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Search for "NMR" in Full Text gives 3124 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

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
  • assemblies, 2+-BF4− was further treated with NaPF6, LiB(C6F5)4, and NaPCCp for the ion-pair metathesis to afford ion pairs 2+-X− (X− = PF6−, B(C6F5)4−, and PCCp−) in 44–68% yields. The obtained ion pairs were characterized using 1H, 13C, and 19F nuclear magnetic resonance (NMR) and matrix-assisted laser
  • 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
  • , 0.209 mmol, 19%) as a red solid. Rf 0.33 (MeOH/EtOAc/CH2Cl2 1:2:8); 1H NMR (600 MHz, CDCl3, 20 °C) δ (ppm) 7.68 (t, J = 8.4 Hz, 3H, TATA-H), 7.51 (t, J = 7.8 Hz, 3H, Ar-H), 7.44 (d, J = 7.8 Hz, 6H, Ar-H), 6.37 (d, J = 8.4 Hz, 6H, TATA-H), 2.10 (s, 18H, CH3); 13C NMR (151 MHz, CDCl3, 20 °C) δ (ppm
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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
  • corresponding products (3o, 3p) in good yields. All the products obtained were characterized by 1H NMR, 13C NMR and mass spectrometry techniques. A plausible catalytic cycle has been postulated based on a literature study [13], and is shown in Figure 2. With the exposure of photocatalyst to sunlight/LED light
  • 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
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Letter
Published 08 Oct 2024

Machine learning-guided strategies for reaction conditions design and optimization

  • Lung-Yi Chen and
  • Yi-Pei Li

Beilstein J. Org. Chem. 2024, 20, 2476–2492, doi:10.3762/bjoc.20.212

Graphical Abstract
  • . [47]. Literature-extracted yields can be derived from different methods, such as crude yield, isolated yield, quantitative NMR, and liquid chromatography area percentage, and they can also vary in precision due to human bias or equipment quality. HTE data for specific reactions, however, are usually
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Published 04 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
  • , entry 1). Assignment of the relative configurations as cis or trans was achieved by 1H NMR analysis, considering the chemical shifts of the proton in the α-position of the β-lactam nitrogen atom and the geminal protons in the benzylic position (see Supporting Information File 1). The difference in the
  • stereocenter in the five-membered ring was attributed by 1H NMR analysis for 11c. Moreover, the configuration was also confirmed by NOE studies on the two isolated diastereoisomers, which confirmed the preferred trans-isomer formation (see Supporting Information File 1). Analysis of the dr values revealed that
  • intramolecular photoredox reaction. Photoredox-catalyzed intramolecular N-alkylation reactions of various β-lactams. The trans/cis dr was determined by 1H NMR analysis of the crude reaction mixture. Synthesis of the model substrate 14 and its photoredox-catalyzed intramolecular N-alkylation reaction. The trans
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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
  • benzoyl group on the nitrogen atom preventing equilibration to the thermodynamic piperidine product [21]. Basic workup hydrolyzes the trifluoroacetoxy ester in 14 to alcohol 7a. Consideration of the literature NMR data for the three possible isomeric products (i.e., pyrrolidine, piperidine, and
  • 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
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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
  • ) [24]. The solution and the solid-state conformational analysis were supplemented with DFT calculations to understand key conformational drivers. This study adds more data to the field of nuclear magnetic resonance (NMR) spectroscopy of polyhalogenated molecules. It should be noted that the NMR
  • order to decipher the key physical properties of complex pyran inter-halides, we performed 19F NMR analysis of halogenated talose analogues 12–15 (Figure 2). First, all analogues adopt standard 4C1-like conformations. Comparison of the vicinal and geminal coupling constants for each organohalogen
  • −200.55 ppm for 15. Talopyranose analogues 12–15 incorporate a 2,3-cis, 3,4-cis relationship for the halogens. We previously prepared a small set of trihalogenated allopyranose analogues that also included the 2,3-cis, 3,4-cis relationship for the halogens (Figure 1a) [23]. 19F NMR analysis of halogenated
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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
  • , entry 7). Finally, the reaction time was reduced from 24 h to 2.5 h without affecting the yield (Table 1, entry 8). In order to better understand the mechanism of the reaction, an NMR study of the premixing of DDPyOCF3 with PhSeBr was performed. The disappearance of the broad signal of CF3O− and the
  • of the oxidative conditions used (mCPBA [75], H2O2 [75], selectfluor®/H2O [76], SO2Cl2/NaHCO3 (aq) [77][78]), in most cases a complex mixture was observed and no corresponding vinylic compound was detected by NMR. The phenylselenyl moiety could also undergo radical reduction to produce
  • stirred at room temperature for 2.5 h (unless otherwise stated). Note that a yellowish precipitate is formed during the reaction for high yielding substrates. The reaction is monitored by 19F NMR (PhCF3 as internal standard). At the end of the reaction, the content of the vial is transferred to a
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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
  • the complex mixture after mixing 2b with t-BuOK and nitroacetate in DMSO at 80 °C, the unexpected compound 2,3-dihydroxybutyrate anti-10a was isolated as a single isomer. Its production was also detected by 19F NMR from the reaction mixture when nitromethane (16%) and ethyl (diethylphosphono)acetate
  • of the reductive elimination very slow, the intermediary Cu(III) species safely existed until the addition of D2O. Because the significant overlap of NMR peaks was observed due to the quite similar structure of 11a and 11a-D, quantitative analysis of the deuterium content of 11a-D was not possible
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Published 25 Sep 2024

