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Search for "19F)" in Full Text gives 272 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Synthesis of 2,2-difluoro-1,3-diketone and 2,2-difluoro-1,3-ketoester derivatives using fluorine gas

  • Alexander S. Hampton,
  • David R. W. Hodgson,
  • Graham McDougald,
  • Linhua Wang and
  • Graham Sandford

Beilstein J. Org. Chem. 2024, 20, 460–469, doi:10.3762/bjoc.20.41

Graphical Abstract
  • reaction of compound 1a with Selectfluor in acetonitrile (MeCN) gave high yields of the monofluorinated product 2a with no difluorinated product being observed by 19F NMR analysis of the product mixture after 5 h (Scheme 1). In contrast, attempts to fluorinate 1a with one equivalent of fluorine gas in MeCN
  • gave no noticeable conversion on analysis by 19F NMR spectroscopy, and a large excess of fluorine led to formation of a dark brown tar from which no useful product could be isolated. On the bases of these failed attempts, coupled with our previous experiences with the DBM scaffold [16][17][36], we used
  • the crude yields of fluorinated products were estimated by 19F NMR integration (monofluoro product 2a, δF −189.9 ppm; difluoro product 3a, δF −102.7 ppm) (Table 1, entry 3). Using excess fluorine or DABCO (entries 5 and 6 in Table 1) led to the formation of tars, while 0.1 equiv of DABCO (entry 7
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Published 28 Feb 2024

(E,Z)-1,1,1,4,4,4-Hexafluorobut-2-enes: hydrofluoroolefins halogenation/dehydrohalogenation cascade to reach new fluorinated allene

  • Nataliia V. Kirij,
  • Andrey A. Filatov,
  • Yurii L. Yagupolskii,
  • Sheng Peng and
  • Lee Sprague

Beilstein J. Org. Chem. 2024, 20, 452–459, doi:10.3762/bjoc.20.40

Graphical Abstract
  • .20.40 Abstract A series of 2,3-dihalo-1,1,1,4,4,4-hexafluorobutanes and 2-halo-1,1,1,4,4,4-hexafluorobut-2-enes were prepared from commercially available hydrofluoroolefins 1,1,1,4,4,4-hexafluorobut-2-enes and their 1H, 19F and 13C chemical shifts measured. Some reactions of synthesized 2-halo
  • of stereoisomers in 2:1 ratio. After isolation by distillation, 2,3-dibromo-1,1,1,4,4,4-hexafluorobutane (2) was characterized by 1H, 19F, 13C NMR and mass spectra. We studied the reaction of dibromoalkane 2 with various bases such as DBU, Hünig’s base (iPr2NEt), and potassium hydroxide (Table 1). In
  • all cases, except the reaction in diglyme (Table 1, entry 5), a mixture of (E)- and (Z)-2-bromo-1,1,1,4,4,4-hexafluorobut-2-enes (3a,b) in a ratio of 2:1 was formed. The configuration of the isomers was determined by the 5JFFcis coupling constant in the 19F{H} NMR spectrum (ca. 0 Hz for (Z)-isomer and
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Published 27 Feb 2024

Mono or double Pd-catalyzed C–H bond functionalization for the annulative π-extension of 1,8-dibromonaphthalene: a one pot access to fluoranthene derivatives

  • Nahed Ketata,
  • Linhao Liu,
  • Ridha Ben Salem and
  • Henri Doucet

Beilstein J. Org. Chem. 2024, 20, 427–435, doi:10.3762/bjoc.20.37

Graphical Abstract
  • from Acros. KOPiv (95%) was purchased from Doug Discovery. These compounds were not purified before use. All reagents were weighed and handled in air. All reactions were carried out under an inert atmosphere with standard Schlenk techniques. 1H, 19F and 13C NMR spectra were recorded on Bruker Avance
  • data of synthesized compounds. Supporting Information File 44: Copies of 1H, 19F, and 13C NMR spectra. Acknowledgements We are grateful to Dr. Elsa Caytan for NMR experiments. Part of this work has been performed using the PRISM core facility (Biogenouest, Univ Rennes, Univ Angers, INRAE, CNRS, FRANCE
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Published 23 Feb 2024

Photochromic derivatives of indigo: historical overview of development, challenges and applications

