Search results

Search for "NMR spectra" in Full Text gives 2209 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Investigation of a bimetallic terbium(III)/copper(II) chemosensor for the detection of aqueous hydrogen sulfide

  • Parvathy Mini,
  • Michael R. Grace,
  • Genevieve H. Dennison and
  • Kellie L. Tuck

Beilstein J. Org. Chem. 2024, 20, 2818–2826, doi:10.3762/bjoc.20.237

Graphical Abstract
  • magnetic resonance (1H NMR) spectra was recorded on a Bruker DRX400 spectrometer operating at 400 MHz. High-resolution mass spectrometry (HRMS) was performed using a Bruker BioApex 47e FTMS with an analytical electrospray source employing NaI for accurate mass calibration (ESI). UV–vis absorption spectra
PDF
Album
Supp Info
Full Research Paper
Published 05 Nov 2024

Mechanochemical difluoromethylations of ketones

  • Jinbo Ke,
  • Pit van Bonn and
  • Carsten Bolm

Beilstein J. Org. Chem. 2024, 20, 2799–2805, doi:10.3762/bjoc.20.235

Graphical Abstract
  • NMR spectroscopy using 1,2-dichloroethane as internal standard. Optimization of the reaction conditions.a Supporting Information Supporting Information File 12: Experimental procedures, optimization studies, compound characterization data, NMR spectra, and mechanistic investigations. Funding General
PDF
Album
Supp Info
Letter
Published 04 Nov 2024

C–C Coupling in sterically demanding porphyrin environments

  • Liam Cribbin,
  • Brendan Twamley,
  • Nicolae Buga,
  • John E. O’ Brien,
  • Raphael Bühler,
  • Roland A. Fischer and
  • Mathias O. Senge

Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234

Graphical Abstract
  • the existence of this structure in solution was obtained from VT-NMR studies (Figure S51 and Figure S52 in Supporting Information File 1), with asymmetry observed in the β-ethyl CH3 resonances δH = 0.58 and 0.73 ppm and peak broadening in both the aromatic region and the {1H}13C NMR spectra
PDF
Album
Supp Info
Full Research Paper
Published 04 Nov 2024

Access to optically active tetrafluoroethylenated amines based on [1,3]-proton shift reaction

  • Yuta Kabumoto,
  • Eiichiro Yoshimoto,
  • Bing Xiaohuan,
  • Masato Morita,
  • Motohiro Yasui,
  • Shigeyuki Yamada and
  • Tsutomu Konno

Beilstein J. Org. Chem. 2024, 20, 2776–2783, doi:10.3762/bjoc.20.233

Graphical Abstract
  • reaction mechanism. Investigation of the reaction conditions. Supporting Information Supporting Information File 3: Full experimental details, 1H, 13C, 19F NMR spectra of 16a–g and 23a–g, and HPLC charts of racemic as well as chiral compounds 23a–g. Supporting Information File 4: Crystallographic
PDF
Album
Supp Info
Full Research Paper
Published 01 Nov 2024

Synthesis of spiroindolenines through a one-pot multistep process mediated by visible light

  • Francesco Gambuti,
  • Jacopo Pizzorno,
  • Chiara Lambruschini,
  • Renata Riva and
  • Lisa Moni

Beilstein J. Org. Chem. 2024, 20, 2722–2731, doi:10.3762/bjoc.20.230

Graphical Abstract
  • laboratory, and the results will be reported in due course. Experimental General methods 1H, 13C and 19F NMR spectra were recorded on a JEOL 400 spectrometer (at 400 MHz, 101 MHz and 376 MHz, respectively). Unless otherwise stated, NMR spectra were recorded using residual solvent as the internal standard; 1H
  • NMR: TMS = 0.00; (CD3)2SO = 2.50; and 13C NMR: CDCl3 = 77.16; (CD3)2SO = 39.52. Data for 1H NMR spectra are reported as follows: chemical shift (δ ppm), multiplicity, coupling constants (Hz) and integration. Data for 13C NMR spectra are reported in terms of chemical shift (δ ppm). Interpretation of
  • spectra has been made also with the aid of gCOSY, gHSQC and gHMBC experiments. The following abbreviations are used to indicate the multiplicity in NMR spectra: s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet. For some compounds the extra peaks are due to residual of the starting material (<5
PDF
Album
Supp Info
Full Research Paper
Published 29 Oct 2024

