Study of the interaction of 2H-furo[3,2-b]pyran-2-ones with nitrogen-containing nucleophiles

• Constantine V. Milyutin,
• Andrey N. Komogortsev and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2025, 21, 556–563, doi:10.3762/bjoc.21.44

• , 13C NMR spectroscopy and high-resolution MS. 1H NMR spectra of obtained products contain characteristic signals of the protons of the methyl group in the region δ 1.72–2.16 ppm and proton of pyranone fragment in the region δ 5.98–6.62 ppm. Besides that, the key structures of synthesized products were

• Supporting Information File 2: General information, characterization data, NMR spectra and crystallographic data of synthesized compounds. Acknowledgements Crystal structure determination was performed in the Department of Structural Studies of Zelinsky Institute of Organic Chemistry, Moscow.

Asymmetric synthesis of β-amino cyanoesters with contiguous tetrasubstituted carbon centers by halogen-bonding catalysis with chiral halonium salt

• Yasushi Yoshida,
• Maho Aono,
• Takashi Mino and
• Masami Sakamoto

Beilstein J. Org. Chem. 2025, 21, 547–555, doi:10.3762/bjoc.21.43

• : Experimental procedures, characterization data, NMR spectra, and HPLC chromatograms. Funding This research was funded by an IAAR Research Support Program (Chiba Halogen Science: Halogen-Linkage of Molecular Functions); Chiba University Open Recruitment for International Exchange Program, Chiba University

Vinylogous functionalization of 4-alkylidene-5-aminopyrazoles with methyl trifluoropyruvates

• Judit Hostalet-Romero,
• Laura Carceller-Ferrer,
• Gonzalo Blay,
• Amparo Sanz-Marco,
• José R. Pedro and
• Carlos Vila

Beilstein J. Org. Chem. 2025, 21, 533–540, doi:10.3762/bjoc.21.41

• copies of 1H NMR and 13C NMR spectra. Acknowledgements Access to NMR, MS, and X-ray facilities from the Servei Central de Suport a la Investigació Experimental (SCSIE)-UV and the NMR U26 facility of ICTS “NANBIOSIS” is acknowledged. Funding L.C.-F. thanks the Universitat de València for a predoctoral

Cryptophycin unit B analogues

• Thomas Schachtsiek,
• Jona Voss,
• Maren Hamsen,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2025, 21, 526–532, doi:10.3762/bjoc.21.40

• free of charge from the Cambridge Crystallographic Data Centre (CCDC) via https://www.ccdc.cam.ac.uk/structures under reference number CCDC 2400694 for Boc-ᴅ-Phe(4-NHMe)-OMe (7). Supporting Information File 12: Experimental section, NMR spectra and cellular proliferation assays. Acknowledgements We

Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene

• Long K. San,
• Sebastian Balser,
• Brian J. Reeves,
• Tyler T. Clikeman,
• Yu-Sheng Chen,
• Steven H. Strauss and
• Olga V. Boltalina

Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39

• used for the perfluorobenzylation of PERY were used [22]. 9,10-ANTH(Br)2 and BnFI were dissolved and heated to 160 °C in PhCN in the presence of either Cu powder (22 h) or Na2S2O3 (4 h). According to the 1H NMR spectra of the filtered product mixtures, the reaction with Cu showed poor conversion, but

• Information File 1). In the 19F NMR spectra of 9,10-ANTH(BnF)2 (Figure 1) and 9-ANTH(BnF) (Figure S4 in Supporting Information File 1), only four resonances in a 2:2:1:2 ratio were observed, commensurate with the previously reported data for compounds bearing BnF groups [18][29]. The 19F resonances of the CF2

• ) were used as received. Instrumentation 19F (376 MHz) and 1H (400 MHz) NMR spectra were recorded using a Varian INOVA 400 instrument with a trace amount of C8H4F6 (δ(19F) = −66.35 ppm) added as the internal standard. UV–vis spectra were recorded using a Cary 500 UV–VIS–NIR. Emission spectra of the LED

Synthesis of the aggregation pheromone of Tribolium castaneum

• Biyu An,
• Xueyang Wang,
• Ao Jiao,
• Qinghua Bian and
• Jiangchun Zhong

Beilstein J. Org. Chem. 2025, 21, 510–514, doi:10.3762/bjoc.21.38

• )-10. Synthesis of the aggregation pheromone of Tribolium castaneum. Supporting Information Supporting Information File 6: General information, synthesis of compounds 1–12, research on the optical purity of chiral alcohols (R)- and (S)-4, and copies of 1H, 13C and 19F NMR spectra. Funding This

