical studies on the synthesis of 1,4,5-trisubstituted pyrrolidine-2,3-diones

  • Nguyen Tran Nguyen,
  • Vo Viet Dai,
  • Nguyen Ngoc Tri,
  • Luc Van Meervelt,
  • Nguyen Tien Trung and
  • Wim Dehaen

Beilstein J. Org. Chem. 2022, 18, 1140–1153, doi:10.3762/bjoc.18.118

Graphical Abstract
  • spectrometer (Synapt G2 HDMS, Waters, Milford, MA). Samples were infused at 3 μL/min and spectra were obtained in positive (or negative) ionization mode with a resolution of 15000 (FWHM) using leucine enkephalin as lock mass. Besides, exact mass measurements were also recorded on a SCIEX X500 QTOF with
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Published 31 Aug 2022

Synthesis of N-phenyl- and N-thiazolyl-1H-indazoles by copper-catalyzed intramolecular N-arylation of ortho-chlorinated arylhydrazones

  • Yara Cristina Marchioro Barbosa,
  • Guilherme Caneppele Paveglio,
  • Claudio Martin Pereira de Pereira,
  • Sidnei Moura,
  • Cristiane Storck Schwalm,
  • Gleison Antonio Casagrande and
  • Lucas Pizzuti

Beilstein J. Org. Chem. 2022, 18, 1079–1087, doi:10.3762/bjoc.18.110

Graphical Abstract
  • signal at 8.21 ppm and the hydrazone triplet at 6.89 ppm, respectively, vs the integral value of the calibration compound singlet at 6.46 ppm (see Supporting Information File 1). HRMS spectra were acquired on a hybrid high-resolution and high-accuracy microTof (Q-TOF, Bruker Scientific) spectrometer with
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Published 23 Aug 2022

Synthesis, optical and electrochemical properties of (D–π)2-type and (D–π)2Ph-type fluorescent dyes

  • Kosuke Takemura,
  • Kazuki Ohira,
  • Taiki Higashino,
  • Keiichi Imato and
  • Yousuke Ooyama

Beilstein J. Org. Chem. 2022, 18, 1047–1054, doi:10.3762/bjoc.18.106

Graphical Abstract
  • OTT-2 to OTK-2. Experimental General methods Melting points were measured with an AS ONE ATM-02 apparatus. IR spectra were recorded on a SHIMADZU IRTracer-100 spectrometer by ATR method. 1H NMR and 13C NMR spectra were recorded on a Varian-500 FT NMR spectrometer. High-resolution mass spectral data by
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Published 18 Aug 2022

On Reuben G. Jones synthesis of 2-hydroxypyrazines

  • Pierre Legrand and
  • Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 935–943, doi:10.3762/bjoc.18.93

Graphical Abstract
  • description of the experimental set up is provided in Supporting Information File 1. The low-resolution mass spectra were obtained on an Agilent 1200 series LC/MSD system using an Agilent Jet-Stream atmospheric electrospray ionization system and the high-resolution mass spectra (HRMS) were obtained using a
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Published 29 Jul 2022

Cathodic generation of reactive (phenylthio)difluoromethyl species and its reactions: mechanistic aspects and synthetic applications

  • Sadanobu Iwase,
  • Shinsuke Inagi and
  • Toshio Fuchigami

Beilstein J. Org. Chem. 2022, 18, 872–880, doi:10.3762/bjoc.18.88

Graphical Abstract
  • difluorocarbene adduct 5 was detected by high resolution mass spectrometry in addition to products 2, 3, and 4. As already mentioned, SmI2 is a well-known one-electron reducing reagent, and has been used to generate PhSCF2 radicals and perfluoroalkyl radicals from PhSCF2Br and perfluoroalkyl halides, respectively
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Published 20 Jul 2022

First series of N-alkylamino peptoid homooligomers: solution phase synthesis and conformational investigation

  • Maxime Pypec,
  • Laurent Jouffret,
  • Claude Taillefumier and
  • Olivier Roy

Beilstein J. Org. Chem. 2022, 18, 845–854, doi:10.3762/bjoc.18.85

Graphical Abstract
  • ) after coupling and TFA-mediated Boc removal. Structural characterization of N-methylamino peptoid oligomers X-ray diffraction analysis of peptoid dimer 2 Peptoid dimer 2 was crystallized by slow evaporation from chloroform, and its high resolution structure was determined by X-ray crystallography. The
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Published 14 Jul 2022

