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Search for "13C" in Full Text gives 1841 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Enhanced reactivity of Li+@C60 toward thermal [2 + 2] cycloaddition by encapsulated Li+ Lewis acid

  • Hiroshi Ueno,
  • Yu Yamazaki,
  • Hiroshi Okada,
  • Fuminori Misaizu,
  • Ken Kokubo and
  • Hidehiro Sakurai

Beilstein J. Org. Chem. 2024, 20, 653–660, doi:10.3762/bjoc.20.58

Graphical Abstract
  • by the higher HOMO level of 3 compared to that of 4. The products were characterized by spectroscopic and spectrometric analyses (Figures S3–S11 in Supporting Information File 1). 1H, and 13C NMR spectra clearly indicated the formation of [2 + 2] monoadducts. 7Li NMR spectra showed a sharp singlet
  • : 155 MHz, 13C: 100 MHz), a Bruker ADVANCE III (1H: 600 MHz) and a Bruker ADVANCE III 700 (1H: 700 MHz, 7Li: 272 MHz, 13C: 176 MHz) spectrometer. Chemical shifts (δ) were reported in parts per million (ppm) relative to residual proton of solvent for 1H (5.32 ppm, CDHCl2), LiCl in D2O for 7Li (0 ppm
  • , external standard), and carbon of the solvent for 13C (53.84 ppm, CD2Cl2). High-resolution matrix-assisted laser desorption ionization (HR-MALDI) mass spectra were obtained on a Bruker solariX 12T mass spectrometer with dithranol as a matrix. UV–vis absorption spectra were measured on a JASCO V-670 and a
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Published 25 Mar 2024

Isolation and structure determination of a new analog of polycavernosides from marine Okeania sp. cyanobacterium

  • Kairi Umeda,
  • Naoaki Kurisawa,
  • Ghulam Jeelani,
  • Tomoyoshi Nozaki,
  • Kiyotake Suenaga and
  • Arihiro Iwasaki

Beilstein J. Org. Chem. 2024, 20, 645–652, doi:10.3762/bjoc.20.57

Graphical Abstract
  • geometry of the remaining double bond at C-18 was established to be trans by comparing the 13C NMR chemical shifts at C-16 and C-21 between 1 and polycavernoside D (5) (Table S1 in Supporting Information File 1) [5]. In addition, a 4J long-range coupling between δH 1.95 (H-26) and δH 2.18 (H-24) and three
  • procedures Optical rotations were measured with a JASCO DIP-1000 polarimeter. UV spectra were recorded on a UV-3600. ECD spectra were measured with JASCO J-1100. IR spectra were recorded on a Bruker ALPHA instrument. All NMR data were recorded on a JEOL ECX-400/ECS-400 spectrometer for 1H (400 MHz) and 13C
  • (100 MHz). 1H NMR chemical shifts (referenced to the residual solvent signal of CHD2OD: δ 3.31, CHCl3: δ 7.26) were assigned using a combination of data from COSY and HMQC experiments. Similarly, 13C NMR chemical shifts (referenced to the solvent signal CD3OD: δ 49.0, CDCl3: δ 77.16) were assigned
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Published 21 Mar 2024

Production of non-natural 5-methylorsellinate-derived meroterpenoids in Aspergillus oryzae

  • Jia Tang,
  • Yixiang Zhang and
  • Yudai Matsuda

Beilstein J. Org. Chem. 2024, 20, 638–644, doi:10.3762/bjoc.20.56

Graphical Abstract
  • ). After large-scale cultivation, 3 was isolated and subjected to nuclear magnetic resonance (NMR) analysis, which suggested that 3 is the C-5′ desmethyl form of preterretonin A [17]. However, several missing signals in the 13C NMR spectrum, likely due to keto–enol tautomerization in the D-ring, hindered
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Published 20 Mar 2024

HPW-Catalyzed environmentally benign approach to imidazo[1,2-a]pyridines

  • Luan A. Martinho and
  • Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2024, 20, 628–637, doi:10.3762/bjoc.20.55