Synthesis of benzo[f]quinazoline-1,3(2H,4H)-diones

  • Ruben Manuel Figueira de Abreu,
  • Peter Ehlers and
  • Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2708–2719, doi:10.3762/bjoc.20.228

Graphical Abstract
  • of 1,3-dimethyl-5-phenyl-6-[2-(phenyl)ethynyl]uracil derivatives 5a, 5d, 5f, 5g, 5h, and 5i in dichloromethane (c = 1·10−5 M) at 20 °C. Supporting Information Supporting Information File 20: Copies of NMR spectra. Acknowledgements We are grateful for the technical and analytical support of the
PDF
Album
Supp Info
Full Research Paper
Published 28 Oct 2024

Synthesis of fluoroalkenes and fluoroenynes via cross-coupling reactions using novel multihalogenated vinyl ethers

  • Yukiko Karuo,
  • Keita Hirata,
  • Atsushi Tarui,
  • Kazuyuki Sato,
  • Kentaro Kawai and
  • Masaaki Omote

Beilstein J. Org. Chem. 2024, 20, 2691–2703, doi:10.3762/bjoc.20.226

Graphical Abstract
  • and 3 as new fluorine-containing building blocks. Experimental General information 1H NMR, 19F NMR, and 13C NMR spectra were recorded on JEOL ECZ 400S spectrometers. Chemical shifts of 1H NMR are reported in ppm from tetramethylsilane (TMS) as an internal standard. Chemical shifts of 13C NMR are
  • and various boronic acids 4. Cross-coupling reactions between multihalogenated vinyl ethers 1 and various alkynes 5. Supporting Information Supporting Information File 16: Characterization data for 2b–s and 3b–w, and copies of 1H, 13C, and 19F NMR spectra.
PDF
Album
Supp Info
Full Research Paper
Published 24 Oct 2024

Transition-metal-free decarbonylation–oxidation of 3-arylbenzofuran-2(3H)-ones: access to 2-hydroxybenzophenones

  • Bhaskar B. Dhotare,
  • Seema V. Kanojia,
  • Chahna K. Sakhiya,
  • Amey Wadawale and
  • Dibakar Goswami

Beilstein J. Org. Chem. 2024, 20, 2655–2667, doi:10.3762/bjoc.20.223

Graphical Abstract
  • was extracted with CHCl3 and the 1H NMR spectra were recorded in CDCl3. As can be seen from Figure 4, a gradual increase of the peak at δ 5.3 ppm with concomitant decrease of the peak at δ 11.6 ppm is observed and indicated the gradual formation of THF-hydroperoxide, along with the concomitant
  • over anhydrous Na2SO4. FTIR spectra were recorded as films with a Bruker Tensor II spectrophotometer. The 1H and 13C NMR spectra were recorded with a Varian 500 MHz NMR spectrometer, and were processed using Bruker TOPSPIN software. Melting points (mp) were measured on a Büchi B-540 apparatus. X-ray
  • compounds 4ja, 4fb, and 4ma. Partial 1H NMR spectra of the aliquots (taken at different time intervals) from the reaction mixture. Plausible mechanism for the transition-metal-free decarbonylation–oxidation. UV–vis absorption spectra of selected synthesized compounds 4aa, 4cb, 4eb, and 4fb from 225–500 nm
PDF
Album
Supp Info
Full Research Paper
Published 21 Oct 2024

The scent gland composition of the Mangshan pit viper, Protobothrops mangshanensis

