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Search for "19F NMR" in Full Text gives 266 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Diazirine-functionalized mannosides for photoaffinity labeling: trouble with FimH

  • Femke Beiroth,
  • Tomas Koudelka,
  • Thorsten Overath,
  • Stefan D. Knight,
  • Andreas Tholey and
  • Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2018, 14, 1890–1900, doi:10.3762/bjoc.14.163

Graphical Abstract
  • . This can be monitored by 19F NMR spectroscopy showing the typical diazirine CF3 signal around −68 ppm [29]. Whereas mannoside 3 was received in good purity, compound 4 was always obtained with contaminations. Thus, 3 was the preferred ligand for the following photolabeling experiments. Results obtained
  • the peptides in a 1:1 ratio. After irradiation with UV light, two new signals were detected in nano-LC–ESIMS experiments in comparison to the original peptide spectra (Table 2). It should be noted that whereas we could monitor photodecomposition of the photolabels by 19F NMR spectroscopy (cf. [29
  • ]), we could not observe labeled products by fluorine NMR. This is presumably due to the low labeling efficiency as in the literature 19F NMR spectra were obtained with proteins having 19F-labeled amino acids incorporated [30]. Disappointingly, instead of crosslinking, we observed two different other
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Published 24 Jul 2018

Recent advances in hypervalent iodine(III)-catalyzed functionalization of alkenes

  • Xiang Li,
  • Pinhong Chen and
  • Guosheng Liu

Beilstein J. Org. Chem. 2018, 14, 1813–1825, doi:10.3762/bjoc.14.154

Graphical Abstract
  • ratio of amines and HF was important for obtaining reasonable yields. Indeed, excellent 19F NMR yields albeit lower isolated yields were obtained in this reaction (Scheme 12). In an attempt to induce enantioselectivity, the chiral aryl iodide derivative 39 only gave a moderate enantioselectivity (22% ee
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Published 18 Jul 2018

Synthesis of trifluoromethylated 2H-azirines through Togni reagent-mediated trifluoromethylation followed by PhIO-mediated azirination

  • Jiyun Sun,
  • Xiaohua Zhen,
  • Huaibin Ge,
  • Guangtao Zhang,
  • Xuechan An and
  • Yunfei Du

Beilstein J. Org. Chem. 2018, 14, 1452–1458, doi:10.3762/bjoc.14.123

Graphical Abstract
  • product based on the analysis of its 19F NMR (δ −55.67). The above results from the experiment provided supportive evidence that the CF3 radical was likely involved as a reactive species in the reaction process. Based on this and previous reports [62][63][64][65][66][67][68], a possible reaction pathway
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Published 15 Jun 2018

Hypervalent iodine(III)-mediated decarboxylative acetoxylation at tertiary and benzylic carbon centers

  • Kensuke Kiyokawa,
  • Daichi Okumatsu and
  • Satoshi Minakata

Beilstein J. Org. Chem. 2018, 14, 1046–1050, doi:10.3762/bjoc.14.92

Graphical Abstract
  • solvents and reaction parameters on the decarboxylative acetoxylation.a Supporting Information Supporting Information File 166: Experimental procedures, characterization data, copies of the 1H, 13C, and 19F NMR spectra. Acknowledgements This work was supported by JSPS KAKENHI Grant Number JP16K17868.
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Published 15 May 2018

Imide arylation with aryl(TMP)iodonium tosylates

  • Souradeep Basu,
  • Alexander H. Sandtorv and
  • David R. Stuart

Beilstein J. Org. Chem. 2018, 14, 1034–1038, doi:10.3762/bjoc.14.90

Graphical Abstract
  • nucleophilicity. Supporting Information Supporting Information File 150: General experimental details, procedures, tabulated spectroscopic data, and 1H, 13C{1H}, and 19F NMR spectra of compounds 1g, 2a–i, and 3. Acknowledgements We acknowledge Portland State University for financial support of this research.
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Published 11 May 2018

Fluorocyclisation via I(I)/I(III) catalysis: a concise route to fluorinated oxazolines

  • Felix Scheidt,
  • Christian Thiehoff,
  • Gülay Yilmaz,
  • Stephanie Meyer,
  • Constantin G. Daniliuc,
  • Gerald Kehr and
  • Ryan Gilmour