Graphical Abstract
  • reproducible. Unsuccessful substrates for these reactions were also detected (Scheme 4). The use of 2-amino-3-hydroxypyridine provided a complex mixture of products (1H and 13C NMR analysis). When 6-amino-2-thiouracil was used, only the starting materials were recovered. Regarding the aldehyde component, the
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Published 19 Mar 2024

Chemical and biosynthetic potential of Penicillium shentong XL-F41

  • Ran Zou,
  • Xin Li,
  • Xiaochen Chen,
  • Yue-Wei Guo and
  • Baofu Xu

Beilstein J. Org. Chem. 2024, 20, 597–606, doi:10.3762/bjoc.20.52

Graphical Abstract
  • m/z 341.1862 [M − H]− (calcd for C20H25N2O3, 341.1870). Spectroscopic analysis, including 1H NMR, 13C NMR (Table 1), and DEPT, revealed that compound 1 contains three methyl groups, one of which is oxygenated, four methines, three saturated non-protonated carbons, and two ketone carbonyl carbons (δC
  • substructure at C-14 with a methine at C-16, indicated by the methoxy group. The position of the methoxy substituent was established by HMBC correlations, and the 13C NMR data suggested that compound 1 includes a 4-oxo-2,3-dihydro-(1H)-quinolin-3-yl fragment. The planar structure was established from HMBC
  • 335.1719 [M + Na]+ (calcd for C19H24N2O2Na+, 335.1730) and m/z 311.1755 [M − H]− (calcd for C19H23N2O2, 311.1765). Spectroscopic analysis using 1H NMR, 13C NMR, and DEPT (Table 2) indicated that compound 2 comprises two methyl groups, five methines, five saturated non-protonated carbons, and one ketone
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Published 15 Mar 2024

Synthesis of photo- and ionochromic N-acylated 2-(aminomethylene)benzo[b]thiophene-3(2Н)-ones with a terminal phenanthroline group

  • Vladimir P. Rybalkin,
  • Sofiya Yu. Zmeeva,
  • Lidiya L. Popova,
  • Irina V. Dubonosova,
  • Olga Yu. Karlutova,
  • Oleg P. Demidov,
  • Alexander D. Dubonosov and
  • Vladimir A. Bren

Beilstein J. Org. Chem. 2024, 20, 552–560, doi:10.3762/bjoc.20.47

Graphical Abstract
  • were isolated preparatively and fully characterized by IR, 1H, and 13C NMR spectroscopy as well as HRMS and XRD methods. The reverse thermal reaction was catalyzed by protonic acids. N-Acylated compounds exclusively with Fe2+ formed nonfluorescent complexes with a contrast naked-eye effect: a color
  • products 3a–c were comprehensively characterized by IR, 1Н and 13C NMR spectroscopy, HRMS (Supporting Information File 2) as well as by X-ray diffraction analysis. The molecular structure of 3b is shown in Figure 3. The crystal data, details of the data collection and refinements for 3b as well as complete
  • reaction occurred catalytically in the presence of HClO4. A special technique for the preparative synthesis of photoproducts was developed. For the first time in the course of studying N→O acylotropic migrations, O-acylated photoproducts were comprehensively characterized by IR, 1H and 13C NMR spectroscopy
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Published 11 Mar 2024

Synthesis and biological profile of 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines, a novel class of acyl-ACP thioesterase inhibitors

  • Jens Frackenpohl,
  • David M. Barber,
  • Guido Bojack,
  • Birgit Bollenbach-Wahl,
  • Ralf Braun,
  • Rahel Getachew,
  • Sabine Hohmann,
  • Kwang-Yoon Ko,
  • Karoline Kurowski,
  • Bernd Laber,
  • Rebecca L. Mattison,
  • Thomas Müller,
  • Anna M. Reingruber,
  • Dirk Schmutzler and
  • Andrea Svejda