Evaluating the halogen bonding strength of a iodoloisoxazolium(III) salt

  • Dominik L. Reinhard,
  • Anna Schmidt,
  • Marc Sons,
  • Julian Wolf,
  • Elric Engelage and
  • Stefan M. Huber

Beilstein J. Org. Chem. 2024, 20, 2401–2407, doi:10.3762/bjoc.20.204

Graphical Abstract
  • )AuCl was applied with a catalyst loading of 2 mol %, activated by an equal amount of the DAI salt. Due to solubility issues, the reaction had to be performed in methylene chloride instead of chloroform. The gold-catalyzed cyclization reaction (Scheme 2) was followed via 1H NMR spectroscopy (Figure 3
  • , several control experiments were also performed, even though the benchmark reaction has already been established in halogen-bonding activation. In the presence of 2 mol % of either the unactivated gold complex (PPh3)AuCl or the XB donors 1BArF–4BArF + 7BArF, 1H NMR showed no conversion within 18 h
  • , indicating that the activated gold complex is the catalytically active species. Furthermore, stability measurements (1H and 19F NMR) of 1:1 mixtures of the gold complex and the XB donors were performed in order to investigate the stability of the cationic iodonium structures towards the gold complex [28
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Published 23 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
  • in less than 10% yield, determined through 1H NMR analysis, except for Table 1, entries 3 (13%) and 5 (25%). It should also be noted that electrolysis was carried out at room temperature, but the temperature of the reaction mixture increased to 40–50 °C at the end of the electrolysis in every case
  • of dechlorinated diphenylmethanol (1a) in the recovered starting material were confirmed by 1H NMR analysis. These results suggested that 2a was produced from 1a, which was generated in situ by electroreductive dechlorination of 1b. In other words, electroreductive dechlorination of 1b, producing 1a
  • , took place preferentially over electroreductive C(sp3)–O bond cleavage of 1b. It should also be noted that no aromatic carboxylic acids were detected by 1H NMR analysis. In contrast, the electrochemical carboxylation of 1c, containing a fluorine atom, gave a mixture of fluorine-containing carboxylic
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Published 20 Sep 2024

Synthesis, electrochemical properties, and antioxidant activity of sterically hindered catechols with 1,3,4-oxadiazole, 1,2,4-triazole, thiazole or pyridine fragments

  • Daria A. Burmistrova,
  • Andrey Galustyan,
  • Nadezhda P. Pomortseva,
  • Kristina D. Pashaeva,
  • Maxim V. Arsenyev,
  • Oleg P. Demidov,
  • Mikhail A. Kiskin,
  • Andrey I. Poddel’sky,
  • Nadezhda T. Berberova and
  • Ivan V. Smolyaninov

Beilstein J. Org. Chem. 2024, 20, 2378–2391, doi:10.3762/bjoc.20.202

Graphical Abstract
  • , compounds 6–9 are products of alkylation of the nitrogen atom of the heterocycle. Thiones 6–9 were obtained in 40–79% yield (Scheme 1,b). The structures of synthesized compounds were confirmed by the spectral methods IR-, 1H NMR, 13C{1H} NMR spectroscopy (Figures S1–S18 in Supporting Information File 1
  • oxidation peak of the catechol fragment to the cathode region (Figure 7). This is due to the less acceptor nature of the thiazole ring compared to the more electron-deficient oxadiazole cycle, which contains three heteroatoms. In addition, according to NMR spectral data, one proton of the hydroxy group of
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Published 19 Sep 2024