Unprecedented visible light-initiated topochemical [2 + 2] cycloaddition in a functionalized bimane dye

• Metodej Dvoracek,
• Brendan Twamley,
• Mathias O. Senge and
• Mikhail A. Filatov

Beilstein J. Org. Chem. 2025, 21, 500–509, doi:10.3762/bjoc.21.37

• ¹H NMR spectra remained unchanged compared to the neat compounds (Figures S1, S3, and S5, Supporting Information File 1), confirming that the reaction occurs selectively in the solid state. Cl2B was also irradiated in DCM with the same 405 nm LEDs, in a quartz fluorescence cuvette. A UV–vis spectrum

• , Figure S15). Following this, more 1H NMR irradiation studies were conducted, where each bimane was dissolved in dichloromethane-d2, and irradiated using the same 405 nm light source for 1.25 h. The NMR spectra showed that no [2 + 2] dimer yield was achieved (Supporting Information File 1, Figures S8–S10

Synthesis of N-acetyl diazocine derivatives via cross-coupling reaction

• Thomas Brandt,
• Pascal Lentes,
• Jeremy Rudtke,
• Michael Hösgen,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2025, 21, 490–499, doi:10.3762/bjoc.21.36

• /data_request/cif. Cambridge CB2 1EZ, UK; fax: +44 1223 336033. Supporting Information File 14: Synthetic procedures, UV–vis and NMR switching experiments, copies of UV–vis and NMR spectra, and X-ray crystallographic data. Funding The authors thankfully acknowledge financial support by the Deutsche

Synthesis of electrophile-tethered preQ₁ analogs for covalent attachment to preQ₁ RNA

• Laurin Flemmich and
• Ronald Micura

Beilstein J. Org. Chem. 2025, 21, 483–489, doi:10.3762/bjoc.21.35

• (16) see Supporting Information File 1. Syntheses of haloalkyl- and mesyloxyalkyl-modified preQ1 as and DPQ1 ligands. Supporting Information Supporting Information File 12: Experimental part, HPLC analysis of preQ1 and NMR spectra. Acknowledgements We thank Clemens Eichler (University of Innsbruck

Electrochemical synthesis of cyclic biaryl λ³-bromanes from 2,2’-dibromobiphenyls

• Andrejs Savkins and
• Igors Sokolovs

Beilstein J. Org. Chem. 2025, 21, 451–457, doi:10.3762/bjoc.21.32

• Cambridge Crystallographic Data Centre and allocated the deposition number CCDC 2404146. Supporting Information File 6: Experimental procedures, analytical and spectroscopic data for new compounds, copies of NMR spectra, and X-ray crystallographic data. Acknowledgements The authors thank Dr. Sergey

New tandem Ugi/intramolecular Diels–Alder reaction based on vinylfuran and 1,3-butadienylfuran derivatives

• Yuriy I. Horak,
• Roman Z. Lytvyn,
• Andrii R. Vakhula,
• Yuriy V. Homza,
• Nazariy T. Pokhodylo and
• Mykola D. Obushak

Beilstein J. Org. Chem. 2025, 21, 444–450, doi:10.3762/bjoc.21.31

• , compound characterizations, and NMR spectra. Funding The authors are thankful to the Ministry of Education and Science of Ukraine and Simons Foundation (Award Numbers: 1290588) for financial support.

Identification and removal of a cryptic impurity in pomalidomide-PEG based PROTAC

• Bingnan Wang,
• Yong Lu and
• Chuo Chen

Beilstein J. Org. Chem. 2025, 21, 407–411, doi:10.3762/bjoc.21.28

• the PEG chain on the relative retention time of 8 and 9 on HPLC. Supporting Information Supporting Information File 18: Computational details, general experimental information, synthetic procedures, compound characterization data, and copies of NMR spectra. Funding This work is supported by the NIH

Synthesis, structure, ionochromic and cytotoxic properties of new 2-(indolin-2-yl)-1,3-tropolones