Beilstein J. Org. Chem. 2024, 20, 540–551, doi:10.3762/bjoc.20.46

Graphical Abstract
  • ]pyridine (13c, 54% combined isolated yield). As shown for N-acylated target compounds 16a–f, the acylation of 6-bromo-2,3-dihydro[1,3]thiazolo[4,5-b]pyridines 13a–c, affording target compounds 14a–c, proceeded under mild conditions with a suitable acyl chloride reagent and triethylamine as base in DCM. It
  • ]pyridine 7b had a higher water solubility of 173 mg/L and a lower LogP of 1.59 (pH 2.3). However, the lipophilicity of the new 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines was highly dependent on the substituents. For example, the brominated analogs 13b and 13c showed considerably higher LogP values of 2.88
  • (i.e., 13b) and 3.17 (i.e., 13c). We were thus curious to see how the structural change from a heteroaromatic thiazole unit to a partially saturated thiazoline moiety affected the in vitro and in vivo efficacy of the target compounds. All compounds that were prepared to explore the SAR of substituted
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Published 01 Mar 2024

A new analog of dihydroxybenzoic acid from Saccharopolyspora sp. KR21-0001

  • Rattiya Janthanom,
  • Yuta Kikuchi,
  • Hiroki Kanto,
  • Tomoyasu Hirose,
  • Arisu Tahara,
  • Takahiro Ishii,
  • Arinthip Thamchaipenet and
  • Yuki Inahashi

Beilstein J. Org. Chem. 2024, 20, 497–503, doi:10.3762/bjoc.20.44

Graphical Abstract
  • determined as C12H13NO7S (requiring seven degrees of unsaturation) from the [M + H]+ ion at m/z 316.0484 (calcd. for C12H14NO7S, 316.0485) by HRESIMS. The 1H and 13C NMR spectral data of 1 are listed in Table 1. The 1H NMR and heteronuclear single quantum coherence (HSQC) data indicated the presence of two
  • sp2 methines, one sp3 methine, one sp3 methylene, and one methyl group. The 13C NMR data showed the resonances of twelve carbons, which were classified into six olefinic carbons (including two oxygenated carbons: δC 151.0 and 145.2), three carbonyl carbons, one sp3 methine carbon, one sp3 methylene
  • of 0.5 mL·min−1 and gradient elution with MeOH/H2O with 0.1% FA. Structure elucidation Spectra from 1H NMR at 500 MHz and 13C NMR at 125 MHz were measured in CD3OD using a JNM-ECA500 (JEOL Ltd., Tokyo Japan). Chemical shifts were referenced to CD3OD (3.31 ppm) in the 1H NMR spectra and CD3OD (49.0
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Published 29 Feb 2024

Pseudallenes A and B, new sulfur-containing ovalicin sesquiterpenoid derivatives with antimicrobial activity from the deep-sea cold seep sediment-derived fungus Pseudallescheria boydii CS-793

  • Zhen Ying,
  • Xiao-Ming Li,
  • Sui-Qun Yang,
  • Hong-Lei Li,
  • Xin Li,
  • Bin-Gui Wang and
  • Ling-Hong Meng

Beilstein J. Org. Chem. 2024, 20, 470–478, doi:10.3762/bjoc.20.42

Graphical Abstract
  • )], four aliphatic methylenes, four methines (with two oxygenated and one olefinic), and four exchangeable protons. The 13C NMR spectroscopic data (Table 1) displayed all 16 resonances which were classified by DEPT experiments into the categories of four methyls (including one methoxy), four methylenes
  • should be mentioned that compound 3 was the first sulfur-containing ovalicin sesquiterpenoid, which was previously isolated from Sporothrix sp. FO-4649, but its absolute configuration was not explicitly represented, and their 1H and 13C NMR data were incomplete [10]. Thus, a full assignment of the NMR
  • –6.10). Then, compound 2 (13.7 mg) was isolated by CC on Si gel (CH2Cl2/MeOH, 250:1 to 50:1) and preparative TLC (plate: 20 × 20 cm, developing solvent: ether/acetone 2:1) from Fr. 6.3 (578 mg). Pseudallene A (1): colorless crystals (MeOH); mp 115–117 °C; [α]D25 +20.0 (c 0.4, MeOH); 1H and 13C NMR data
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Published 28 Feb 2024

