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Search for "19F)" in Full Text gives 313 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Formal preparation of regioregular and alternating thiophene–thiophene copolymers bearing different substituents

  • Atsunori Mori,
  • Keisuke Fujita,
  • Chihiro Kubota,
  • Toyoko Suzuki,
  • Kentaro Okano,
  • Takuya Matsumoto,
  • Takashi Nishino and
  • Masaki Horie

Beilstein J. Org. Chem. 2020, 16, 317–324, doi:10.3762/bjoc.16.31

Graphical Abstract
  • MHz), 19F NMR (376 MHz), and 13C{1H} NMR (100 MHz) spectra were measured on a JEOL ECZ400 spectrometer as a CDCl3 solution, unless otherwise noted. The chemical shifts were expressed in ppm with CHCl3 (7.26 ppm for 1H), C6F6 (−164.9 ppm for 19F), or CDCl3 (77.16 ppm for 13C) as internal standards. IR
  • Hz, 2H), 6.79 (s, 1H), 6.91 (d, J = 5.0 Hz, 1H), 7.17 (d, J = 5.0 Hz, 1H); 13C{1H} NMR (100 MHz, CDCl3) δ 0.4, 2.1, 18.3, 20.5 (br), 23.4, 27.4, 29.0, 30.4 (t, J = 22 Hz), 34.5, 124.3, 125.1, 126.0, 129.7, 130.2, 133.6, 137.6, 140.3; 19F NMR (376 MHz, C6F6) δ −129.2, −127.6, −117.6, −84.2; IR (ATR
  • , 1H); 13C{1H} NMR (100 MHz, CDCl3) δ −0.2, 2.0, 17.6, 20.5 (br), 23.1, 27.4, 29.0, 30.4 (t, J = 22 Hz), 34.3, 124.3, 125.1, 126.0, 129.7, 130.2, 133.6, 137.6, 140.2; 19F NMR (376 MHz, C6F6) δ −129.2, −127.6, −117.6, −84.2; IR (ATR): 2958, 1252, 1233, 1167, 1134, 1046, 870, 841, 800, 783, 754, 719, 689
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Published 05 Mar 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
  • conditions via a three-step reaction. The solution-state 1H NMR spectra of 6 showed a strong intramolecular interaction between F and H5 (JFH = 2.6 Hz) and 13C NMR suggested that this C–F···H–C coupling is a through-space interaction. The 2D 19F-{1H} HOESY and 1H-{19F} 1D experiments were done to confirm
  • ). The H5 signal was expected to be a doublet (not a dd) due to 3J coupling to H6, since an H,H-COSY experiment does not show coupling between H5 and H8 (Figure S9, Supporting Information File 1). It became clear that the splitting of the signal from H5 was due to coupling with the 19F atom by comparing
  • the spectra from the 1H and 1H-{19F} experiments (Figure 1) which showed the H5 peak as a doublet with 19F decoupling. While the doublet-of-doublets signal for H5 collapses into a doublet with 19F decoupling, there are no significant changes in the line-shape for the signal of H3 with 19F decoupling
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Published 10 Feb 2020

Efficient method for propargylation of aldehydes promoted by allenylboron compounds under microwave irradiation

  • Jucleiton J. R. Freitas,
  • Queila P. S. B. Freitas,
  • Silvia R. C. P. Andrade,
  • Juliano C. R. Freitas,
  • Roberta A. Oliveira and
  • Paulo H. Menezes

Beilstein J. Org. Chem. 2020, 16, 168–174, doi:10.3762/bjoc.16.19

Graphical Abstract
  • propargylating agent in a very regioselective way [36][37]. Thus, allenylboronic acid pinacol ester (1) was converted into the corresponding trifluoroborate using the procedure described by Lloyd-Jones and co-worker [38]. The desired product 4 was obtained in good yield and characterized by 1H, 13C, 11B and 19F
  • solvents.a Supporting Information Supporting Information File 252: Experimental procedures and 1H, 13C, 11B and 19F NMR spectra for all synthesized compounds. Funding This work was jointly supported by grants from CNPq and FACEPE.
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Published 04 Feb 2020