Beilstein J. Org. Chem. 2018, 14, 1021–1027, doi:10.3762/bjoc.14.88

Graphical Abstract
  • the cyclisation event, oxazoline 2r was generated from the corresponding α-chiral amide under standard conditions. Analysis of the crude reaction mixture by 19F NMR allowed a yield of >95% to be determined and a 1:1 dr. This is to be expected given the remote nature of the stereocentre. It is
  • increased to 32 hours. Yields refer to isolated values whilst NMR yields are given in parentheses (19F NMR using ethyl fluoroacetate as an internal standard). X-ray molecular structure of compound 2c. Thermal ellipsoids shown at the 50% propability level. Torsion angle (F1–C10–C9–O1 −73.4°) consistent with
  • the fluorine gauche effect. CCDC number 1815371. Exploring diastereocontrol and the synthesis of the fluorohydrin 3. Yields in parentheses were determined by 19F NMR using ethyl fluoroacetate as an internal standard. Unless otherwise stated, yields refer to isolated values. Optimisation of reaction
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Published 09 May 2018

Copper-catalyzed asymmetric methylation of fluoroalkylated pyruvates with dimethylzinc

  • Kohsuke Aikawa,
  • Kohei Yabuuchi,
  • Kota Torii and
  • Koichi Mikami

Beilstein J. Org. Chem. 2018, 14, 576–582, doi:10.3762/bjoc.14.44

Graphical Abstract
  • organic layer was dried over anhydrous Na2SO4 and evaporated under reduced pressure (350 mmHg). The concentrated solution was used without purification for the next protection reaction. The yield of alcohol product 2 was determined by 19F NMR analysis using benzotrifluoride (BTF) as an internal standard
  • determined by 19F NMR analysis. p-Nitrobenzoylated alcohol 2a’ was purified by silica-gel column chromatography (EtOAc/hexane 1:40) as a colorless liquid (53% yield for 2 steps, 89% ee). 1H NMR (300 MHz, CDCl3) δ 8.34–8.31 (m, 2H), 8.24–8.20 (m, 2H), 4.33 (q, 4H, J = 6.9 Hz), 1.97 (d, 3H, J = 0.9 Hz), 1.28
  • (t, 3H, J = 7.0 Hz); 13C NMR (75 MHz, CDCl3) δ 164.3, 162.3, 151.1, 134.0, 131.2, 123.7, 122.7 (q, J C-F = 282.9 Hz), 80.7 (q, J C-F = 30.4 Hz), 63.2, 16.6, 13.8; 19F NMR (282 MHz, CDCl3) δ −78.4 (s, 3F); HRMS (APCI-TOF): [M]−· calcd for C13H12F3NO6, 335.0617; found, 335.0623; FTIR (neat, cm−1) 784
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Published 07 Mar 2018

Synthesis and stability of strongly acidic benzamide derivatives

  • Frederik Diness,
  • Niels J. Bjerrum and
  • Mikael Begtrup

Beilstein J. Org. Chem. 2018, 14, 523–530, doi:10.3762/bjoc.14.38

Graphical Abstract
  • 152–154 °C; 1H NMR (500 MHz, methanol-d4) δ 7.99 (dd, J = 9.0, 5.2 Hz, 2H), 7.29 (t, J = 8.8 Hz, 2H); 13C NMR (126 MHz, methanol-d4) δ 167.6 (d, J = 254.3 Hz), 166.0, 132.8 (d, J = 9.6 Hz), 129.1 (d, J = 3.1 Hz), 121.0 (q, J = 321.5 Hz), 117.1 (d, J = 22.7 Hz); 19F NMR (470 MHz, methanol-d4) δ −76.93
  • 8.09 (d, J = 8.0 Hz, 1H), 7.86 (d, J = 8.1 Hz, 1H); 13C NMR (126 MHz, methanol-d4) δ 166.3, 136.5, 136.0 (q, J = 32.6 Hz), 130.6, 127.0 (q, J = 4.0 Hz), 125.0 (q, J = 271.9 Hz), 121.0 (q, J = 321.5 Hz); 19F NMR (470 MHz, methanol-d4) δ −64.31 (s, 3F), −77.06 (s, 3F); HRMS (TOF) m/z: [M − H]− calcd for
  • ), 139.1 (dm, J = 250.0 Hz), 121.0 (q, J = 321.4 Hz), 111.9 (t, J = 17.6 Hz); 19F NMR (470 MHz, methanol-d4) δ −78.15 (s, 3F), −142.78 (d, J = 17.9 Hz, 2F), −152.25 (t, J = 19.2 Hz, 1F), −162.65 (t, J = 18.3 Hz, 2F); HRMS (TOF) m/z: [M − H]− calcd for C8F8NO3S−, 341.9477; found, 341.9520. 4-Bromo-N
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Published 27 Feb 2018