• Yurii A. Sayapin,
• Eugeny A. Gusakov,
• Inna O. Tupaeva,
• Alexander D. Dubonosov,
• Igor V. Dorogan,
• Valery V. Tkachev,
• Anna S. Goncharova,
• Gennady V. Shilov,
• Natalia S. Kuznetsova,
• Svetlana Y. Filippova,
• Tatyana A. Krasnikova,
• Yanis A. Boumber,
• Alexey Y. Maksimov,
• Sergey M. Aldoshin and
• Vladimir I. Minkin

Beilstein J. Org. Chem. 2025, 21, 358–368, doi:10.3762/bjoc.21.26

• 1,2-benzoquinone and o-chloroanil, respectively [1][25]. The structures of compounds 7 and 8 obtained by methods A and B were confirmed by 1H NMR, IR spectroscopy and mass spectrometry (Supporting Information File 2). A distinctive feature of the 1H NMR spectra of 7 in CDCl3 is the signal of the

• tropolone ring proton, which appears at 6.9 ppm. A characteristic specificity of the 1H NMR spectra of compounds 7 and 8 is the presence of signals of hydroxy group protons forming a strong hydrogen bond with the indoline nitrogen atom, which closes the six-membered chelate cycle. These signals are observed

• tautomeric forms. To reveal the predominance of either the (NH) or (OH) tautomeric form of compounds 7a, 7b, 8a, and 8b in solution depending on the nature of the solvent, we carried out a detailed study using compound 7a. A complete signal assignment of 1H and 13C NMR spectra was carried out, based on

Synthesis, characterization, antimicrobial, cytotoxic and carbonic anhydrase inhibition activities of multifunctional pyrazolo-1,2-benzothiazine acetamides

• Ayesha Saeed,
• Shahana Ehsan,
• Muhammad Zia-ur-Rehman,
• Erin M. Marshall,
• Sandra Loesgen,
• Abdus Saleem,
• Simone Giovannuzzi and
• Claudiu T. Supuran

Beilstein J. Org. Chem. 2025, 21, 348–357, doi:10.3762/bjoc.21.25

• FTIR spectroscopy as well as HRMS. Table 1 shows the different substituents (R groups) for the synthesized compounds 7a–n. The 1H NMR spectra of compounds 7a–h showed one distinct singlet at 4.92 to 5.12 ppm for the two protons of one methylene group (Figure 2b’), a singlet for the NH proton in the

• range of 10.03 to 10.40 ppm, and another singlet for the OH proton in the range of 13.00 to 13.20 ppm (Figure 2a’). The presence of a singlet near 13 ppm for the OH proton confirms that the compounds 7a–h are N-alkylated. The 1H NMR spectra of compounds 7i–n showed two distinct singlets from 4.90 to

• compounds 7a–h and 7i–n shared a singlet for the N-methyl protons in the range of 3.07 to 3.10 ppm. Signals for aromatic protons were recorded from 6.70 to 8.19 ppm depending upon the extent of shielding/deshielding. The 13C NMR spectra exhibited distinct signals for the synthesized compounds 7a–h: one

Synthesis of new condensed naphthoquinone, pyran and pyrimidine furancarboxylates

• Kirill A. Gomonov,
• Vasilii V. Pelipko,
• Igor A. Litvinov,
• Ilya A. Pilipenko,
• Anna M. Stepanova,
• Nikolai A. Lapatin,
• Ruslan I. Baichurin and
• Sergei V. Makarenko

Beilstein J. Org. Chem. 2025, 21, 340–347, doi:10.3762/bjoc.21.24

• data, they luminesce in DMSO solution when irradiated with light at wavelengths of 352 and 283 nm. Compounds 7a–f are capable of existing as lactim–lactam tautomers due to the presence of an amide fragment in their structure (Scheme 7). At the same time, the 1H and 13C NMR spectra of compounds 7a–f

• indicate their individuality. The presence of a broadened signal in the 1H NMR spectra (DMSO-d6) in the region of 12.49–12.84 ppm and a C4 signal in the 13C NMR spectra (DMSO-d6) in the region of 158.1–159.0 ppm does not allow us to unambiguously determine the tautomeric form of compounds 7a–f in solution

• = 10−5 mol/L). 1Н, 13С{1H}, 1H-13C HMQC, and 1H-13C HMBC NMR spectra were registered on a Jeol ECX–400A instrument at 400 (for 1H nuclei) and 100 MHz (for 13С nuclei) in CDCl3 (δH 7.26, δC 77.16 ppm) and DMSO-d6 (δH 2.47, δC 40.0 ppm) using residual signals of the nondeuterated solvent as the