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
  • 13C{1H} NMR spectra contained signals supporting the presence of ketone (e.g., δC = 185.6 ppm for 5a) and ester (δC = 161.9 ppm for 5a) functionalities. Difluoroketoester products were found to hydrate readily to give gem-diol derivatives during aqueous work-up [39], thus reducing the efficiency of
  • submission numbers: 2288841–2288848. Supporting Information File 2: Experimental procedures, characterization data, and copies of 1H, 19F and 13C{1H} NMR spectra. Acknowledgements We thank Dr Dmitry S. Yufit for conducting X-ray crystallographic studies. Parts of this work have already been published in
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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
  • obtained by us fully correspond to the literature data [19][20]. The 1H and 19F NMR spectra of compounds 7a,b also corresponded to the data given in the literature [21][22]. We present here the spectral data for isomer 6a, as well as the missing data of 13C NMR spectra for iodoolefins 7a,b. It should be
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Published 27 Feb 2024

Development of a chemical scaffold for inhibiting nonribosomal peptide synthetases in live bacterial cells

  • Fumihiro Ishikawa,
  • Sho Konno,
  • Hideaki Kakeya and
  • Genzoh Tanabe

Beilstein J. Org. Chem. 2024, 20, 445–451, doi:10.3762/bjoc.20.39

Graphical Abstract
  • % (12d), and 75% (12e); (d) NaH, NH2SO2Cl, DME, 0 °C to rt, 86% (13a), 81% (13b), 92% (13c), 78% (13d), and 62% (13e); (e) Boc-ʟ-Phe-OSu, Cs2CO3, DMF, rt.; (f) 80% aqueous TFA, rt, two steps 95% (4), 94% (5), 56% (6), 88% (7), 58% (8), 69% (9); (g) methyl-Peg4-NHS ester, Cs2CO3, DMF, rt. Kd values for
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Published 26 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

Facile approach to N,O,S-heteropentacycles via condensation of sterically crowded 3H-phenoxazin-3-one with ortho-substituted anilines

  • Eugeny Ivakhnenko,
  • Vasily Malay,
  • Pavel Knyazev,
  • Nikita Merezhko,
  • Nadezhda Makarova,
  • Oleg Demidov,
  • Gennady Borodkin,
  • Andrey Starikov and
  • Vladimir Minkin

Beilstein J. Org. Chem. 2024, 20, 336–345, doi:10.3762/bjoc.20.34

Graphical Abstract
  • potential for testing as potential donors for organic solar cells or as dye sensitizers for dye-sensitized solar cells [24][25]. Experimental All reagents and solvents were purchased from commercial sources (Aldrich) and used without additional purification. The compounds were characterized by 1H, 13C, and
  • spectrometers Varian UNITY-300 (300 MHz for 1H) and Bruker AVANCE-600 (600 MHz for 1H, 151 MHz for 13C, and 60 MHz for 15N) in CDCl3 solutions. Chemical shifts are reported in ppm using the residual solvent peaks as reference (7.24 ppm for 1H, 77.0 ppm for 13C, and 384 ppm for 15N using nitromethane). Chemical
  • shifts were measured with a precision of 0.01 ppm, and 0.1 Hz for spin–spin coupling constants J. The assignment of resonance peaks was carried out using COSY, HSQC, and 1H,13C as well as 1H,15N HMBC. Melting points were determined using a PTP (M) apparatus and were left uncorrected. IR spectra were
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Published 21 Feb 2024

Spatial arrangements of cyclodextrin host–guest complexes in solution studied by 13C NMR and molecular modelling

  • Konstantin Lebedinskiy,
  • Ivan Barvík,
  • Zdeněk Tošner,
  • Ivana Císařová,
  • Jindřich Jindřich and
  • Radim Hrdina