The selective electrochemical fluorination of S-alkyl benzothioate and its derivatives

  • Shunsuke Kuribayashi,
  • Tomoyuki Kurioka,
  • Shinsuke Inagi,
  • Ho-Jung Lu,
  • Biing-Jiun Uang and
  • Toshio Fuchigami

Beilstein J. Org. Chem. 2018, 14, 389–396, doi:10.3762/bjoc.14.27

Graphical Abstract
  • -(ω-carboxy)alkyl benzothioates afforded intramolecular cyclization products like lactones instead of the corresponding α-fluorinated products. Experimental General information 1H, 13C and 19F NMR spectra were recorded on a JEOL JNM EX-270 (1H: 270 MHz, 13C: 67.8 MHz, 19F: 254.05 MHz) spectrometer in
  • CDCl3. The chemical shifts for 1H, 13C and 19F NMR spectra are given in δ (ppm) from internal TMS, CDCl3 and monofluorobenzene, respectively. Cyclic voltammetry was performed using an ALS Instrument model 600A. Preparative electrolysis experiments were carried out with Metronnix Corp. (Tokyo) constant
  • /EtOAc (20:1 to 1:1) as an eluent. The yield of the fluorinated products were estimated by 19F NMR using monofluorobenzene as an internal standard. The known fluorinated products, benzoyl fluoride [39], p-chlorobenzoyl fluoride [40] and p-fluorobenzoyl fluoride [41] were identified by comparison with 19F
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Published 12 Feb 2018

Syn-selective silicon Mukaiyama-type aldol reactions of (pentafluoro-λ6-sulfanyl)acetic acid esters with aldehydes

  • Anna-Lena Dreier,
  • Andrej V. Matsnev,
  • Joseph S. Thrasher and
  • Günter Haufe

Beilstein J. Org. Chem. 2018, 14, 373–380, doi:10.3762/bjoc.14.25

Graphical Abstract
  • addition of ice-water. After work-up 22% of the aldol addition products were formed in a syn/anti-ratio of 97:3 as determined by 19F NMR spectroscopy (Scheme 1). Subsequently, the reaction conditions were optimized (Table 1). Elevation of the reaction temperature (15 h reflux) led to an increase of the
  • , entry 13), while 2-bromo-, 2,6-dichloro- and 2,4-dinitrobenzaldehydes failed to give any aldol products (Table 2, entries 14–16). Besides the starting materials, only minor amounts of SF5-containing side products of unknown structure were detected in the 19F NMR spectra of the crude product mixtures
  • mixture was heated to 40 °C in a sealed tube overnight and directly investigated by 1H and 19F NMR spectroscopy showing the formation of product 4h. Thus, a concerted mechanism seems to be responsible for the exclusive formation of the (E)-configured products. Finally, we attempted to incorporate SF5
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Published 08 Feb 2018

Synthesis of fluoro-functionalized diaryl-λ3-iodonium salts and their cytotoxicity against human lymphoma U937 cells

  • Prajwalita Das,
  • Etsuko Tokunaga,
  • Hidehiko Akiyama,
  • Hiroki Doi,
  • Norimichi Saito and
  • Norio Shibata