Fluorinated maleimide-substituted porphyrins and chlorins: synthesis and characterization

  • Valentina A. Ol’shevskaya,
  • Elena G. Kononova and
  • Andrei V. Zaitsev

Beilstein J. Org. Chem. 2019, 15, 2704–2709, doi:10.3762/bjoc.15.263

Graphical Abstract
  • ) or Ni(II) with N-propargylmaleimide via the CuAAC click reaction to afford fluorinated porphyrin–triazole–maleimide conjugates. New maleimide derivatives were isolated in reasonable yields and identified by UV–vis, 1H NMR, 19F NMR spectroscopy and mass-spectrometry. Keywords: chlorin; maleimide
  • was transformed into the corresponding maleimide 12 in 25% yield on the reaction with maleic anhydride according to the standard procedure. Chlorin 12 was metalated with Zn(OAc)2/CHCl3/MeOH giving chlorin 13 in 92% yield. (Scheme 2). All prepared compounds have been structurally identified by 1H, 19F
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Published 13 Nov 2019

Synthesis of aryl-substituted thieno[3,2-b]thiophene derivatives and their use for N,S-heterotetracene construction

  • Nadezhda S. Demina,
  • Nikita A. Kazin,
  • Nikolay A. Rasputin,
  • Roman A. Irgashev and
  • Gennady L. Rusinov

Beilstein J. Org. Chem. 2019, 15, 2678–2683, doi:10.3762/bjoc.15.261

Graphical Abstract
  • Crystallographic Data Centre via https://www.ccdc.cam.ac.uk/data_request/cif. Supporting Information File 569: Experimental section and copies of 1H, 13C and 19F NMR spectra of new compounds. Supporting Information File 570: Crystal data of 7d. Acknowledgements This study was supported by the Russian Foundation
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Published 12 Nov 2019

1,5-Phosphonium betaines from N-triflylpropiolamides, triphenylphosphane, and active methylene compounds

  • Vito A. Fiore,
  • Chiara Freisler and
  • Gerhard Maas

Beilstein J. Org. Chem. 2019, 15, 2603–2611, doi:10.3762/bjoc.15.253

Graphical Abstract
  • triphenylphosphane and N-triflyl-propiolanilide 1a in dichloromethane yielded a product mixture, from which only N-phenyltriflylamide (HN(Ph)Tf; 19F NMR: δ −76.5 ppm rel. to C6F6) could be extracted, the remainder being undefined oligomeric/polymeric material. However, when an N-triflylpropiolamide 1a–e (1.03 molar
  • Information Supporting Information File 640: Experimental procedures, characterization data, NMR spectra (1H, 13C, 31P, 19F) and IR spectra for the synthesized compounds, and data for the X-ray crystal structure determinations.
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Published 01 Nov 2019

Mono- and bithiophene-substituted diarylethene photoswitches with emissive open or closed forms

  • A. Lennart Schleper,
  • Mariano L. Bossi,
  • Vladimir N. Belov and
  • Stefan W. Hell

Beilstein J. Org. Chem. 2019, 15, 2344–2354, doi:10.3762/bjoc.15.227

Graphical Abstract
  • DAE 4 could not be isolated by column chromatography on regular silica gel. Instead, monoiodide 4 was obtained in 14% yield as colorless solid after preparative HPLC on a reversed phase (C18) column and lyophilization. The constitution and structure of 4 was confirmed by HRMS, 1H and 19F NMR
  • closed form (formed by handling in the lab not fully protected from light) were detected by HPLC (Figure S33 in Supporting Information File 1). The constitution, structures, and purities of the final products were confirmed by HRMS, 1H and 19F NMR spectroscopy, as well as analytical HPLC. Saponification
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Published 01 Oct 2019

Aggregation-induced emission effect on turn-off fluorescent switching of a photochromic diarylethene

  • Luna Kono,
  • Yuma Nakagawa,
  • Ayako Fujimoto,
  • Ryo Nishimura,
  • Yohei Hattori,
  • Toshiki Mutai,
  • Nobuhiro Yasuda,
  • Kenichi Koizumi,
  • Satoshi Yokojima,
  • Shinichiro Nakamura and
  • Kingo Uchida