Beilstein J. Org. Chem. 2024, 20, 331–335, doi:10.3762/bjoc.20.33

Graphical Abstract
  • 2026/5, 121 16 Praha, Czech Republic Department of Inorganic Chemistry, Faculty of Science, Charles University, Hlavova 8, 128 43 Praha, Czech Republic 10.3762/bjoc.20.33 Abstract 13C NMR spectroscopic analyses of Cs symmetric guest molecules in the cyclodextrin host cavity, combined with molecular
  • signals in 13C NMR spectra. This signal split can be correlated to the distance of the guest atoms from the wall of the host cavity and to the spatial separation of binding sites preferred by pairs of prochiral carbon atoms. These measurements complement traditional solid-state analyses, which rely on the
  • crystallization of host–guest complexes and their crystallographic analysis. Keywords: anisotropy; 13C NMR; cyclodextrin; host–guest complexes; Introduction Complexation of organic and inorganic compounds with α-, β-, or γ-cyclodextrins and their derivatives [1] is an established tool used in medicine for drug
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Published 20 Feb 2024

Discovery of unguisin J, a new cyclic peptide from Aspergillus heteromorphus CBS 117.55, and phylogeny-based bioinformatic analysis of UngA NRPS domains

  • Sharmila Neupane,
  • Marcelo Rodrigues de Amorim and
  • Elizabeth Skellam

Beilstein J. Org. Chem. 2024, 20, 321–330, doi:10.3762/bjoc.20.32

Graphical Abstract
  • compound 1 was elucidated by 1D and 2D NMR and HRESIMS/MS. Unguisin B was identified by the 1H and 13C NMR data with the reported data [1][5]. Compound 1 was obtained as a white amorphous solid optically active, with +23.4 (c 0.1, MeOH). Its molecular formula was established as C41H56N8O7 by HRMS ([M + H
  • . The 1H and 13C NMR spectra of 1 revealed the presence of seven amide NH signals between δH 7.43 and 8.44 ppm supported by the amide carbonyl signals at δC 173.1, 172.6, 172.6, 172.1, 172.1, 171.1 and 171.0 ppm (Table 1). An additional NH signal at δH 10.82 ppm and four aromatic signals at δH 7.50
  • data of 1 allowed identifying characteristic 1H and 13C signals very similar to those of unguisin B (2) [1][5], the difference being the replacement of the Phe-4 in 1 by Val-4 in 2. This assignment was confirmed by observation of HMBC correlations from δH 7.98 (NH) and δH 8.44 (NH) to C=O (δC 173.1
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Published 19 Feb 2024

Synthesis of spiropyridazine-benzosultams by the [4 + 2] annulation reaction of 3-substituted benzoisothiazole 1,1-dioxides with 1,2-diaza-1,3-dienes

  • Wenqing Hao,
  • Long Wang,
  • Jinlei Zhang,
  • Dawei Teng and
  • Guorui Cao

Beilstein J. Org. Chem. 2024, 20, 280–286, doi:10.3762/bjoc.20.29

Graphical Abstract
  • investigated the performance of other organic and inorganic bases, but they did not improve the yield (Table 1, entries 8–12). The structure of spiropyridazine-benzosultam 3aa was determined by 1H NMR, 13C NMR, HRMS analysis and single-crystal X-ray crystallography [33]. Further experiments conducted with
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Published 14 Feb 2024

Optimizations of lipid II synthesis: an essential glycolipid precursor in bacterial cell wall synthesis and a validated antibiotic target

  • Milandip Karak,
  • Cian R. Cloonan,
  • Brad R. Baker,
  • Rachel V. K. Cochrane and
  • Stephen A. Cochrane

Beilstein J. Org. Chem. 2024, 20, 220–227, doi:10.3762/bjoc.20.22

Graphical Abstract
  • Supporting Information Supporting Information File 12: Experimental procedures, characterization data, and selected copies of 1H, 13C, and 31P NMR spectra. Acknowledgements We extend our gratitude to Professor Alethea Tabor and Professor Stefan Howorka from University College London for their valuable
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Published 06 Feb 2024

Metal-catalyzed coupling/carbonylative cyclizations for accessing dibenzodiazepinones: an expedient route to clozapine and other drugs