Beilstein J. Org. Chem. 2018, 14, 364–372, doi:10.3762/bjoc.14.24

Graphical Abstract
  • neutral size 63–210 μm). The 1H NMR (300 MHz), 19F NMR (282 MHz), and 13C NMR (125 MHz) spectra for solution in CDCl3 or (CD3)2CO were recorded on Varian Mercury 300 and Bruker Avance 500 spectrometers. Chemical shifts (δ) are expressed in ppm downfield from TMS (δ = 0.00) or C6F6 [δ = −162.2 (CDCl3) or
  • . HRMS (EI–TOF) m/z [M]+: calcd for C6H4F5SI, 329.8999; found, 329.9010; 1H NMR (CDCl3, 300 MHz) δ 7.11 (t, J = 9 Hz, 1H), 7.41–7.47 (m, 1H), 7.80 (dd, J = 9 Hz, 3 Hz, 1H), 8.14 (d, J = 9 Hz, 1H); 19F NMR (CDCl3, 282 MHz) δ 63.55 (d, J = 155.1 Hz, 4F), 83.56 (q, J = 155.1 Hz, 1F); 13C{1H}NMR (CDCl3, 126
  • Hz, 1H); 19F NMR ((CD3)2CO), 282 MHz) δ = –79.88 (s, 3F), 64.09 (d, J = 149.5 Hz, 4F), 81.34 (q, J = 149.5 Hz, 1F); 13C{1H}NMR ((CD3)2CO), 126 MHz) δ 21.2, 27.1, 106.6, 121.9 (q, J = 318.8 Hz), 123.0, 131.8, 132.5 (t, J = 5 Hz), 133.7, 135.4, 136.9, 144.5, 147.0, 154.1–154.7 (m). (2-(Pentafluoro-λ6
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Published 07 Feb 2018

Diels–Alder cycloadditions of N-arylpyrroles via aryne intermediates using diaryliodonium salts

  • Huangguan Chen,
  • Jianwei Han and
  • Limin Wang

Beilstein J. Org. Chem. 2018, 14, 354–363, doi:10.3762/bjoc.14.23

Graphical Abstract
  • 2.a Scope of N-substituted pyrroles 1.a Supporting Information Supporting Information File 6: Experimental procedures and characterization data of all products, copies of 1H, 13C, 19F NMR and HRMS spectra of all compounds. Acknowledgements The work was supported by the National Nature Science
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Published 06 Feb 2018

5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines

  • Ranjana Aggarwal and
  • Suresh Kumar

Beilstein J. Org. Chem. 2018, 14, 203–242, doi:10.3762/bjoc.14.15

Graphical Abstract
  • have been confirmed unambiguously by HMBC, HMQC and 19F NMR studies. The authors proposed that trifluoromethyl-β-diketone exists mainly in keto form 17 under solvent-free conditions whereas under solvent-mediated conditions the enolic form 21 towards the carbonyl carbon that carries the CF3 group is
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Published 25 Jan 2018

Nucleophilic fluoroalkylation/cyclization route to fluorinated phthalides

  • Masanori Inaba,
  • Tatsuya Sakai,
  • Shun Shinada,
  • Tsuyuka Sugiishi,
  • Yuta Nishina,
  • Norio Shibata and
  • Hideki Amii

Beilstein J. Org. Chem. 2018, 14, 182–186, doi:10.3762/bjoc.14.12

Graphical Abstract
  • methods, synthetic procedures, 1H and 19F NMR spectra for known compound 1a and full characterization of all new compounds. Acknowledgements This article is dedicated to the memory of Professor Yoshihiko Ito (1937-2006) on the occasion of the 10th anniversary of his sudden death. The financial support of
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Published 19 Jan 2018

Progress in copper-catalyzed trifluoromethylation

  • Guan-bao Li,
  • Chao Zhang,
  • Chun Song and
  • Yu-dao Ma

Beilstein J. Org. Chem. 2018, 14, 155–181, doi:10.3762/bjoc.14.11

Graphical Abstract
  • Cu catalysis. Trifluoromethylation of arylboronic acids reported by Sanford’s group. Isolated yield. aYields determined by 19F NMR analysis. Trifluoromethylation of arylboronic acids and vinylboronic acids reported by the group of Beller. Yields determined by 19F NMR analysis. aGC yield. bIsolated
  • employed as the substrates, Xiao and co-workers [15] firstly used S-(trifluoromethyl)diphenylsulfonium salts in the presence of copper powder to convert the substrates into the corresponding trifluoromethylated compounds in high yield. The CuCF3 intermediate was formed in this process, as confirmed by 19F
  • NMR spectroscopy and ESIMS. It was proposed that [CuCF3] was generated through reduction of S-(trifluoromethyl)diphenylsulfonium triflate by Cu0 through a single-electron transfer (SET) process (Scheme 3). In 2015, the group of Lu and Shen [16] developed a new electrophilic trifluoromethylation
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Published 17 Jan 2018