  • Jonas Holste,
  • Paul Weldon,
  • Donald Boyer and
  • Stefan Schulz

Beilstein J. Org. Chem. 2024, 20, 2644–2654, doi:10.3762/bjoc.20.222

Graphical Abstract
  • ) and C-6-methyl (1.56 ppm) and was assigned as the E-diastereomer. This assignment is further supported by the 13C NMR spectra. The major diastereomer shows C-7 at 39.7 ppm, a typical value for (E)-configured aliphatic chains with allylmethyl groups [29], while the (Z)-isomers show values around 30 ppm
  • obtained using a GC 6890 (Agilent Technologies) coupled to a JMS-T100GC mass spectrometer (GC-AccuTOF, JEOL, Japan) using the time-of-flight (70 eV) method. A ZB5 MS column (Phenomenex, 30 m, 0.25 mm i.d. 0.25 µm film thickness) and helium as carrier gas were used. NMR spectra were obtained using Bruker
  • procedures, NMR spectra. Acknowledgements We thank A. Faasen, R. Hartdegen, C. Hollowed, and B. Lawrence for the permission to access to snakes at the Bronx Zoo, New York. The photo in the graphical abstract was taken by Junkyardsparkle from wikipedia.org https://upload.wikimedia.org/wikipedia/commons/c/ca
PDF
Album
Supp Info
Full Research Paper
Published 18 Oct 2024

Efficient modification of peroxydisulfate oxidation reactions of nitrogen-containing heterocycles 6-methyluracil and pyridine

  • Alfiya R. Gimadieva,
  • Yuliya Z. Khazimullina,
  • Aigiza A. Gilimkhanova and
  • Akhat G. Mustafin

Beilstein J. Org. Chem. 2024, 20, 2599–2607, doi:10.3762/bjoc.20.219

Graphical Abstract
  • classes. Experimental 1H and 13C NMR spectra were recorded on a Bruker Avance III 500 MHz spectrometer at 500.13 MHz (1H) and 125.73 MHz (13C) with 5 mm QNP sensors at a constant sample temperature of 298 K. The solvents were DMSO-d6, D2O, CDCl3 and the internal standard was SiMe4. Chemical shifts in the
  • 13C and 1H NMR spectra are given in parts per million (ppm). Elemental analyses were performed on a CHNS Euro-EA 3000 automatic analyzer. Melting points were determined on combinated Boetius tables. IR spectra were obtained on an IR Prestige-21 Shimadzu spectrophotometer in KBr pellets. Freshly
  • (9) on the amount of H2O2.a Supporting Information Supporting Information File 2: NMR spectra of compounds 2, 3, and 6. Funding This work was financially supported by the Ministry of Science and Higher Education of the Russian Federation (State Assignment No. 122031400278-2). Spectral experiments
PDF
Album
Supp Info
Full Research Paper
Published 16 Oct 2024

Synthesis and cytotoxicity studies of novel N-arylbenzo[h]quinazolin-2-amines

  • Battini Veeraiah,
  • Kishore Ramineni,
  • Dabbugoddu Brahmaiah,
  • Nangunoori Sampath Kumar,
  • Hélène Solhi,
  • Rémy Le Guevel,
  • Chada Raji Reddy,
  • Frédéric Justaud and
  • René Grée

Beilstein J. Org. Chem. 2024, 20, 2592–2598, doi:10.3762/bjoc.20.218

Graphical Abstract
  • bromides and other reagents were used as they were received from commercial suppliers, unless otherwise noted. THF and Et2O were dried over sodium-benzophenone and distilled prior to use. 1H NMR spectra were recorded at 300 and 400 MHz, and 13C NMR spectra at 75 and 100 MHz, in CDCl3 or DMSO-d6 using TMS
  • desired targets 4. Cytotoxic studies (IC50 determination) of selected quinazolines 4.a Supporting Information Supporting Information File 2: Supplementary Table S1; spectral and analytical data for compounds 4b–s as well as all copies of 1H and 13C NMR spectra of compounds 4. Acknowledgements We thank
PDF
Album
Supp Info
Full Research Paper
Published 14 Oct 2024

Base-promoted cascade recyclization of allomaltol derivatives containing an amide fragment into substituted 3-(1-hydroxyethylidene)tetronic acids