  • Gökhan Kaplan,
  • Zeynel Seferoğlu and
  • Daria V. Berdnikova

Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23

Graphical Abstract
  • -donating group, 19a) to 6.8 h (in the presence of electron-withdrawing group, 19f) depending on the effect of the substituents in the aryl groups. Further insights into the photoisomerization mechanism of N,N'-diarylindigos were provided in 2022 using steady-state and time-resolved spectroscopy experiments
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Published 07 Feb 2024

Chiral phosphoric acid-catalyzed transfer hydrogenation of 3,3-difluoro-3H-indoles

  • Yumei Wang,
  • Guangzhu Wang,
  • Yanping Zhu and
  • Kaiwu Dong

Beilstein J. Org. Chem. 2024, 20, 205–211, doi:10.3762/bjoc.20.20

Graphical Abstract
  • and the reaction mixture was stirred at room temperature for 3 h. After concentrating the mixture, the residue was purified by column chromatography on silica gel using a mixture of petroleum ether/ethyl acetate 30:1 (v/v) as the eluent to afford products 2. The yields were determined by 19F NMR
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Published 01 Feb 2024

Comparison of glycosyl donors: a supramer approach

  • Anna V. Orlova,
  • Nelly N. Malysheva,
  • Maria V. Panova,
  • Nikita M. Podvalnyy,
  • Michael G. Medvedev and
  • Leonid O. Kononov

Beilstein J. Org. Chem. 2024, 20, 181–192, doi:10.3762/bjoc.20.18

Graphical Abstract
  • after immersion in a 1:10 (v/v) mixture of 85% aq H3PO4 and 95% aq EtOH. 1H, 13C, and 19F NMR spectra of solutions in CDCl3 and acetone-d6 were recorded on a Bruker AVANCE-600 instrument at 600 MHz for 1H and 151 MHz for 13C or on a Bruker AM-300 instrument at 300 MHz for 1H, 75 MHz for 13C, and 282 MHz
  • for 19F NMR. The 1H chemical shifts are given relative to the signal of the residual CHCl3 (δH 7.27) or acetone-d5 (δH 2.05), the 13C chemical shifts were measured relative to the signal of CDCl3 (δC 77.0) or acetone-d6 (δC 29.92). The 19F chemical shifts are given relative to the external signal of
  • (q, JC,F = 285, CF3), 115.2 (q, JC,F = 288, CF3), 127.6, 129.6, 130.6, 136.0 (Ph), 156.4 (q, JC,F = 45, COCF3), 156.9 (q, JC,F = 44, COCF3), 158.0 (q, JC,F = 39, COCF3), 166.2, 167.5, 168.4 (COCH2Cl, CO2Me); 19F NMR (282 MHz, CDCl3, δ, ppm) −76.8 (NHCOCF3), −75.7, −75.2 (OCOCF3); HRESIMS (m/z): [M
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Published 31 Jan 2024

Visible-light-induced radical cascade cyclization: a catalyst-free synthetic approach to trifluoromethylated heterocycles

  • Chuan Yang,
  • Wei Shi,
  • Jian Tian,
  • Lin Guo,
  • Yating Zhao and
  • Wujiong Xia

Beilstein J. Org. Chem. 2024, 20, 118–124, doi:10.3762/bjoc.20.12

Graphical Abstract
  • . The addition of a typical radical scavenger – TEMPO (2,2,6,6-tetramethylpiperidin-1-yloxyl) significantly inhibited the reaction (as shown in Scheme 3), suggesting the involvement of radical species during the reaction process. Moreover, the radical trapping product was detected and confirmed via 19F
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Published 19 Jan 2024

NMRium: Teaching nuclear magnetic resonance spectra interpretation in an online platform

  • Luc Patiny,
  • Hamed Musallam,
  • Alejandro Bolaños,
  • Michaël Zasso,
  • Julien Wist,
  • Metin Karayilan,
  • Eva Ziegler,
  • Johannes C. Liermann and
  • Nils E. Schlörer