Gram-scale preparation of negative-type liquid crystals with a CF2CF2-carbocycle unit via an improved short-step synthetic protocol

  • Tatsuya Kumon,
  • Shohei Hashishita,
  • Takumi Kida,
  • Shigeyuki Yamada,
  • Takashi Ishihara and
  • Tsutomu Konno

Beilstein J. Org. Chem. 2018, 14, 148–154, doi:10.3762/bjoc.14.10

Graphical Abstract
  • products. Yields of all reaction steps in Scheme 2. Melting points of various 1,4-disubstituted cyclohexane-1,4-diol derivatives. Supporting Information Supporting Information File 10: Experimental procedures, characterization data, and copies of 1H, 13C and 19F NMR spectra.
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Published 15 Jan 2018

The synthesis of the 2,3-difluorobutan-1,4-diol diastereomers

  • Robert Szpera,
  • Nadia Kovalenko,
  • Kalaiselvi Natarajan,
  • Nina Paillard and
  • Bruno Linclau

Beilstein J. Org. Chem. 2017, 13, 2883–2887, doi:10.3762/bjoc.13.280

Graphical Abstract
  • resulted in 56% yield after column chromatography. 19F NMR analysis of the crude product showed a dr of 98:2 in favour of (±)-syn-4. However, given a diastereomerically pure starting material was used, this indicates that SN1 or neighbouring group participation pathways may have occurred, although only to
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Published 27 Dec 2017

The use of 4,4,4-trifluorothreonine to stabilize extended peptide structures and mimic β-strands

  • Yaochun Xu,
  • Isabelle Correia,
  • Tap Ha-Duong,
  • Nadjib Kihal,
  • Jean-Louis Soulier,
  • Julia Kaffy,
  • Benoît Crousse,
  • Olivier Lequin and
  • Sandrine Ongeri

Beilstein J. Org. Chem. 2017, 13, 2842–2853, doi:10.3762/bjoc.13.276

Graphical Abstract
  • activity [3][4]. Fluorinated amino acids can also be used as powerful 19F NMR probes for the study of protein–ligand interactions and enzymatic activities [5][6][7][8]. However, the development of fluorinated peptides as drug candidates seems to be largely under-exploited. Investigation on the influence of
  • straightforward methodology and we have adapted Zeng’s synthesis starting from the (R)-Garner’s aldehyde. (2S,3R)-Boc-CF3-Thr(Bzl) was obtained with satisfactory yields (Scheme 1). In this synthetic pathway, the key intermediate 6 was obtained, as a mixture of two diastereoisomers (9:1, evaluated by 19F NMR) via
  • release of free (2S,3S)-CF3-threonine whose diastereoselectivity was determined to be about 96% by 19F NMR. Although in most of the reported cases, the free amino acid was released into the aqueous phase, and then purified by ion-exchange chromatography, we purified the free (2S,3S)-CF3-threonine by
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Published 21 Dec 2017

CF3SO2X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF3SO2Na

  • Hélène Guyon,
  • Hélène Chachignon and
  • Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

Graphical Abstract
  • allowing access to various β-trifluoromethyl ketones 24 featuring aryl, alkyl, functionalised alkyl, alkenyl, acetal, silylated alcohol, pyran, and piperidine functionalities (R group in 24). Mechanistic studies by 19F NMR allowed to identify CF3 complexes of copper(I) and copper(III) and the predominance
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Published 19 Dec 2017

Development of a fluorogenic small substrate for dipeptidyl peptidase-4

  • Futa Ogawa,
  • Masanori Takeda,
  • Kanae Miyanaga,
  • Keita Tani,
  • Ryuji Yamazawa,
  • Kiyoshi Ito,
  • Atsushi Tarui,
  • Kazuyuki Sato and
  • Masaaki Omote