Asymmetric organocatalytic synthesis of chiral homoallylic amines

  • Nikolay S. Kondratyev and
  • Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

Graphical Abstract
  • two enantiotopic faces of acylimine 2, exposing only one face to the attack by the allyl group. The replacement of one isopropoxy (iPrO) group between allylboronate 1 with BINOL was confirmed by ESI-MS and NMR analysis of the reaction mixture. Interestingly, both (E)- and (Z)-crotyl boronates 6 and 8
  • active catalytic species in COBI-catalysed allylations, chemical equilibria in a solution containing catalyst 72, triflic acid, and aldimine 73 were investigated by low-temperature NMR spectroscopy (Scheme 15). Protonation of oxazaborolidine 70 with triflic acid resulted in an 8.3:1 mixture of 71 and 72
  • , in the COBI–imine complex 74 it appears at 8.41 ppm, while in the imine TfOH salt 75 it shows at 9.24 ppm. This detailed NMR investigation sparked further interest in the structure of the transition state of this reaction. An analysis of the potential energy profiles of the two hypothetical pathways
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Published 16 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
  • , indicating that the developed tandem protocol does not depend on the presence of the N-oxide moiety in the parent heterocycle. All synthesized triazinones 1 and 7 were fully characterized by IR, 1H and 13C NMR spectroscopy, and high-resolution mass spectrometry. The structure of compounds 1b and 7h was
  • 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
  • . Supporting Information Supporting Information File 96: Experimental procedures, characterization data of all products, copies of 1H, 13C NMR, 15N spectra of new compounds, DSC curves,X-ray crystallographic data and copies of IR spectra. Acknowledgements The crystal structure determination was performed at
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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
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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
  • iminoiodinanes for the metal-free aziridination of unactivated olefins. 1H NMR and cyclic voltammetry (CV) studies indicate that hydrogen-bonding between HFIP and the iminoiodinane generates an oxidant capable of direct NGT to unactivated olefins. Stereochemical scrambling during aziridination of 1,2
  • catalysis (Table 1, entry 1) [40][41]. In contrast, combination of PhINTs (2.0 equiv) with 1a in HFIP afforded 3a in 67% NMR yield (Table 1, entry 2). Lowering the loading of iminoiodinane 2a to 1.5 or 1.0 equivalents decreased the reaction yield to 28% and 22%, respectively (Table 1, entries 3 and 4
  • unprotected alcohol is tolerated in our procedure, with product 3l delivered at 50% NMR yield; 3l is sensitive to column chromatography, and thus aziridine-opening to a cyclic ether was observed (31% isolated yield) during purification. Aziridination of cis- or trans-4-octene afforded aziridine 3m as a 1.3
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Published 11 Sep 2024

Catalysing (organo-)catalysis: Trends in the application of machine learning to enantioselective organocatalysis

  • Stefan P. Schmid,
  • Leon Schlosser,
  • Frank Glorius and
  • Kjell Jorner

Beilstein J. Org. Chem. 2024, 20, 2280–2304, doi:10.3762/bjoc.20.196

Graphical Abstract
  • properties via descriptors. Apart from molecular vibrations, electronic influences are commonly modelled via global properties of a molecule (such as HOMO/LUMO energies) or local properties (such as natural population analysis (NPA) charges/NMR shifts), as shown in Figure 5 [69][72][88][89]. With respect to
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Published 10 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
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Published 06 Sep 2024

gem-Difluorination of carbon–carbon triple bonds using Brønsted acid/Bu4NBF4 or electrogenerated acid

  • Mizuki Yamaguchi,
  • Hiroki Shimao,
  • Kengo Hamasaki,
  • Keiji Nishiwaki,
  • Shigenori Kashimura and
  • Kouichi Matsumoto