Beilstein J. Org. Chem. 2019, 15, 2204–2212, doi:10.3762/bjoc.15.217

Graphical Abstract
  • were used without further purification. Melting points were determined on a Yanaco MP-500D melting point apparatus and are uncorrected. 1H (400 MHz), 13C (100 MHz) and 19F NMR (376 MHz) spectra were recorded on a JEOL JNM-400 spectrometer at ambient temperature. The splitting patterns are designated as
  • , 123.9, 123.0, 122.5, 122.2, 121.7, 121.2, 119.4, 117.5, 113.2, 111.0, 55.5, 14.7, 14.77; 19F NMR (376 MHz, CDCl3, ppm) δ −113.1 (s, 2F), −113.3 (s, 2F), −135.0 (s, 2F); HRMS (MALDI–TOF) m/z: calcd for C35H24F6N2OS2, 666.1234; found, 666.1229. Diarylethene (1o) To 5 mL of dichloromethane anhydrous
  • , 142.8, 142.6, 142.1, 141.4, 137.7, 133.4, 130.1, 129.2, 129.2, 128.2, 126.3, 125.9, 125.9, 125.8, 125.8, 124.6, 123.7, 122.5, 121.5, 120.7, 119.2, 117.9, 117.0, 116.1, 107.3, 14.7, 14.7; 19F NMR (376 MHz, CDCl3, ppm) δ −113.1 (s, 2F), −113.3 (s, 2F), −135.0 (s, 2F); HRMS (MALDI–TOF) m/z: calcd for
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Published 20 Sep 2019

Friedel–Crafts approach to the one-pot synthesis of methoxy-substituted thioxanthylium salts

  • Kenta Tanaka,
  • Yuta Tanaka,
  • Mami Kishimoto,
  • Yujiro Hoshino and
  • Kiyoshi Honda

Beilstein J. Org. Chem. 2019, 15, 2105–2112, doi:10.3762/bjoc.15.208

Graphical Abstract
  • ), coupling constants, integration. 13C NMR spectra were recorded on a Bruker DRX-500 (126 MHz) or a JEOL JNM ECA-500 (126 MHz) spectrometer with complete proton decoupling. Chemical shifts are reported in ppm with the solvent resonance as the internal standard (CDCl3: δ 77.0). 19F NMR spectra were recorded
  • , 6H); 13C NMR (126 MHz, CDCl3) δ 168.3. 165.5. 165.2. 147.8. 142.2. 127.2. 127.0. 125.6. 116.9. 101.8. 101.4. 57.7. 56.7; 19F NMR (376 MHz, CDCl3) δ −81.3; IR (ATR): 1585, 1219, 1143, 1026, 634 cm−1; HRMS (ESI+) m/z: [M]+ calcd for C23H21O4S, 393.1155; found, 393.1171; anal. calcd for C24H21F3O7S2: C
  • Hz, 1H), 6.93 (dd, J = 7.1, 1.1 Hz, 1H), 6.43 (d, J = 2.2 Hz, 2H), 4.15 (s, 6H), 2.96 (s, 6H); 13C NMR (126 MHz, CDCl3) δ 168.4, 165.2, 164.7, 147.6, 140.7, 132.1, 132.0, 128.2, 127.5, 126.4, 125.9, 125.0, 124.4, 121.3, 117.6, 102.0, 101.5, 57.7, 56.6; 19F NMR (376 MHz, CDCl3) δ −81.3; IR (ATR): 1593
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Published 05 Sep 2019

1,2,3,4-Tetrahydro-1,4,5,8-tetraazaanthracene revisited: properties and structural evidence of aromaticity loss

  • Arnault Heynderickx,
  • Sébastien Nénon,
  • Olivier Siri,
  • Vladimir Lokshin and
  • Vladimir Khodorkovsky