  • Andrey N. Komogortsev,
  • Constantine V. Milyutin and
  • Boris V. Lichitsky

Beilstein J. Org. Chem. 2024, 20, 2585–2591, doi:10.3762/bjoc.20.217

Graphical Abstract
  • formation of various unidentified byproducts. The obtained tetronic acids 4 are solid crystalline compounds, whose structure was proved by 1H, 13C NMR spectroscopy and high-resolution mass spectrometry. The 1H NMR spectra of the synthesized products contain characteristic signals of protons of the methyl
  • Unless otherwise stated, all starting chemicals were commercially available and were used as received. The starting compounds 1 were prepared by a procedure described in the literature [33][34]. NMR spectra were recorded with Bruker AM 300 (300 MHz) in DMSO-d6. Chemical shifts (ppm) are given relative to
  • , copies of NMR spectra, X-ray crystallographic data and refinement details. Supporting Information File 142: Analytical data of all compounds 4, 7 and 9. Acknowledgements Crystal structure determination was performed in the Department of Structural Studies of Zelinsky Institute of Organic Chemistry
PDF
Album
Supp Info
Full Research Paper
Published 14 Oct 2024

Transition-metal-free synthesis of arylboronates via thermal generation of aryl radicals from triarylbismuthines in air

  • Yuki Yamamoto,
  • Yuki Konakazawa,
  • Kohsuke Fujiwara and
  • Akiya Ogawa

Beilstein J. Org. Chem. 2024, 20, 2577–2584, doi:10.3762/bjoc.20.216

Graphical Abstract
  • without further purification. All solvents were used without distillation. Triarylbismuthines 1 were synthesized according to the previously reported procedures [62]. 1H, 13C{1H}, and 11B NMR spectra were recorded in CDCl3 using a Bruker AVANCE III HD 500 spectrometer at 500, 126, and 160 MHz
  • File 138: Investigation of the boron residue in the crude mixture by 11B NMR measurement, characterization data of the compounds, and copies of 1H NMR and 13C{1H} NMR spectra. Acknowledgements We acknowledged Dr. Tran Dat Phuc and Mr. Soichiro Mita (Osaka Prefecture University) for their initial
PDF
Album
Supp Info
Full Research Paper
Published 11 Oct 2024

Anion-dependent ion-pairing assemblies of triazatriangulenium cation that interferes with stacking structures

  • Yohei Haketa,
  • Takuma Matsuda and
  • Hiromitsu Maeda

Beilstein J. Org. Chem. 2024, 20, 2567–2576, doi:10.3762/bjoc.20.215

Graphical Abstract
  • further purification unless otherwise stated. According to the previous procedure [30], 4,8,12-tris(2,6-dimethylphenyl)-4,8,12-triazatriangulenium as a Cl− ion pair, 2+-Cl−, was prepared. NMR spectra used in the characterization of products were recorded on a JEOL ECA-600 600 MHz spectrometer. All NMR
  • NMR spectra of new ion pairs, details for crystal structures, and theoretical calculations. Acknowledgements Theoretical calculations were partially performed at the Research Center for Computational Science, Okazaki, Japan (Projects: 22-IMS-C077, 23-IMS-C069, and 24-IMS-C067). The synchrotron
  • spectra were referenced to residual solvent. UV–visible absorption spectra were recorded on a Hitachi U-4500 spectrometer. Fluorescence spectra were recorded on a Hitachi F-4500 fluorescence spectrometer. MALDI–TOF MS was recorded on a Shimadzu Axima-CFRplus. TLC analyses were carried out on aluminum
PDF
Album
Supp Info
Full Research Paper
Published 10 Oct 2024

Visible-light-mediated flow protocol for Achmatowicz rearrangement

  • Joachyutharayalu Oja,
  • Sanjeev Kumar and
  • Srihari Pabbaraja

Beilstein J. Org. Chem. 2024, 20, 2493–2499, doi:10.3762/bjoc.20.213

Graphical Abstract
  • mechanism for the photochemically induced Achmatowicz rearrangement. Strategies for Achmatowicz rearrangement. Optimization of continuous flow Achmatowicz reactiona. Supporting Information Supporting Information File 133: Experimental section and NMR spectra. Supporting Information File 134: Video of the
PDF
Album
Supp Info
Letter
Published 08 Oct 2024

Photoredox-catalyzed intramolecular nucleophilic amidation of alkenes with β-lactams

  • Valentina Giraldi,
  • Giandomenico Magagnano,
  • Daria Giacomini,
  • Pier Giorgio Cozzi and
  • Andrea Gualandi