Beilstein J. Org. Chem. 2017, 13, 2690–2697, doi:10.3762/bjoc.13.267

Graphical Abstract
  • (4 Å). All commercially available materials were used as received without further purification. 1H NMR, 13C NMR and 19F NMR spectra were measured on a JEOL ECZS 400S spectrometer (1H: 400MHz, 13C: 100 MHz, 19F: 376 MHz). Chemical shifts of 1H NMR and 13C NMR are reported in parts per million from
  • tetramethylsilane (TMS), used as an internal standard at 0 ppm. Chemical shifts of 19F NMR are reported in parts per million from trichlorofluoromethane (CFCl3), used as an internal standard at 0 ppm. All dates are reported as follows: chemical shifts, relative integration value, multiplicity (s = singlet, d
  • = 2.1, 15.8 Hz, 1H), 7.30 (dd, J = 1.8, 8.2 Hz, 1H), 7.36 (d, J = 1.8 Hz, 1H); 13C NMR (CDCl3) δ 112.9 (q, J = 33.7 Hz), 116.8, 117.9 (q, J = 33.7 Hz), 119.2, 123.3 (q, J = 269.4 Hz), 123.9 (q, J = 269.4 Hz), 124.4, 127.9, 132.7 (q, J = 6.7 Hz), 136.8 (q, J = 6.7 Hz), 146.3; 19F NMR (CDCl3) δ 89.84 (dd
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Published 14 Dec 2017

Ring-size-selective construction of fluorine-containing carbocycles via intramolecular iodoarylation of 1,1-difluoro-1-alkenes

  • Takeshi Fujita,
  • Ryo Kinoshita,
  • Tsuyoshi Takanohashi,
  • Naoto Suzuki and
  • Junji Ichikawa

Beilstein J. Org. Chem. 2017, 13, 2682–2689, doi:10.3762/bjoc.13.266

Graphical Abstract
  • . Experimental General: 1H NMR, 13C NMR, and 19F NMR spectra were recorded on a Bruker Avance 500 or a JEOL ECS-400 spectrometer. Chemical shift values are given in ppm relative to internal Me4Si (for 1H NMR: δ = 0.00 ppm), CDCl3 (for 13C NMR: δ = 77.0 ppm), C6F6 (for 19F NMR: δ = 0.0 ppm), and (4-MeC6H4)2C(CF3
  • )2 (for 19F NMR: δ = 97.9 ppm). IR spectra were recorded on a Horiba FT-300S spectrometer using the attenuated total reflectance (ATR) method. Mass spectra were measured on a JEOL JMS-T100GCV spectrometer. X-ray diffraction studies were performed on a Bruker APEXII ULTRA instrument equipped with a
  • , 134.6, 136.8; 19F NMR (470 MHz, CDCl3) δ 124.7 (br s); IR (neat): 3068, 1489, 1454, 1126, 1147, 1097, 964, 850, 742, 696, 592 cm−1; HRMS–EI (m/z): [M]+ calcd for C21H15F2I, 432.0186; found: 432.0166. Typical procedure for the iodoarylation of 2-(3,3-difluoroallyl)biaryls 5: To a HFIP (2.5 mL) and
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Published 14 Dec 2017

Electrophilic trifluoromethylselenolation of terminal alkynes with Se-(trifluoromethyl) 4-methylbenzenesulfonoselenoate

  • Clément Ghiazza,
  • Anis Tlili and
  • Thierry Billard

Beilstein J. Org. Chem. 2017, 13, 2626–2630, doi:10.3762/bjoc.13.260

Graphical Abstract
  • reaction was stirred at 25 °C for 15–18 hours (conversion was checked by 19F NMR with PhOCF3 as internal standard). The crude residue was purified by chromatography to afford the desired products 3–5. Single-crystal X-ray structure of 3a. Electrophilic addition of 1a to alkynes. Yields shown are those of
  • isolated products; yields determined by 19F NMR spectroscopy with PhOCF3 as an internal standard are shown in parentheses. Mechanism proposal. Perfluoroalkylselenolation of alkynes. Yields shown are those of isolated products; yields determined by 19F NMR spectroscopy with PhOCF3 as an internal standard
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Published 07 Dec 2017

Regioselective decarboxylative addition of malonic acid and its mono(thio)esters to 4-trifluoromethylpyrimidin-2(1H)-ones