Beilstein J. Org. Chem. 2019, 15, 2059–2068, doi:10.3762/bjoc.15.203

Graphical Abstract
  • , 146.58; 19F NMR (DMSO-d6) δ 148; HRMS (ESIMS) m/z: [M2+]; calcd. for C12H16N42+ 216.1364 108.0682; found, 108.0683. 1,4-Diacetyl)-1,2,3,4-tetrahydropyrazino[2,3-g]quinoxaline (9): 1,2,3,4-Tetrahydropyrazino[2,3-g]quinoxaline (3, 500 mg, 2.68 mmol) was added to 20 mL of acetic anhydride and the mixture
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Published 28 Aug 2019

Synthesis and anion binding properties of phthalimide-containing corona[6]arenes

  • Meng-Di Gu,
  • Yao Lu and
  • Mei-Xiang Wang

Beilstein J. Org. Chem. 2019, 15, 1976–1983, doi:10.3762/bjoc.15.193

Graphical Abstract
  • = 6.4 Hz, 6H); 19F NMR (376 MHz, DMSO-d6, 25 °C) δ 59.8; 13C NMR (101 MHz, MeCN-d3, 25 °C) δ 167.1, 164.5, 154.8, 145.0, 144.2, 131.2, 125.9, 124.7 (q,1J(C, F) = 271.6 Hz), 124.5, 120.9 (q, 2J(C, F) = 31.8 Hz), 117.1, 36.5, 35.5, 28.2; IR (KBr, cm−1) ν: 3372, 3080, 2937, 1775, 1717, 1603, 1545, 1382
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Published 21 Aug 2019

The cyclopropylcarbinyl route to γ-silyl carbocations

  • Xavier Creary

Beilstein J. Org. Chem. 2019, 15, 1769–1780, doi:10.3762/bjoc.15.170

Graphical Abstract
  • . Stereochemistry of the alcohol 58 was established by long-range 19F coupling to the cis-trimethylsilyl group hydrogens (JH-F = 0.9 Hz). Long-range 19F coupling to the TMS methyl groups of 58 was also observed in the 13C NMR spectrum (JC-F = 2.1 Hz) [64][65]. This long-range 19F coupling is not observed when the
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Published 24 Jul 2019

Fluorine-containing substituents: metabolism of the α,α-difluoroethyl thioether motif

  • Andrea Rodil,
  • Alexandra M. Z. Slawin,
  • Nawaf Al-Maharik,
  • Ren Tomita and
  • David O’Hagan

Beilstein J. Org. Chem. 2019, 15, 1441–1447, doi:10.3762/bjoc.15.144

Graphical Abstract
  • 19F NMR spectrum consistent with non-equivalence of the fluorines, immediately indicative of sulfoxide formation. Isolation and subsequent 1H and 19F NMR analyses as well as high-resolution mass spectrometry secured the identity of these metabolites as sulfoxides 6 and 7 and sulfone 8. The structure
  • naphthalene ring, as summarised in Scheme 3. These metabolites were isolated by reversed-phase HPLC and characterised by 1H and 19F NMR and mass spectrometry. This identified sulfoxides 11 and 12 as the major metabolites and a trace amount of a minor sulfone which had the general structure 13 as determined by
  • hydrolytic lability of the analogous oxygen ethers. By way of example α,α-difluoroethyl ether 14 [18] was incubated with cultures of C. elegans under the standardised conditions, as illustrated in Scheme 4. 19F NMR of the extract indicated a trace of residual starting material with one major metabolite which
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Published 28 Jun 2019

Stereo- and regioselective hydroboration of 1-exo-methylene pyranoses: discovery of aryltriazolylmethyl C-galactopyranosides as selective galectin-1 inhibitors

  • Alexander Dahlqvist,
  • Axel Furevi,
  • Niklas Warlin,
  • Hakon Leffler and
  • Ulf J. Nilsson