Beilstein J. Org. Chem. 2024, 20, 2461–2468, doi:10.3762/bjoc.20.210

Graphical Abstract
  • characterization, spectroscopic data for new compounds, and copies of NMR spectra. Funding P. G. C., D. G., and A. G. acknowledge the University of Bologna for financial support. MIUR national project (PRIN 2017 ID: 20174SYJAF) SURSUMCAT “Raising up Catalysis for Innovative Developments” and European Union’s
PDF
Album
Supp Info
Full Research Paper
Published 01 Oct 2024

Hypervalent iodine-mediated cyclization of bishomoallylamides to prolinols

  • Smaher E. Butt,
  • Konrad Kepski,
  • Jean-Marc Sotiropoulos and
  • Wesley J. Moran

Beilstein J. Org. Chem. 2024, 20, 2455–2460, doi:10.3762/bjoc.20.209

Graphical Abstract
  • Information File 120: Experimental procedures, compound characterization data, copies of NMR spectra, cartesian coordinates and energies of calculated structures. Acknowledgements We thank Professor Mark Heron for his useful discussions and Dr Neil McLay for his NMR expertise. We also acknowledge Joshua
PDF
Album
Supp Info
Full Research Paper
Published 30 Sep 2024

Synthesis and conformational analysis of pyran inter-halide analogues of ᴅ-talose

  • Olivier Lessard,
  • Mathilde Grosset-Magagne,
  • Paul A. Johnson and
  • Denis Giguère

Beilstein J. Org. Chem. 2024, 20, 2442–2454, doi:10.3762/bjoc.20.208

Graphical Abstract
  • results showed no qualitative difference. Entries marked – are below the 0.50 kcal/mol threshold. Supporting Information Supporting Information File 118: Experimental and analytical data, crystal structure determination and NMR spectra. Funding This work was supported by the Natural Sciences and
PDF
Album
Supp Info
Full Research Paper
Published 27 Sep 2024

Phenylseleno trifluoromethoxylation of alkenes

  • Clément Delobel,
  • Armen Panossian,
  • Gilles Hanquet,
  • Frédéric R. Leroux,
  • Fabien Toulgoat and
  • Thierry Billard

Beilstein J. Org. Chem. 2024, 20, 2434–2441, doi:10.3762/bjoc.20.207

Graphical Abstract
  • experimental and analytical data and NMR spectra. Acknowledgements The NMR Center and the Mass Spectrometry Center are acknowledged for their analysis. Funding The authors are grateful to the French National Research Agency (ANR; grant no. 20-CE07-0004-02, Ap-PET-I). The CNRS, the French Ministry of Education
PDF
Album
Supp Info
Full Research Paper
Published 26 Sep 2024

Facile preparation of fluorine-containing 2,3-epoxypropanoates and their epoxy ring-opening reactions with various nucleophiles

  • Yutaro Miyashita,
  • Sae Someya,
  • Tomoko Kawasaki-Takasuka,
  • Tomohiro Agou and
  • Takashi Yamazaki

Beilstein J. Org. Chem. 2024, 20, 2421–2433, doi:10.3762/bjoc.20.206

Graphical Abstract
  • during the lactone-forming process. Their close structural resemblance led to a significant peak overlap both in the 1H and 19F NMR spectra which made it difficult to obtain their exact ratio and thus, the combined 19F NMR yields were shown in Table 4. Separation of these two compounds was eventually
  • experimental and analytical details, copies of NMR spectra for new compounds, and crystallographic data.
  • , 2856, 1720, 1469, 1291, 1176, 1146, 899, 841, 719, 643 cm−1; HRMS–FAB+ (m/z): [M + H]+ calcd for C14H26F3O2, 283.1879; found, 283.1893. Crystallographic structure of the epoxy ring-opening products by PhCH(NH2)Me (3bd) and PhCH2SH (4ba). Crystallographic structure of anti,syn-8a. A part of 13C NMR
PDF
Album
Supp Info
Full Research Paper
Published 25 Sep 2024

Efficient one-step synthesis of diarylacetic acids by electrochemical direct carboxylation of diarylmethanol compounds in DMSO