Beilstein J. Org. Chem. 2024, 20, 2261–2269, doi:10.3762/bjoc.20.194

Graphical Abstract
  • (NMR) yield, in which trifluorotoluene (CF3C6H5) was used as an internal standard. The use of Tf2NH (5 equiv or 10 equiv) and Bu4NBF4 (5 equiv) in CH2Cl2 at room temperature gave the corresponding product 2a in up to 83% yield (Table 1, entries 1–5). The use of CF3COOH did not yield 2a at all (Table 1
  • in the presence of the substrate. The total electricity of 3.0 F/mol vs 1a was passed to the solution. Interestingly, the result gave the corresponding difluorinated compound 2a in 29% yield in the case of 8 mA, as shown by 19F NMR analysis. In addition, 2a was obtained in 42% yield by 19F NMR
  • oxidation of method B was conducted by using 8 mA. The reaction of but-3-yn-1-ylbenzene (1b) in method A gave the corresponding compound 2b in 21% isolated yield (Table 2, entry 1). The 19F NMR result indicated 63% yield. Because of the low molecular weight of 2b, the isolated yield might be somewhat lower
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Published 06 Sep 2024

Synthesis and reactivity of the di(9-anthryl)methyl radical

  • Tomohiko Nishiuchi,
  • Kazuma Takahashi,
  • Yuta Makihara and
  • Takashi Kubo

Beilstein J. Org. Chem. 2024, 20, 2254–2260, doi:10.3762/bjoc.20.193

Graphical Abstract
  • , indicating that the high reactivity of the central sp2 carbon. To evaluate the decomposition pathway, the decomposed materials were characterized. Surprisingly, the major compound detected by 1H NMR measurement of the crude material was compound 1, along with di(10-mesityl-9-anthryl)methane (4) as a minor
  • O–O bond cleavage to give compounds 1 and 5 (Scheme 2). Owing to the high reactivity of the DAntM radical, cyclic voltammogram (CV) was measured by using the stable DAntM cation, prepared from compound 3 oxidized by antimony(V) chloride, which can be characterized by 1H, 13C NMR, and UV–vis
  • . Decomposition pathway of the DAntM radical under air conditions. Supporting Information Supporting Information File 81: Synthetic procedure and compound characterization data (1H, 13C NMR, MS, melting point, X-ray crystallography) of new compounds. DFT calculation results and optimized structural Cartesian
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Published 05 Sep 2024

Metal-free double azide addition to strained alkynes of an octadehydrodibenzo[12]annulene derivative with electron-withdrawing substituents

  • Naoki Takeda,
  • Shuichi Akasaka,
  • Susumu Kawauchi and
  • Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2024, 20, 2234–2241, doi:10.3762/bjoc.20.191

Graphical Abstract
  • indicates that the formed double azide adduct is 6a, which is consistent with our previous report [18]. The double azide addition was further investigated by changing the reaction temperature. The rate constant was determined by the temperature-dependent 1H NMR spectra in CDCl3. The reaction kinetics
  • previously reported electron-donating hexyloxy substituents. The addition pattern was experimentally investigated by 2D NMR, which was also supported by DFT calculations. The bistriazole product displayed fluorescence in the visible range with a fluorescence quantum yield of 7.0%. Finally, the developed
  • partially azidated poly(vinyl chloride) (PVA-N3) was prepared by stirring poly(vinyl chloride) and NaN3 in DMF at room temperature overnight. Measurements NMR spectra were recorded using a JEOL mode Al300 (300 MHz) at room temperature. Deuterated chloroform was used as the solvent unless otherwise stated
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Published 04 Sep 2024

Selective hydrolysis of α-oxo ketene N,S-acetals in water: switchable aqueous synthesis of β-keto thioesters and β-keto amides

  • Haifeng Yu,
  • Wanting Zhang,
  • Xuejing Cui,
  • Zida Liu,
  • Xifu Zhang and
  • Xiaobo Zhao

Beilstein J. Org. Chem. 2024, 20, 2225–2233, doi:10.3762/bjoc.20.190

Graphical Abstract
  • by other acids such as H2SO4 and CF3SO3H, the reaction showed poor effectiveness due to the poor solubility of 1a in water (Table 1, entries 4 and 5). Most notably, 2a was an inseparable mixture of keto and enol isomers, reaching a keto/enol ratio of 5:4 as determined by 1H NMR spectroscopy. Thus
  • thioesters and β-keto amides by simply changing reaction conditions. These features, including a good substrate scope, excellent yield and selectivity and ease of scale-up, rendered the green hydrolysis reaction very environment-friendly, practical, and attractive. Experimental 1H and 13C{1H} NMR spectra
  • . Reaction conditions A: 1 (0.25 mmol), DBSA (87.9 mg, 0.25 mmol), H2O (1 mL), reflux, 5 h. Isolated yield is stated. Keto/enol ratio of 2 was determined by 1H NMR spectroscopy. Synthesis of β-keto amides 3. Reaction conditions B: 1 (0.25 mmol), NaOH (0.75 mmol, 30 mg), H2O (1 mL), reflux, 24 h. Isolated
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Published 03 Sep 2024