Beilstein J. Org. Chem. 2019, 15, 1046–1060, doi:10.3762/bjoc.15.102

Graphical Abstract
  • stated in the procedure. NMR spectra were collected on a Bruker Ultrashield Plus/Avance II 400 MHz spectrometer. 1H NMR spectra were recorded at 400 MHz and 13C NMR spectra at 100 MHz with residual solvent signals as references. 19F NMR spectra were recorded at 376 MHz. Stereochemistry was assigned
  • = 11.4 Hz, 7.2 Hz, 1H, H7), 3.69 (dd, J = 11.5 Hz, 4.6 Hz, 1H, H7), 3.60–3.49 (m, 4H); 13C NMR (100 MHz, CD3OD) δ 161.6, 146.2, 127.4, 127.3, 126.6, 122.4, 115.5, 115.3, 79.0, 78.6, 74.7, 69.4, 68.4, 61.5, 51.6; 19F NMR (376 MHz, CD3OD) δ −115.54; HRMS (m/z): [M + H]+ calcd for 340.1306; found, 340.1309
  • ), 3.90 (dd, J = 2.9 Hz, 0.9 Hz, 1H, H5), 3.79 (dd, J = 11.2 Hz, 6.9 Hz, 1H, H7), 3.70 (dd, J = 11.6 Hz, 4.71 Hz, 1H, H7), 3.60–3.48 (m, 4H); 13C NMR (100 MHz, CD3OD) δ 164.5, 146.2, 132.9, 130.5, 122.9, 121.1, 114.4, 111.9, 78.9, 78.7, 74.7 69.4, 68.4, 61.5, 51.5; 19F NMR (376 MHz, CD3OD) δ −114.83; HRMS
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Published 07 May 2019

Halogen bonding and host–guest chemistry between N-alkylammonium resorcinarene halides, diiodoperfluorobutane and neutral guests

  • Fangfang Pan,
  • Mohadeseh Dashti,
  • Michael R. Reynolds,
  • Kari Rissanen,
  • John F. Trant and
  • Ngong Kodiah Beyeh

Beilstein J. Org. Chem. 2019, 15, 947–954, doi:10.3762/bjoc.15.91

Graphical Abstract
  • nature of the halogen bond assembly. The crystal lattice of 1 contains two structurally different dimeric assemblies A and B, formally resulting in the mixture of a capsular dimer and a dimeric pseudo-capsule. 1H and 19F NMR analyses supports the existence of these halogen-bonded complexes and enhanced
  • –NH2 protons of the NARXs are expected [32][33]. Additionally, NARXs are also known to cooperatively bind small guest molecules such as mono- and diamides [42][43]. Consequently, we used 1H and 19F NMR spectroscopy to study the XB assemblies formed between Hex-NARBr 1 and 1,4-diiodooctafluorobutane (5
  • acetonitrile. The 1H and 19F NMR spectra of all these samples were recorded at 298 K and analyzed. In the 19F NMR analyses, the fluorine signals of the XB donor DIOFB were monitored. In all cases, minor upfield shifts of the fluorines on the terminal carbons were observed (0.12 ppm in 1·DIOFB, 0.13 ppm in 1
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Published 18 Apr 2019

Conformational signature of Ishikawa´s reagent using NMR information from diastereotopic fluorines

  • Laize A. F. Andrade,
  • Lucas A. Zeoly,
  • Rodrigo A. Cormanich and
  • Matheus P. Freitas

Beilstein J. Org. Chem. 2019, 15, 506–512, doi:10.3762/bjoc.15.44

Graphical Abstract
  • interactions (nN → σ*C–F), which can be demonstrated by means of 19F chemical shifts. The results were rationalized with the aid of theoretical calculations and natural bond orbital (NBO) analysis, allowing for the evaluation of competing steric, electrostatic and hyperconjugative interactions. Keywords
  • enhance the fluoride character of the fluorine involved in such interaction. Because of the negative charge on the fluorine in the resonance structure derived from the generalized anomeric effect, a shielding effect is expected for this fluorine. The 19F NMR assignment of the diastereotopic fluorines was
  • possible considering the 3JH,F(1) SSCC earlier reported, and comparing the 19F and 19F{1H} NMR experiments: the more shielded diastereotopic fluorine corresponds to Fpro-S, thus yielding 1b as the dominant conformation. Such a shielding effect decreases on going from cyclohexane (−89.4 ppm) to pyridine
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Published 20 Feb 2019

Sigmatropic rearrangements of cyclopropenylcarbinol derivatives. Access to diversely substituted alkylidenecyclopropanes

  • Guillaume Ernouf,
  • Jean-Louis Brayer,
  • Christophe Meyer and
  • Janine Cossy