Beilstein J. Org. Chem. 2024, 20, 25–31, doi:10.3762/bjoc.20.4

Graphical Abstract
  • quiz material for intermediate to more advanced students. A third group of exercises includes additional experiments e.g., NOESY or 1D NOE spectra and 1D/2D heteronuclear experiments including nuclei such as 15N or 19F [43]. For all three exercise collections, students may draw a derived structure and
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Published 05 Jan 2024

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF3: the case of alkyne hydration. Chemistry vs electrochemistry

  • Marta David,
  • Elisa Galli,
  • Richard C. D. Brown,
  • Marta Feroci,
  • Fabrizio Vetica and
  • Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

Graphical Abstract
  • and anion of the IL as the length of the side alkyl chain increases, which makes the BF4‒/water interaction more effective. Although Saihara and co-workers demonstrated that BF4‒ hydrolysis generates HF, which reacts with the surrounding glass container yielding SiF62‒ (signal at −130 ppm in 19F NMR
  • spectrum) [106], we never detected such a peak in 19F NMR spectra of the neat IL, analysed after reaction work-up, keeping it under vacuum to completely eliminate diethyl ether traces before NMR analysis. It should be mentioned that the solution was kept in the NMR tubes only for the time necessary to
  • -chelate. In fact, the following convincing peaks were found in the NMR spectra: a singlet at 6.11 ppm, along with a quartet at 4.68 ppm (1H NMR spectrum), a peak at 83.3 ppm (13C NMR spectrum) and a singlet at −139.1 ppm (19F NMR spectrum) [109]. A simple washing with distilled water gave the
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Published 28 Dec 2023

Substituent-controlled construction of A4B2-hexaphyrins and A3B-porphyrins: a mechanistic evaluation

  • Seda Cinar,
  • Dilek Isik Tasgin and
  • Canan Unaleroglu

Beilstein J. Org. Chem. 2023, 19, 1832–1840, doi:10.3762/bjoc.19.135

Graphical Abstract
  • -tosylimines. Experimental General method: All reagents and solvents were purchased from Sigma-Aldrich, Fisher Scientific, or Acros Organics and were used without further purification. 1H NMR (400 MHz), 13C NMR (100 MHz), and 19F NMR (376 MHz) spectra were recorded on a Bruker 400, Ultra Shield high
  • -performance digital FT-NMR spectrometer. Data for 1H NMR, 13C NMR, and 19F NMR are reported as follows: chemical shift (δ, ppm), multiplicity (s = singlet, d = doublet, t = triplet, m = multiplet, q= quartet, bs = broad singlet, dd = doublet of doublets, td = triplet of doublets, qd = quartet of doublets
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Published 06 Dec 2023

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

  • Gyula Dargó,
  • Dóra Erdélyi,
  • Balázs Molnár,
  • Péter Kisszékelyi,
  • Zsófia Garádi and
  • József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

Graphical Abstract
  • 22.8, 14.2 ppm; 19F NMR −63.1 ppm; HRESI(+)-MS (m/z): [M + H+] calcd for C94H144F6N5O7, 1569.0970; found, 1569.957. General procedure for the solvent screening of stereoselective Michael addition of acetylacetone to trans-β-nitrostyrene First, trans-β-nitrostyrene (12, 11.9 mg, 0.08 mmol) and the
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Published 24 Nov 2023

Morpholine-mediated defluorinative cycloaddition of gem-difluoroalkenes and organic azides

  • Tzu-Yu Huang,
  • Mario Djugovski,
  • Sweta Adhikari,
  • Destinee L. Manning and
  • Sudeshna Roy

Beilstein J. Org. Chem. 2023, 19, 1545–1554, doi:10.3762/bjoc.19.111

Graphical Abstract
  • 19F NMR spectroscopy to monitor the consumption of the gem-difluoro starting material 1, which was completely consumed within 16 h (Figure 3). However, a 48 h time course gave a superior yield (Table 1, entry 13 vs entry 20). We hypothesize this might be due to the volatile nature of the gem
  • . Additionally, 30% of the aniline byproduct was also isolated, which explains the modest yields of this reaction and the sluggish nature. To investigate the mechanism of the current transformation, we conducted a series of experiments including a time course of the reaction using 19F NMR spectroscopy (Figure 3
  • and beyond. The Z-geometry of INT-1 was determined from its 3JH−F coupling constant of 35.7 Hz in the 1H NMR with a matching J value in the 19F NMR. This is in agreement with Cao’s report on the geometry of N-(α-fluorovinyl)azoles [33]. The configurations of the E- and Z-isomers were determined by
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Published 05 Oct 2023

Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid

  • Vladislav A. Sokolov,
  • Andrei A. Golushko,
  • Irina A. Boyarskaya and
  • Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2023, 19, 1460–1470, doi:10.3762/bjoc.19.105

Graphical Abstract
  • of enones 2a,e,n with an excess (5 equiv) of AlBr3 or AlCl3 in CH2Cl2 solution at room temperature for 3 days afforded complex mixtures of compounds. Then, the protonation of compounds 1 and 2 in TfOH was investigated by means of NMR spectroscopy. According to the 1H, 13C, and 19F NMR data, hydroxy
  • -protonated forms B is substantially delocalized from the carbonyl group to vinyl carbon C3. For fluorophenyl-substituted compounds and cations 1d and Ad, 2d and Bd, also a large downfield shift of the corresponding fluorine signals is observed in the 19F NMR spectra (∆δ = 25.3–25.7 ppm), which shows a
  • ketones 1a,c,f,i into the corresponding enones 2 and indanones 3 in TfOH at 80 °C for shorter reaction time under the conditions of incomplete conversion of the starting compounds.a 1H, 13C, and 19F NMR data of compounds 1, and 2 in CDCl3 and their O-protonated forms A, and B, respectively, in TfOH
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Published 27 Sep 2023

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

  • Nosheen Beig,
  • Varsha Goyal and
  • Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

Graphical Abstract
  • NEt3·3HF, AgHF2 could also be used. The complexes were found to be air-stable in the solid state and moderately stable in solution. They were unambiguously characterized on the basis of NMR studies including 19F NMR and X-ray crystal analysis. With the IMes ligand, an air-stable bis(NHC)Cu(I) complex
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Published 20 Sep 2023

Radical ligand transfer: a general strategy for radical functionalization

  • David T. Nemoto Jr,
  • Kang-Jie Bian,
  • Shih-Chieh Kao and
  • Julian G. West

Beilstein J. Org. Chem. 2023, 19, 1225–1233, doi:10.3762/bjoc.19.90

Graphical Abstract
  • . To close the cycle and reform the oxo ligand on the Mn(V) species, a stoichiometric amount of iodosylbenzene is used in the reaction. While initial development of this reaction focused on incorporating the stable 19F, subsequent study expanded the scope to RLT of the unstable 18F radioisotope, an
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Published 15 Aug 2023

Direct C2–H alkylation of indoles driven by the photochemical activity of halogen-bonded complexes

  • Martina Mamone,
  • Giuseppe Gentile,
  • Jacopo Dosso,
  • Maurizio Prato and
  • Giacomo Filippini

Beilstein J. Org. Chem. 2023, 19, 575–581, doi:10.3762/bjoc.19.42

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  • found to shift to lower ppm values because the Hα nuclei have been affected by higher electron density caused by the formation of the halogen-bonded complex between 2a and DABCO. To confirm that the shift of Hα was indeed produced by a halogen-bonding interaction, 19F NMR analysis of compound 2d, which
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Published 27 Apr 2023

Access to cyclopropanes with geminal trifluoromethyl and difluoromethylphosphonate groups

  • Ita Hajdin,
  • Romana Pajkert,
  • Mira Keßler,
  • Jianlin Han,
  • Haibo Mei and
  • Gerd-Volker Röschenthaler

Beilstein J. Org. Chem. 2023, 19, 541–549, doi:10.3762/bjoc.19.39

Graphical Abstract
  • stereochemistry of the main isomer, the 19F,1H-HOESY NMR spectrum of compound 6c was recorded. The spectrum shows direct correlation of one fluorine nucleus of the difluoromethyl phosphonate group with two cyclopropane protons at 1.75 and 2.91 ppm, respectively. Thus, it is conceivable that the major
  • Pr2 and Pr4 (ΔG = −42.5 and −43.3 kcal·mol−1; cis-6c), respectively. This is consistent with the experimental results, since two sets of signals corresponding to the diastereoisomers trans-6c and cis-6c are always observed in the 19F NMR spectrum of the crude mixture, with a slight preference for the
  • slight preference for one diastereoisomer. The presented results turn of a new page for the future of diazo chemistry. 19F,1H-HOESY spectrum of compound 6c. Previous works (A–D) and the extension (this work). Synthesis of diethyl 2-diazo-1,1,3,3,3-pentafluoropropylphosphonate (5). Scope of the
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Published 25 Apr 2023