Synthesis and characterizations of highly luminescent 5-isopropoxybenzo[rst]pentaphene

• Islam S. Marae,
• Jingyun Tan,
• Rengo Yoshioka,
• Zakaria Ziadi,
• Eugene Khaskin,
• Serhii Vasylevskyi,
• Ryota Kabe,
• Xiushang Xu and
• Akimitsu Narita

Beilstein J. Org. Chem. 2025, 21, 270–276, doi:10.3762/bjoc.21.19

• BPP 2 and BPP-OiPr 3. Supporting Information Supporting Information File 114: Experimental and computational details, X-ray crystallography, synthesis and characterization of new compounds, additional PL, mass, and NMR spectra, and theoretical calculations. Acknowledgements We appreciate the help

Three-component reactions of conjugated dienes, CH acids and formaldehyde under diffusion mixing conditions

• Dmitry E. Shybanov,
• Maxim E. Kukushkin,
• Eugene V. Babaev,
• Nikolai V. Zyk and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2025, 21, 262–269, doi:10.3762/bjoc.21.18

• alcohol 2. Its 1H NMR spectrum contained a triplet with a coupling constant of 5.1 Hz at 5.52 ppm and a doublet at 4.30 ppm. In methanol, ethanol and petroleum ether, with an increasing reaction time, a significant amount of product 3 was observed in the 1H NMR spectra of the mixtures, as identified by

• was confirmed through the three-component reaction with acetylacetone, in which only the product 7 was formed (according to 1H NMR spectra of the reaction mixture). Stereoselective interactions between methylidene adducts and cyclopentadiene were confirmed for three-component reactions involving

• was also studied using isoprene as an example. In reactions involving Meldrum's acid, the formation of an inseparable mixture of the two stereoisomeric products 14a and 14b in a ratio of 95:5 was detected with a yield of 91%, the 1H NMR spectra of which coincided with those described in the literature

Synthesis of disulfides and 3-sulfenylchromones from sodium sulfinates catalyzed by TBAI

• Zhenlei Zhang,
• Ying Wang,
• Xingxing Pan,
• Manqi Zhang,
• Wei Zhao,
• Meng Li and
• Hao Zhang

Beilstein J. Org. Chem. 2025, 21, 253–261, doi:10.3762/bjoc.21.17

• , and copies of NMR spectra. Funding This work was supported by the Talent Project of Fuyang Normal University (No. XJRCXM202232), the College Students Innovative Entrepreneurial Training Plan Program (No. S02310371028), The Natural Science Foundation of Higher Education Institutions in Anhui Province

Effect of substitution position of aryl groups on the thermal back reactivity of aza-diarylethene photoswitches and prediction by density functional theory

• Misato Suganuma,
• Daichi Kitagawa,
• Shota Hamatani and
• Seiya Kobatake

Beilstein J. Org. Chem. 2025, 21, 242–252, doi:10.3762/bjoc.21.16

• previous work [56][57], whereas compounds N4 and I1–I4 were synthesized according to Scheme 2 in the Experimental section. The chemical structures of all compounds were confirmed by 1H NMR and 13C NMR spectroscopy and high-resolution mass spectrometry. 1H NMR and 13C NMR spectra are shown in Supporting

Visible-light-promoted radical cyclisation of unactivated alkenes in benzimidazoles: synthesis of difluoromethyl- and aryldifluoromethyl-substituted polycyclic imidazoles

• Yujun Pang,
• Jinglan Yan,
• Nawaf Al-Maharik,
• Qian Zhang,
• Zeguo Fang and
• Dong Li

Beilstein J. Org. Chem. 2025, 21, 234–241, doi:10.3762/bjoc.21.15

• . Optimization of reaction conditions.a Supporting Information Supporting Information File 102: Experimental procedures, product characterization, and copies of NMR spectra. Funding We are grateful to the Scientific Research Project of Hubei Education Department (T2020023 and Q20211402) and the open project of

Streamlined modular synthesis of saframycin substructure via copper-catalyzed three-component assembly and gold-promoted 6-endo cyclization

• Asahi Kanno,
• Ryo Tanifuji,
• Satoshi Yoshida,
• Sota Sato,
• Saori Maki-Yonekura,
• Kiyofumi Takaba,
• Jungmin Kang,
• Kensuke Tono,
• Koji Yonekura and
• Hiroki Oguri