Electrochemical allylations in a deep eutectic solvent

  • Sophia Taylor and
  • Scott T. Handy

Beilstein J. Org. Chem. 2024, 20, 2217–2224, doi:10.3762/bjoc.20.189

Graphical Abstract
  • partial solubility of ethylene glycol in methoxycyclopentane as ethylene glycol could be clearly seen in the 1H NMR spectrum of the crude reaction extracts. It should also be noted that the lower isolated yields most likely reflect mechanical losses during extraction and chromatographic separation as the
  • funnel with the aid of 10 mL of deionized (DI) water followed by 20 mL of diethyl ether. The organic layer was separated, dried with anhydrous magnesium sulfate, filtered, and the solvent removed in vacuo to afford the crude product, which was first analyzed by 1H NMR spectroscopy and then purified using
  • sulfate, filtered, and the solvent removed in vacuo to afford the crude product, which was first analyzed by 1H NMR spectroscopy and then purified using flash column chromatography. The graphite electrodes were not polished in between reactions, but were rinsed with DI water and then acetone. General Sn
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Published 02 Sep 2024

Heterocycle-guided synthesis of m-hetarylanilines via three-component benzannulation

  • Andrey R. Galeev,
  • Maksim V. Dmitriev,
  • Alexander S. Novikov and
  • Andrey N. Maslivets

Beilstein J. Org. Chem. 2024, 20, 2208–2216, doi:10.3762/bjoc.20.188

Graphical Abstract
  • reaction was expected, Figure 2) with morpholine under previously found conditions (Scheme 2). To our delight, the meta-1,2,4-oxadiazole aniline 3ab, formed by the sequence of aldol-type reactions, was isolated in 80% yield and its structure was confirmed by NMR and single crystal X-ray analysis (CCDC
  • data of new compounds and NMR spectra. Supporting Information File 64: xyz files with Cartesian atomic coordinates for all model structures and CIF-files for compounds 1g, 3ab, 3bb and 3ca. Funding This study was performed under financial support of the Ministry of Science and Higher Education of the
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Published 02 Sep 2024

Natural resorcylic lactones derived from alternariol

  • Joachim Podlech

Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187

Graphical Abstract
  • : Total synthesis and comparison of the NMR spectra revealed that this natural product is identical with altertenuol [41], whose structure was correctly given previously [42]. Furthermore, the originally proposed structures [43] of graphislactones E and F were corrected after total synthesis and
  • comparison of NMR spectra [44]. Occasionally, natural products have been reported more than one time as new compounds and were given several names. Only the first given name should be used and further names are thus obsolete: Verrulactone D is erroneously given in the SciFinder database as synonym for
  • from an unidentified endophytic fungus [124] and later from colletotrichum sp. [125], Lachnum abnorme [126], Diaporthe phragmitis [127] and a further D. sp. [128], and deviantly from the flower buds of the banana species Musa nana [129]. Its structure was determined by NMR spectroscopy [126] and
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Published 30 Aug 2024

Novel truxene-based dipyrromethanes (DPMs): synthesis, spectroscopic characterization and photophysical properties

  • Shakeel Alvi and
  • Rashid Ali

Beilstein J. Org. Chem. 2024, 20, 2163–2170, doi:10.3762/bjoc.20.186

Graphical Abstract
  • purified through silica-gel column chromatography. After successfully synthesizing these easy-to-make yet interesting molecules, they were fully characterized by means of the standard spectroscopic techniques (1H NMR, 13C NMR and HRMS). We are of the opinion that these truxene-based systems will be useful
  • derivatives were successfully characterized and their structures were established by means of the 1H and 13C NMR spectroscopy, besides further confirmation by mass spectrometry (see Supporting Information File 1). The UV–vis absorption, emission and time-resolved fluorescence spectra Emission and absorption
  • like 1H NMR, 13C NMR, and mass spectral data. The preliminary UV–vis absorption as well as fluorescence emission spectral data for thus prepared truxene-based compounds were recorded in chloroform and compared as well. Additionally, time-resolved fluorescence lifetime decays were also measured for thus
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Published 29 Aug 2024
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