Synthesis and HDAC inhibitory activity of pyrimidine-based hydroxamic acids

  • Virginija Jakubkiene,
  • Gabrielius Ernis Valiulis,
  • Markus Schweipert,
  • Asta Zubriene,
  • Daumantas Matulis,
  • Franz-Josef Meyer-Almes and
  • Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 837–844, doi:10.3762/bjoc.18.84

Graphical Abstract
  • chromatography was performed using silica gel 60 (0.040–0.063 mm) (Merck). NMR spectra were recorded on a Bruker Ascend 400 spectrometer (400 MHz and 100 MHz for 1H and 13C, respectively). 1H NMR and 13C NMR were referenced to residual solvent peaks. High-resolution mass spectrometry (HRMS) analyses were carried
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Published 13 Jul 2022

Identification of the new prenyltransferase Ubi-297 from marine bacteria and elucidation of its substrate specificity

  • Jamshid Amiri Moghaddam,
  • Huijuan Guo,
  • Karsten Willing,
  • Thomas Wichard and
  • Christine Beemelmanns

Beilstein J. Org. Chem. 2022, 18, 722–731, doi:10.3762/bjoc.18.72

Graphical Abstract
  • presence of Mg2+ as co-factor. Product formation was monitored after 2 h using high-resolution tandem mass spectrometry (HRMS/MS). Membrane proteins obtained from E. coli BL21 cultures harboring the empty expression pET28 plasmid were used as negative control (Figure S3 in Supporting Information File 1
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Published 22 Jun 2022

Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies

  • Conrad Kuhwald,
  • Sibel Türkhan and
  • Andreas Kirschning

Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70

Graphical Abstract
  • in that the actual temperature of the glass/metal surface could be determined locally using a high-resolution IR camera. It was found to be 950 °C and not 185 °C of the reaction mixture itself. These studies are noteworthy because it can be assumed that the temperatures determined by Organ locally on
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Published 20 Jun 2022

New synthesis of a late-stage tetracyclic key intermediate of lumateperone

  • Mátyás Milen,
  • Bálint Nyulasi,
  • Tamás Nagy,
  • Gyula Simig and
  • Balázs Volk

Beilstein J. Org. Chem. 2022, 18, 653–659, doi:10.3762/bjoc.18.66

Graphical Abstract
  • with triethylsilane in TFA to cis-racemate 15. The key step of the syntheses is the resolution of this intermediate with (R)-mandelic acid. The enantiomerically pure (R)-mandelate salt 16 thus obtained was reacted with ethyl chloroformate to give 17. It was then transformed to tetracyclic derivative 8
  • give the racemic form of lumateperone [(±)-1]. It has to be mentioned that the resolution of none of the racemic intermediates of this synthetic route was disclosed [11][12]. Results and Discussion From the technological point of view, the obvious common disadvantage of the methods described above for
  • ] for the resolution of compound (±)-10, a direct intermediate of lumateperone, easily available from (±)-9a, we aimed to elaborate a new, practical synthesis of the latter. First, we envisaged a new synthetic route to the racemic key intermediate (±)-9a, significantly shorter than those described
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Published 10 Jun 2022

Shift of the reaction equilibrium at high pressure in the continuous synthesis of neuraminic acid

  • Jannis A. Reich,
  • Miriam Aßmann,
  • Kristin Hölting,
  • Paul Bubenheim,
  • Jürgen Kuballa and
  • Andreas Liese

Beilstein J. Org. Chem. 2022, 18, 567–579, doi:10.3762/bjoc.18.59

Graphical Abstract
  • were added as substrates to produce Neu5Ac. The resulting progress curve is shown in Figure 14. In order to measure changes in concentration with a high resolution, a high working volume was selected and the enzyme concentrations were reduced, leading to a slower conversion. Pressure was then varied
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Published 20 May 2022

Terpenoids from Glechoma hederacea var. longituba and their biological activities

  • Dong Hyun Kim,
  • Song Lim Ham,
  • Zahra Khan,
  • Sun Yeou Kim,
  • Sang Un Choi,
  • Chung Sub Kim and
  • Kang Ro Lee

Beilstein J. Org. Chem. 2022, 18, 555–566, doi:10.3762/bjoc.18.58

Graphical Abstract
  • a Jasco P-2000 polarimeter using methanol as solvent. High-resolution ESI mass spectrometer data were recorded on a Waters SYNAPT G2 mass spectrometer. ECD spectra were garnered with a JASCO J-1500 CD spectrometer (JASCO, Easton, MD, USA). The NMR spectra were recorded on a Bruker AVANCE III 700 NMR
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Published 17 May 2022