  • Amina Moutayakine and
  • Anthony J. Burke

Beilstein J. Org. Chem. 2024, 20, 193–204, doi:10.3762/bjoc.20.19

Graphical Abstract
  • = 8 Hz, Ar, 1H), 6.79–6.83 (t, J = 8 Hz, Ar, 1H), 6.85–6.87 (d, J = 8 Hz, Ar, 1H), 7.09–7.13 (m, Ar, 3H), 7.49–7.51 (d, J = 8 Hz, Ar, 1H); 13C NMR (CDCl3, 100 MHz) δ 110.42, 114.41, 116.47, 119.48, 119.70, 127.00, 127.04, 128.39, 132.62, 142.45, 143.03; HRESIMS (m/z): [M + H+] calcd for C12H11BrN2
  • °C; 1H NMR (DMSO-d6, 400 MHz) δ 6.87–7.00 (m, Ar, 6H), 7.31–7.35 (t, J = 8 Hz, Ar, 1H), 7.66–7.68 (d, J = 8 Hz, Ar,1H), 7.84 (s, Ar, 1H), 9.85 (s, Ar, 1H); 13C NMR (CDCl3, 100 MHz) δ 119.52, 120.23, 121.17, 121.73, 123.24, 123.40, 124.95, 130.29, 132.56, 133.67, 140.43, 150.92, 168.40; ESIMS (m/z
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Published 31 Jan 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
  • = 11.7, J4,5 = 10.3, J4,3e = 4.8, 1H, H-4), 7.27 (d, JNH,5 = 9.9, 1H, NH), 7.33–7.49 (m, 5H, Ph); 13C NMR (75 MHz, CDCl3, δ, ppm, J, Hz) 37.0 (C-3), 40.1 (CH2Cl), 40.3 (CH2Cl), 49.8 (C-5), 53.1 (OMe), 62.5 (C-9), 70.1 (C-4), 71.5, 71.8 (C-6, C-7), 75.5 (C-8), 88.2 (C-2), 114.1 (q, JC,F = 285, CF3), 114.2
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Published 31 Jan 2024

Synthesis of the 3’-O-sulfated TF antigen with a TEG-N3 linker for glycodendrimersomes preparation to study lectin binding

  • Mark Reihill,
  • Hanyue Ma,
  • Dennis Bengtsson and
  • Stefan Oscarson

Beilstein J. Org. Chem. 2024, 20, 173–180, doi:10.3762/bjoc.20.17

Graphical Abstract
  • -exchange resin, with no apparent presence of tin impurities by NMR when the sequence was executed in this order and sulfated target 2 was obtained in a 66% yield on a one-gram scale. Comparing the 1H,13C HSQC spectra of compounds 1 and 2, there is a clear downfield shift of the H-3’/C-3’ signal from 1 to
  • , Reveleris® silica cartiges 40 μm, Büchi Labortechnik AG®) and Biotage® SP4 HPFC (UV 200–500 nm, Biotage® SNAP KP-Sil 50 μm irregular silica, Biotage® AB). Instrumentation 1H NMR and 13C NMR spectra were recorded on Varian Inova spectrometers at 25 °C in chloroform-d (CDCl3), methanol-d4 (CD3OD), deuterium
  • oxide (D2O) or DMSO-d6 ((CD3)2SO). 1H NMR spectra were standardised against the residual solvent peak (CDCl3, δ = 7.26 ppm; CD3OD, δ = 3.31 ppm; D2O, δ = 4.79 ppm; (CD3)2SO δ = 2.50 ppm); or internal trimethylsilane, δ = 0.00 ppm). 13C NMR spectra were standardised against the residual solvent peak
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Published 30 Jan 2024

Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions

  • Julika Schlosser,
  • Olga Fedorova,
  • Yuri Fedorov and
  • Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 101–117, doi:10.3762/bjoc.20.11