  • Sergii V. Melnykov,
  • Andrii S. Pataman,
  • Yurii V. Dmytriv,
  • Svitlana V. Shishkina,
  • Mykhailo V. Vovk and
  • Volodymyr A. Sukach

Beilstein J. Org. Chem. 2017, 13, 2617–2625, doi:10.3762/bjoc.13.259

Graphical Abstract
  • Michael-type regioisomer 5a (Table 1, entry 1). The reaction course and the ratio of the regioisomers formed were conveniently monitored by 19F NMR spectroscopy. Acid 4a precipitated in pure form on evaporating toluene and treating the residue with diluted hydrochloric acid. Performing the reaction in a
  • reaction in toluene in the presence of TEA (1 equiv) at 80 °C for 4 hours gave the best result in terms of regioselectivity and yield of 6a (Table 3, entry 1), virtually the only product formed in all the solvents used here (as evidenced by 19F NMR monitoring). The addition of malonic acid monophenyl ester
  • : Copies of the 1H, 13C, and 19F NMR spectra.
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Published 07 Dec 2017

A concise flow synthesis of indole-3-carboxylic ester and its derivatisation to an auxin mimic

  • Marcus Baumann,
  • Ian R. Baxendale and
  • Fabien Deplante

Beilstein J. Org. Chem. 2017, 13, 2549–2560, doi:10.3762/bjoc.13.251

Graphical Abstract
  • = triplet, q = quartet, p = pentet, m = multiplet, br. s = broad singlet, app = apparent. Data for 13C NMR are reported in terms of chemical shift (δ ppm) and multiplicity (C, CH, CH2 or CH3). Data for 19F NMR were recorded on the above instruments at a frequency of 376 MHz using CFCl3 as external standard
  • 162.8 (C), 147.6 (C), 133.3 (q, J = 35 Hz, C), 132.4 (CH), 131.0 (q, J = 4 Hz, CH), 128.9 (C), 123.7 (q, J = 4 Hz, CH), 122.2 (q, J = 273 Hz, C), 113.8 (C), 64.4 (CH2), 41.2 (CH), 13.9 (CH3); 19F NMR (376 MHz, CDCl3) δ −63.2; IR (neat) ν/cm−1: 3092 (w), 2925 (w), 1732 (m), 1537 (m), 1502 (m), 1357 (m
  • 164.4 (C), 135.8 (d, J = 3 Hz, CH), 128.7 (C), 125.4 (q, J = 273 Hz, C), 123.3 (q, J = 34 Hz, C), 121.75 (CH), 118.0 (q, J = 4 Hz, CH), 117.6 (C), 110.3 (q, J = 4 Hz, CH), 107.5 (C), 59.8 (CH2), 14.9 (CH3); 19F NMR (376 MHz, DMSO-d6) δ −59.3; IR (neat) ν/cm−1: 3196 (m), 1667 (s), 1514 (m), 1440 (m
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Published 29 Nov 2017

One-pot three-component route for the synthesis of S-trifluoromethyl dithiocarbamates using Togni’s reagent

  • Azim Ziyaei Halimehjani,
  • Martin Dračínský and
  • Petr Beier

Beilstein J. Org. Chem. 2017, 13, 2502–2508, doi:10.3762/bjoc.13.247

Graphical Abstract
  • using IR, 1H NMR, 13C NMR, 19F NMR and HRMS analysis. The dithiocarbamate moiety in S-trifluoromethyl dithiocarbamates appeared at 180–185 ppm in the 13C NMR spectra, while this group usually can be found at 190–200 ppm for S-alkyl dithiocarbamates [4][5][6][7][8][9][10][11][12]. Also the carbon of the
  • CF3 group was observed at around 128 ppm as quartet with a coupling constant of ≈308 Hz. In addition, a singlet at −40 ppm in the 19F NMR spectra was assigned to the CF3 group. The one-pot reaction of benzylamine with CS2 and Togni's reagent I under optimal reaction conditions was also investigated
  • , and 19F NMR spectra of all compounds. Acknowledgements We are grateful to the faculty of chemistry of Kharazmi University for supporting this work. This work was also supported by the Academy of Sciences of the Czech Republic (Research Plan RVO: 61388963) and Ministry of Education of the Czech
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Published 24 Nov 2017
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