Substituent effect on TADF properties of 2-modified 4,6-bis(3,6-di-tert-butyl-9-carbazolyl)-5-methylpyrimidines

  • Irina Fiodorova,
  • Tomas Serevičius,
  • Rokas Skaisgiris,
  • Saulius Juršėnas and
  • Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 497–507, doi:10.3762/bjoc.18.52

Graphical Abstract
  • and 100 MHz for 1H and 13C, respectively). 1H NMR and 13C NMR spectra were referenced to residual solvent peaks. High-resolution mass spectrometry (HRMS) analyses were carried out on a Dual-ESI Q-TOF 6520 (Agilent Technologies) mass spectrometer. Photophysical properties were analyzed in 10−5 M
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Published 05 May 2022

Synthesis of 3,4,5-trisubstituted isoxazoles in water via a [3 + 2]-cycloaddition of nitrile oxides and 1,3-diketones, β-ketoesters, or β-ketoamides

  • Md Imran Hossain,
  • Md Imdadul H. Khan,
  • Seong Jong Kim and
  • Hoang V. Le

Beilstein J. Org. Chem. 2022, 18, 446–458, doi:10.3762/bjoc.18.47

Graphical Abstract
  • using an OptiMelt automated melting point system. Exact high-resolution mass determinations were analyzed on a JEOL AccuToF 4G LCplus atmospheric pressure ionization time-of-flight mass spectrometer (Jeol, Tokyo, Japan) fitted with direct analysis in real-time (DART) ion source (IonSense DART controller
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Published 22 Apr 2022

The asymmetric Henry reaction as synthetic tool for the preparation of the drugs linezolid and rivaroxaban

  • Martin Vrbický,
  • Karel Macek,
  • Jaroslav Pochobradský,
  • Jan Svoboda,
  • Miloš Sedlák and
  • Pavel Drabina

Beilstein J. Org. Chem. 2022, 18, 438–445, doi:10.3762/bjoc.18.46

Graphical Abstract
  • material were practically the same as the one of the starting material in all cases. Further, the separation via kinetic resolution in the final reaction step was also examined. The course of the re-esterification was stopped at a conversion of ca 50% and the de values were determined. Unfortunately, no
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Published 14 Apr 2022

Borylated norbornadiene derivatives: Synthesis and application in Pd-catalyzed Suzuki–Miyaura coupling reactions

  • Robin Schulte and
  • Heiko Ihmels

Beilstein J. Org. Chem. 2022, 18, 368–373, doi:10.3762/bjoc.18.41

Graphical Abstract
  • the neighboring methyl group at the reaction center. The novel compounds 2a, 2b, and 3 were identified and characterized by NMR spectroscopy (1H, 13C, COSY, HSQC, HMBC), melting point, and elemental analysis. In addition, the structure of product 2b was supported by high resolution mass spectrometry
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Published 01 Apr 2022

Amamistatins isolated from Nocardia altamirensis

  • Till Steinmetz,
  • Wolf Hiller and
  • Markus Nett

Beilstein J. Org. Chem. 2022, 18, 360–367, doi:10.3762/bjoc.18.40

Graphical Abstract
  • as eluent. Fractions that showed a color change in the CAS assay were pooled and subjected to semipreparative reversed-phase HPLC. This led to the isolation of six CAS active compounds (1–6; Figure 1). The major metabolite 1 (12 mg) was obtained as a slight reddish oil. High resolution (HR) ESIMS
  • conditions. The structures of these natural products were verified by high-resolution mass spectrometry, tandem mass spectrometry as well as 1D and 2D NMR analyses. Their absolute configuration is consistent with the already known amamistatin B according to a comparison of optical rotation values and NOE
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Published 30 Mar 2022

Unexpected chiral vicinal tetrasubstituted diamines via borylcopper-mediated homocoupling of isatin imines

  • Marco Manenti,
  • Leonardo Lo Presti,
  • Giorgio Molteni and
  • Alessandra Silvani

Beilstein J. Org. Chem. 2022, 18, 303–308, doi:10.3762/bjoc.18.34

Graphical Abstract
  • optimized conditions (Table 1, entry 12) followed by flash chromatography, the unprecedented bisoxindole 2a was fully characterized by high-resolution mass spectrometry and by one- and two-dimensional NMR analysis. In particular, from HSQC, HMBC and COSY experiments all single frequencies could be safely
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Published 10 Mar 2022
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