Dipeptide analogues of fluorinated aminophosphonic acid sodium salts as moderate competitive inhibitors of cathepsin C

  • Karolina Wątroba,
  • Małgorzata Pawełczak and
  • Marcin Kaźmierczak

Beilstein J. Org. Chem. 2023, 19, 434–439, doi:10.3762/bjoc.19.33

Graphical Abstract
  • , obtaining white powders with a yield of 99% in each case. The resulting sodium salts of phosphonic acids 9 and 11 were subjected to 1H, 13C, 19F, and 31P NMR spectroscopic analysis as well as mass spectrometry (MS) confirming their purity. The spectroscopic data of 9 and 11 are in agreement with the
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Published 12 Apr 2023

Catalytic aza-Nazarov cyclization reactions to access α-methylene-γ-lactam heterocycles

  • Bilge Banu Yagci,
  • Selin Ezgi Donmez,
  • Onur Şahin and
  • Yunus Emre Türkmen

Beilstein J. Org. Chem. 2023, 19, 66–77, doi:10.3762/bjoc.19.6

Graphical Abstract
  • 19b–d in good yields (54–69%). We were pleased to see that the CF3-substituted aza-Nazarov product 19e was isolated as single diastereomer in 76% yield along with only 8% of the minor diastereomer. Surprisingly, aza-Nazarov products 19f with a 4-Cl substituent on the phenyl ring as well as 19g and 19h
  • -Nazarov cyclization. X-ray crystal structure of compound 19l. Examples of aza-Nazarov reactions. Aza-Nazarov cyclization on gram scale. Scope of the aza-Nazarov cyclization with acyclic imines. aThe syntheses of aza-Nazarov products 19b, 19c, and 19f were described previously [35]. bThe reaction was
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Published 17 Jan 2023

Simple synthesis of multi-halogenated alkenes from 2-bromo-2-chloro-1,1,1-trifluoroethane (halothane)

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

Beilstein J. Org. Chem. 2022, 18, 1567–1574, doi:10.3762/bjoc.18.167

Graphical Abstract
  • experiments with the aim of identifying further applications of 2 will be reported in due course. 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 reported in ppm from the center line of a triplet at 77.16 ppm for deuteriochloroform. Chemical shifts of 19F NMR are reported in ppm from CFCl3 as an internal standard. All data are reported as follows: chemical shifts, relative integration value, multiplicity (s
  • ), 153.9; 19F NMR (376 MHz, CDCl3) δ −80.5 (s, 1F), −80.6 (s, 1F); EIMS m/z: 250, 252 [M]+; HREIMS: [M]+ calcd for C8H5BrClFO, 249.9196, 251.9176; found, 249.9202, 251.9172. (3-Chloro-4-fluoro-4-phenoxybut-3-en-1-yn-1-yl)trimethylsilane (7): To a solution of 2a (0.5 mmol), bis(triphenylphosphine)palladium
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Published 21 Nov 2022

Heterogeneous metallaphotoredox catalysis in a continuous-flow packed-bed reactor

  • Wei-Hsin Hsu,
  • Susanne Reischauer,
  • Peter H. Seeberger,
  • Bartholomäus Pieber and
  • Dario Cambié

Beilstein J. Org. Chem. 2022, 18, 1123–1130, doi:10.3762/bjoc.18.115

Graphical Abstract
  • enabled straightforward reaction monitoring via 19F NMR. To this end, a 1 T benchtop NMR equipped with a flow cell was connected to the reactor outlet and used to acquire a series of spectra. In particular, a series of 128 repetitions with a 90° pulse width and a relatively long repetition time of 5.2 s
  • outlet. First, we verified that the NMR yield calculated directly from the benchtop 19F NMR spectrum was in good agreement with the high-field NMR yields calculated with an internal standard (see Supporting Information File 1, Table S1). Then, a program was developed to monitor the reaction yield over
  • time by automatically acquiring, processing and integrating the 19F NMR spectrum of the reaction mixture flowing in the spectrometer (see relevant code in Supporting Information File 3). In particular, the python packages flowchem [35] and nmrglue [36] were used to control the spectrometer and process
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Published 29 Aug 2022

Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons

  • Hengjia Liu and
  • Guohua Xie

Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83

Graphical Abstract
  • reaction. In order to clarify the coordination reaction of nitrogen atoms, Bazan’s group designed a conjugated polymer containing pyridine and thiazole groups and small molecule 15 (Figure 8) and compared the 1H NMR spectra and 19F NMR spectra after the addition of 1 equivalent B(C6F5)3 at various
  • temperatures from 230 to 300 K (see Figure 9) [43]. As shown in Figure 9a, when the temperature reached 280 K, the aromatic resonances became intense, implying the appearance of a new species, which was assigned to the Lewis acid–base adduct. Fifteen new resonance peaks were also observed in the 19F NMR
  • small molecule 15 containing pyridine and thiazole groups reported by Bazan et al. and pyridine groups-containing diketopyrrolopyrroles (DPP) 16–18 investigated by Huang et al. (a) 1H NMR spectra in the aromatic region and (b) 19F NMR spectra of compound 15 (top) and the mixture with 1 equivalent B(C6F5
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Published 12 Jul 2022

Direct C–H amination reactions of arenes with N-hydroxyphthalimides catalyzed by cuprous bromide

  • Dongming Zhang,
  • Bin Lv,
  • Pan Gao,
  • Xiaodong Jia and
  • Yu Yuan

Beilstein J. Org. Chem. 2022, 18, 647–652, doi:10.3762/bjoc.18.65

Graphical Abstract
  • . A plausible reaction mechanism. Optimization of the reaction conditions.a Supporting Information Supporting Information File 48: Synthetic schemes for products, characterization data, and copies of 1H, 13C, and 19F NMR spectra. Funding We gratefully acknowledge funding from Jiangsu Provincial
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Published 03 Jun 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
  • NMR). 19F NMR spectra were recorded on a Bruker-400 spectrometer. Coupling constants (J) are given in Hz. The following abbreviations were used to designate the multiplicities: s = singlet, d = doublet, t = triplet, q = quartet, quint = quintet, m = multiplet, br = broad. Melting points were measured
  • copies of 1H, 13C, and 19F NMR spectra. Funding This work was supported by the American Association of Colleges of Pharmacy (2018 New Investigator Award to H. V. L.), the National Institute of General Medical Sciences (P30GM122733 pilot project award to H. V. L.), and funds from the Department of
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Published 22 Apr 2022

Multi-faceted reactivity of N-fluorobenzenesulfonimide (NFSI) under mechanochemical conditions: fluorination, fluorodemethylation, sulfonylation, and amidation reactions

  • José G. Hernández,
  • Karen J. Ardila-Fierro,
  • Dajana Barišić and
  • Hervé Geneste

Beilstein J. Org. Chem. 2022, 18, 182–189, doi:10.3762/bjoc.18.20

Graphical Abstract
  • monofluorinated product 2c in 51% yield. Analysis of the milled mixture by 1H and 19F NMR spectroscopy also revealed the presence of difluorinated products 2c' and 2c''. The product composition of the reaction of 1c with NFSI (1.0 equiv) remained unchanged at lower milling speeds (25 Hz vs 30 Hz), but the use of
  • , we reacted a mixture of NFSI and imidazole (3a) by ball milling. Analysis by NMR spectroscopy of the crude reaction mixture showed that 1-(benzenesulfonyl)imidazole (4a) had been formed in 41% yield (Scheme 3a). Complementarily, 19F NMR spectroscopy of the crude reaction mixture evidenced a
  • distinctive peak at 65.8 ppm in the 19F NMR spectrum (Scheme 3g), which was assigned to phenylsulfonyl fluoride (PhSO2F) [35], a byproduct often obtained in reactions with NFSI [36][37]. Trying to improve the rheology of the reaction mixture and to increase the basicity of the medium, we milled 3a and NFSI in
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Published 07 Feb 2022
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