Beilstein J. Org. Chem. 2019, 15, 333–350, doi:10.3762/bjoc.15.29

Graphical Abstract
  • achieved in the presence of Pd/C as a catalyst. Concomitant hydrogenolysis of two carbon–chlorine bonds also took place under these conditions and a 71:29 diastereomeric mixture of the monochloracetamides 19f/19’f was obtained (41%). The rather small difference of steric hindrance between the methyl and
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Published 05 Feb 2019

Unexpected loss of stereoselectivity in glycosylation reactions during the synthesis of chondroitin sulfate oligosaccharides

  • Teresa Mena-Barragán,
  • José L. de Paz and
  • Pedro M. Nieto

Beilstein J. Org. Chem. 2019, 15, 137–144, doi:10.3762/bjoc.15.14

Graphical Abstract
  • leads to the selective formation of the desired 1,2-trans glycosidic linkages and can be easily removed at the end of the synthesis [7][8][36][42]. Moreover, 19F NMR experiments can be employed to assist in the analysis and monitoring of reactions involving N-TFA building blocks. First, we describe the
  • -2C (δ = 4.50 ppm in 14α; δ = 3.52–3.43 ppm in 14β). The value of the coupling constant J1,2 in ring C confirmed the configuration of the new glycosidic linkage (J1,2 = 3.2 Hz in 14α; J1,2 = 8.2–8.5 Hz in 14β). 19F NMR spectra also showed clear differences in the chemical shifts for the
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Published 15 Jan 2019

A convenient and practical synthesis of β-diketones bearing linear perfluorinated alkyl groups and a 2-thienyl moiety

  • Ilya V. Taydakov,
  • Yuliya M. Kreshchenova and
  • Ekaterina P. Dolotova

Beilstein J. Org. Chem. 2018, 14, 3106–3111, doi:10.3762/bjoc.14.290

Graphical Abstract
  • compounds 3a–g and 5. Supporting Information File 522: Copies of 19F and 13C NMR spectra and LR mass spectra of compounds 3a–g and 5. Acknowledgements We are grateful to the Russian Science Foundation (grant No. 19-13-00272) for supporting the synthetic part of this work. Financial support for the NMR and
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Published 27 Dec 2018

6’-Fluoro[4.3.0]bicyclo nucleic acid: synthesis, biophysical properties and molecular dynamics simulations

  • Sibylle Frei,
  • Andrei Istrate and
  • Christian J. Leumann

Beilstein J. Org. Chem. 2018, 14, 3088–3097, doi:10.3762/bjoc.14.288

Graphical Abstract
  • :2, rt, 19.5 h, 44%; f) CEP-Cl, DIPEA, THF, rt, 75 min, 43%. Tm and ΔTm/mod data from UV-melting curves (260 nm) of ON1–7 in duplexes with complementary DNA and RNA. Supporting Information Additional tables and figures, the experimental part, as well as copies of the NMR spectra (1H, 13C, 19F, 31P
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Published 20 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
  • at 400 MHz; 13C NMR at 101 MHz) or a JEOL–ECA500 spectrometer (19F NMR at 471 MHz). Chemical shifts are reported in ppm relative to the internal standard signal (0 ppm for Me4Si in CDCl3) for 1H NMR and the solvent signal (77.16 ppm for CDCl3) for 13C NMR. Data are presented as follows: chemical
  • , 24.34, 24.29; 19F NMR (471 MHz, CDCl3) δ −126.3; HRMS–APCI+ (m/z): [M + H]+ calcd for C47H54FN2O8, 793.3859; found, 793.3859. Synthesis of bis(salen) (R,R,S,S)-8: The crude product was obtained from (S,S)-1,2-cyclohexanediamine monohydrochloride (28 mg, 0.19 mmol), 3-tert-butyl-5-fluoro-2
  • ), 72.8, 72.0, 35.1, 35.0, 33.2, 33.0, 29.3, 29.1, 24.35, 24.29; 19F NMR (471 MHz, CDCl3) δ −126.3; HRMS–APCI+ (m/z): [M + H]+ calcd for C64H77F2N4O8+, 1067.5704; found, 1067.5697. Synthesis of bis(salen) (R,R,R,R)-8: The crude product was obtained from (R,R)-1,2-cyclohexanediamine monohydrochloride (0.10
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Published 05 Nov 2018