Beilstein J. Org. Chem. 2025, 21, 226–233, doi:10.3762/bjoc.21.14

• by small crystal analysis using an X-ray free-electron laser (XFEL) [54][55]. aSee Supporting Information File 1 for details. Supporting Information Supporting Information File 100: The experimental procedures and characterization data, including copies of NMR spectra and X-ray crystallographic

Heteroannulations of cyanoacetamide-based MCR scaffolds utilizing formamide

• Marios Zingiridis,
• Danae Papachristodoulou,
• Despoina Menegaki,
• Konstantinos G. Froudas and
• Constantinos G. Neochoritis

Beilstein J. Org. Chem. 2025, 21, 217–225, doi:10.3762/bjoc.21.13

• methods, synthetic procedures, analytical data and exemplary copies of NMR spectra of novel compounds. Supporting Information File 97: CheckCIF report for 7b. Supporting Information File 98: CIF file for 7b. Acknowledgements We acknowledge the mass spectrometry facility of the University of Crete

Quantifying the ability of the CF₂H group as a hydrogen bond donor

• Matthew E. Paolella,
• Daniel S. Honeycutt,
• Bradley M. Lipka,
• Jacob M. Goldberg and
• Fang Wang

Beilstein J. Org. Chem. 2025, 21, 189–199, doi:10.3762/bjoc.21.11

• species, the counteranion is BF4−. C) Possible interactions that interfere with the titration outcomes. A) HB complex formation between a donor and tri-n-butylphosphine oxide. B) 1H NMR spectra of 2b (5.0 mM) in the presence of different concentrations of tri-n-butylphosphine oxide in anhydrous CD3CN at

Hydrogen-bonded macrocycle-mediated dimerization for orthogonal supramolecular polymerization

• Wentao Yu,
• Zhiyao Yang,
• Chengkan Yu,
• Xiaowei Li and
• Lihua Yuan

Beilstein J. Org. Chem. 2025, 21, 179–188, doi:10.3762/bjoc.21.10

• 2444.3405, respectively. Stacked 1H NMR spectra (CDCl3/CD3CN 1:1, v/v, 400 MHz, 298 K) of G1 upon addition of different equiv of H1 ([G1] = 1.0⋅10−3 M). (a) 0.0 equiv, (b) 0.2 equiv, (c) 0.4 equiv, (d) 0.6 equiv, (e) 0.8 equiv, (f) 1.0 equiv, (g) 1.2 equiv, (h) 1.4 equiv, and (i) only H1. Single-crystal X

• the π–π-stacking distances (d[π···π] = 3.3–3.4 Å) between H2 and G1. The side chains of H2 were replaced by a methyl group, all hydrogen atoms except amide groups, solvent molecules, and counterions were omitted for clarity. Stacked 1H NMR spectra (CDCl3/CD3CN 1:1, v/v, 400 MHz, 298 K) of G2 upon

• ). Stacked 1H NMR spectra (CDCl3/CD3CN 1:1, v/v, 400 MHz, 298 K) of G2 and Zn2+ upon addition of different equiv of H1 ([G2 + Zn2+] = 1.0⋅10−3 M). (a) 0.0 equiv, (b) 0.4 equiv, (c) 0.6 equiv, (d) 0.8 equiv, (e) 1.0 equiv, (f) 1.2 equiv, (g) 1.4 equiv, and (h) only H1. Specific viscosity of the linear

Facile one-pot reduction of β-nitrostyrenes to phenethylamines using sodium borohydride and copper(II) chloride

• Laura D’Andrea and
• Simon Jademyr

Beilstein J. Org. Chem. 2025, 21, 39–46, doi:10.3762/bjoc.21.4

• aromatic compounds. Experimental NMR spectra were recorded on Bruker Avance 400 MHz or Bruker Avance III HD 600 MHz spectrometers. Residual solvent peaks (CDCl3, D2O, CD3OD, (CD3)2SO) were used as internal standard (7.26, 4.79, 3.31, and 2.50 ppm for 1H, and 77.16, 49, and 39.52 ppm for 13C, respectively

• (entries 1–6). The isolated product yields were obtained by performing the reactions at 80 °C for the time indicated beside each product. For more details, see the experimental section below. Supporting Information Supporting Information File 68: 1H and 13C NMR spectra of the synthesized compounds, the