  • Hisanori Senboku and
  • Mizuki Hayama

Beilstein J. Org. Chem. 2024, 20, 2392–2400, doi:10.3762/bjoc.20.203

Graphical Abstract
  • a novel, efficient, facile, and green organic method. Experimental General information 1H (400 MHz) and 13C (100 MHz) NMR spectra were recorded in CDCl3 or DMSO-d6 with a JEOL JNM-ECS400 FT NMR spectrometer. The chemical shifts δ are given in ppm with tetramethylsilane (δ 0 ppm) or DMSO (δ 2.50 ppm
  • Information Supporting Information File 102: NMR spectra. Acknowledgements 1H and 13C NMR spectra were measured at Instrumental Analysis Support Office, Frontier Chemistry Center, Faculty of Engineering, Hokkaido University. The authors are grateful for the support. Funding This work was partly supported by
PDF
Album
Supp Info
Full Research Paper
Published 20 Sep 2024

Tandem diazotization/cyclization approach for the synthesis of a fused 1,2,3-triazinone-furazan/furoxan heterocyclic system

  • Yuri A. Sidunets,
  • Valeriya G. Melekhina and
  • Leonid L. Fershtat

Beilstein J. Org. Chem. 2024, 20, 2342–2348, doi:10.3762/bjoc.20.200

Graphical Abstract
  • obtained. Thus, we have demonstrated that the terminal nitrogen atom in the diazonium fragment of intermediate 9 becomes the N5 atom of compound 8 (corresponding 15N NMR spectra are provided in Supporting Information File 1). To explore the potential application of the obtained compounds 1 and 7, we
PDF
Album
Supp Info
Full Research Paper
Published 16 Sep 2024

Stereoselective mechanochemical synthesis of thiomalonate Michael adducts via iminium catalysis by chiral primary amines

  • Michał Błauciak,
  • Dominika Andrzejczyk,
  • Błażej Dziuk and
  • Rafał Kowalczyk

Beilstein J. Org. Chem. 2024, 20, 2313–2322, doi:10.3762/bjoc.20.198

Graphical Abstract
  • cyclohexenone. Addition of bisthiomalonates 1–3 to cyclopentenone. Acyclic enone in reactions with thiomalonates 1–4. Reaction of β-ketothioesters with acceptor E1. Supporting Information Supporting Information File 94: Experimental and analytical data, crystallographic information and NMR spectra
PDF
Album
Supp Info
Full Research Paper
Published 12 Sep 2024

Hydrogen-bond activation enables aziridination of unactivated olefins with simple iminoiodinanes

  • Phong Thai,
  • Lauv Patel,
  • Diyasha Manna and
  • David C. Powers

Beilstein J. Org. Chem. 2024, 20, 2305–2312, doi:10.3762/bjoc.20.197

Graphical Abstract
  • (denoted by asterisk *) of HFIP in the presence of iminoiodinane 2c suggesting hydrogen bonding observed in 1H NMR spectra (CD3CN) of: 8.0 mM 2c with no HFIP (blue line), 8.0 mM 2c with 32 mM HFIP (green line), 4.0 mM of 4-(trifluoromethyl)benzenesulfonamide with 32 mM HFIP (purple line), only 32 mM HFIP
PDF
Album
Supp Info
Full Research Paper
Published 11 Sep 2024

Deuterated reagents in multicomponent reactions to afford deuterium-labeled products

  • Kevin Schofield,
  • Shayna Maddern,
  • Yueteng Zhang,
  • Grace E. Mastin,
  • Rachel Knight,
  • Wei Wang,
  • James Galligan and
  • Christopher Hulme

Beilstein J. Org. Chem. 2024, 20, 2270–2279, doi:10.3762/bjoc.20.195

Graphical Abstract
  • . Optimization of deuterated Leuckart–Wallach reactiona. Microsomal stability package of deuterated and non-deuterated dihydropyridines. Supporting Information Supporting Information File 86: Experimental and analytical data and copies of NMR spectra. Acknowledgements We thank the UA mass spectrometry and NMR
PDF
Album
Supp Info
Full Research Paper
Published 06 Sep 2024
Other Beilstein-Institut Open Science Activities