Cobalt- and rhodium-catalyzed carboxylation using carbon dioxide as the C1 source

  • Tetsuaki Fujihara and
  • Yasushi Tsuji

Beilstein J. Org. Chem. 2018, 14, 2435–2460, doi:10.3762/bjoc.14.221

Graphical Abstract
  • corresponding product 19f-Me in good yield. Methyl, ethyl, and tert-butyl acrylates 18b, 18c, and 18d, respectively, also afforded the corresponding products. The product of the reaction with acrylamide 18e was also obtained. Scheme 19 shows a plausible reaction mechanism for this four-component coupling
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Published 19 Sep 2018

Efficient catalytic alkyne metathesis with a fluoroalkoxy-supported ditungsten(III) complex

  • Henrike Ehrhorn,
  • Janin Schlösser,
  • Dirk Bockfeld and
  • Matthias Tamm

Beilstein J. Org. Chem. 2018, 14, 2425–2434, doi:10.3762/bjoc.14.220

Graphical Abstract
  • from [NaW2Cl7(THF)5] [86]. The 13C and 19F NMR spectra are also consistent with literature values. Crystals of W2F3 suitable for X-ray diffraction analysis were obtained upon cooling a saturated pentane solution to −40 °C. Unfortunately, the crystal structure suffers from severe disorder. Each tungsten
  • internal or terminal alkynes to isolate the corresponding alkylidyne complex. In an NMR study on the cleavage of the Mo≡Mo triple bond, in which Mo2F6 was treated with two equivalents of 1-phenyl-1-propyne, no signals corresponding to a possible molybdenum alkylidyne complex were detected in the 1H and 19F
  • -like reaction, the W≡W bond is cleaved, with 2-butyne forming as a side product. Following this reaction by 1H and 19F NMR spectroscopy revealed fast and selective formation of WPhF3, and after 14 minutes, most of the starting material W2F3 was already consumed, with full conversion observed after 28
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Published 18 Sep 2018

Practical tetrafluoroethylene fragment installation through a coupling reaction of (1,1,2,2-tetrafluorobut-3-en-1-yl)zinc bromide with various electrophiles

  • Ken Tamamoto,
  • Shigeyuki Yamada and
  • Tsutomu Konno

Beilstein J. Org. Chem. 2018, 14, 2375–2383, doi:10.3762/bjoc.14.213

Graphical Abstract
  • 1.5 years in the refrigerator [35]. In order to examine the stability of 2-Zn in more detail, we quantitatively evaluated the thermal stability of 2-Zn under various temperature conditions (Figure 2). After a given duration, the recovery yield of 2-Zn was determined by 19F NMR analysis using an
  • for Cu(I)-catalyzed cross-coupling reaction of 2-Zn with benzoyl chloride (5a). Supporting Information Supporting Information File 332: Experimental procedures, characterization data (1H, 13C, 19F NMR, IR and HRMS), copies of 1H, 13C and 19F NMR spectra.
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Published 11 Sep 2018

Determining the predominant tautomeric structure of iodine-based group-transfer reagents by 17O NMR spectroscopy

  • Nico Santschi,
  • Cody Ross Pitts,
  • Benson J. Jelier and
  • René Verel

Beilstein J. Org. Chem. 2018, 14, 2289–2294, doi:10.3762/bjoc.14.203

Graphical Abstract
  • HCl compound 4a afforded an isolable iodonium-type structure [20]. Although this activation can be conveniently followed by 19F NMR spectroscopy with 4a resonating at −40.1 ppm and the fully protonated “iodonium” congener 4c at −20 ppm [1], this technique provides no indication on how to best
  • then subjected to spectroscopic analysis. A 19F NMR chemical shift of −23.2 ppm was obtained, thereby confirming the presence of 4c. However, under these strongly acidic and activating conditions, the compound is unstable over a prolonged period of time (12 h). During the acquisition of the 17O NMR
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Published 30 Aug 2018
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