Graphical Abstract
  • the amine 2b gave the corresponding amide 2g in 28% yield. The chloro-substituted derivative 2e was synthesized in a Sandmeyer-reaction from 2b in 20% yield. The products 2a–g were identified and fully characterized by NMR spectroscopy (1H, 13C, COSY, HSQC, and HMBC), elemental analyses, and mass
  • chemicals (Alfa, Merck, Fluorochem or BLDpharm) were of reagent grade and used without further purification. 1H NMR spectra were recorded with a JEOL ECZ 500 (1H: 500 MHz and 13C: 125 MHz) and a Varian VNMR S600 (1H: 600 MHz and 13C: 150 MHz) at T = 25 °C. The 1H NMR and 13C{1H} NMR spectra were referenced
  • to the residual proton signal of the solvent [CD3CN: δ(1H) = 1.94 ppm, δ(13C) = 118.36 ppm or DMSO-d5: δ(1H) = 2.50 ppm, δ(13C) = 39.52 ppm] or to an internal standard in CDCl3 [TMS: δ(1H) = 0.00 ppm, δ(13C) = 0.00 ppm]. Structural assignments were made with additional information from gCOSY, gHSQC
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Published 18 Jan 2024

Multi-redox indenofluorene chromophores incorporating dithiafulvene donor and ene/enediyne acceptor units

  • Christina Schøttler,
  • Kasper Lund-Rasmussen,
  • Line Broløs,
  • Philip Vinterberg,
  • Ema Bazikova,
  • Viktor B. R. Pedersen and
  • Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2024, 20, 59–73, doi:10.3762/bjoc.20.8

Graphical Abstract
  • Systems X10/X50: 40–63 μm). TLC was performed using aluminum sheets covered with silica gel coated with fluorescent indicator. NMR spectra were recorded on a Bruker instrument at 500 MHz and 126 MHz for 1H and 13C NMR, respectively. Deuterated chloroform (CDCl3, 1H = 7.26 ppm, 13C = 77.16 ppm), deuterated
  • CH2Cl2 (CD2Cl2, 1H = 5.32 ppm, 13C = 54.00 ppm), deuterated DMSO ((CD3)2SO, 1H = 2.50 ppm, 13C = 39.53 ppm), deuterated acetone ((CD3)2CO, 1H = 2.05 ppm, 13C = 29.84 ppm), or deuterated benzene (C6D6, 1H = 7.16 ppm, 13C = 128.39 ppm) were used as solvents and internal references. Chemical shift values
  • –7.71 (m, 2H), 7.68 (d, J = 8.0 Hz, 1H), 7.58–7.44 (m, 2H), 7.44–7.35 (m, 3H), 4.50 (s, 4H), 2.44 (s, 3H), 1.43 (s, 9H), 1.36 (s, 9H) ppm; 13C NMR (126 MHz, CDCl3) δ 194.1, 152.7, 151.1, 148.7, 148.0, 144.7, 143.5, 142.3, 142.3, 138.8, 137.1, 135.5, 135.1, 133.6, 132.3, 131.4, 130.4, 129.1, 128.8, 127.7
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Published 15 Jan 2024

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

  • Matthias R. Steiner,
  • Max Schmallegger,
  • Larissa Donner,
  • Johann A. Hlina,
  • Christoph Marschner,
  • Judith Baumgartner and
  • Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

Graphical Abstract
  • purified by recrystallization whereby the solvents used vary depending on the parent Michael acceptor (for details, see Supporting Information File 1). Yields are not optimized and given in Table 1. The synthesized zwitterions were investigated via 1H, 13C and 31P NMR spectroscopy. All synthesized
  • similar phosphonium salt 2,4-di-tert-butyl-6-(triphenylphosphonium)phenolate features this particular signal at 6.27 ppm (4JHH = 2.7 Hz, 3JPH = 14.4 Hz [30]). In the 13C NMR spectra, the chemical shifts of the carbon atoms in positions 1 and 6 of the phenolate unit are particularly noteworthy. In the
  • = 3.9 Hz) [30]. Compared to the parent phosphine 1 (155.9 ppm, 2JPC = 19.3 Hz) [35] a pronounced down-field shift occurred upon adduct formation, which suggests a considerable contribution of a quinonic resonance structure as benzoquinones exhibit 13C NMR shifts of about 188 ppm and hydroquinones of
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Published 10 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
  • students, examples with combined 1D, 2D, and even some heteronuclear spectra can be used [42]. Here, one set including eight examples consisting exclusively of one-dimensional 1H and 13C NMR spectra and eight additional exercises including a combination of 1H, 13C, COSY, HSQC, and HMBC experiments provide
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Published 05 Jan 2024
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