Kinetic resolution of racemic planar-chiral vinylcymantrenes by molybdenum-catalyzed asymmetric metathesis dimerization

• Haruna Imazu,
• Hitoshi Izu,
• Yasuhiro Ohki and
• Masamichi Ogasawara

Beilstein J. Org. Chem. 2026, 22, 568–574, doi:10.3762/bjoc.22.42

• substrates rac-1a–c. Molybdenum-catalyzed asymmetric metathesis dimerization/kinetic resolution of racemic vinylcymantrenes 1a–c.a Supporting Information Supporting Information File 19: Experimental procedures, NMR spectra (1H and 13C) for all the new compounds, and chiral HPLC chromatograms. Supporting

Experimental and DFT studies on the regioselective methanolysis of 5-azido-9-oxabicyclo[6.1.0]nonan-4-yl 4-nitrobenzoate isomers

• İlknur Polat,
• Selçuk Eşsiz and
• Emine Salamci

Beilstein J. Org. Chem. 2026, 22, 547–556, doi:10.3762/bjoc.22.40

• intermediate 12 with the anti-face of the benzoate to give compound 14. Similarly, the chloride anion attacks by SN2-type the epoxide ring of intermediate 15 to give the sole product 16. The structure of acetate 11 was investigated using 1D (1H and 13C) and 2D (COSY, NOESY, NOE-diff, and HMQC) NMR

• to design pharmacological tools in the future. Experimental General information Melting points are uncorrected. Infrared spectra were obtained from solution in 0.1 mm cells or KBr pellets on an FT-IR Mattson 1000 instrument. The 1H and 13C NMR spectra were recorded on 400 (100) MHz Varian or 400 (100

• . Purification by silica gel column chromatography eluting with EtOAc/hexane 5:95 provided azidol 7 [23] as slightly yellow oil (2.47 g, 14.77 mmol, 92%, lit. [23] 71%). 1H NMR (400 MHz, CDCl3) δ 5.69–5.61 (m, 1H), 5.60–5.52 (m, 1H), 3.79–3.65 (m, 2H), 2.56–2.36 (m, 2H), 2.27–2.09 (m, 4H), 1.81–1.67 (m, 2H); 13C

Melifoliox B, a novel phloroglucin derivative isolated from Melicope barbigera (Rutaceae) and synthesis of new oxidation products from melifoliones A and B

• Horst Weber,
• Kim-Thao Tran-Cong,
• Bernhard Mayer,
• Guido J. Reiss,
• Iryna S. Konovalova,
• Marc S. Appelhans,
• Kenneth R. Wood and
• Claus M. Passreiter

Beilstein J. Org. Chem. 2026, 22, 535–546, doi:10.3762/bjoc.22.39

• signals detected in the 13C NMR spectrum of 4 (Table 2) could be assigned by careful analysis of the 2D-NMR spectra (HSQC and HMBC). The position of the acetyl group was confirmed by a cross peak between C-2 and the protons of the acetyl-methyl group in the HMBC spectrum and by interactions between the

• ). The chemical shift values of C-6a and C-10a in the 13C NMR spectrum of 4 compared to 2 can be explained by the effect of the new OH-group at C-10b. The γ-position of C-6a leads to a high field shift (from 46.1 to 35.8 ppm) while C-10a shows the opposite effect (from 27.5 to 44.1 ppm), due to its β

• crystals. The high-resolution mass spectrum gave a protonated mol peak at 279.1226 indicating the formula C15H19O5. Compared to melifoliones this means a loss of 3 C-atoms. Based on the NMR spectra (1H, 2D-COSY, 13C, HSQC, HMBC) the structure of the oxidation product was determined as the spirofuranone 11

Get a better glimpse on sequential photoreactions of trisnorbornadienes with ¹⁹F NMR spectroscopy

• Julian Felix Maria Hebborn,
• Ben Eric Merten,
• Thomas Paululat and
• Heiko Ihmels

Beilstein J. Org. Chem. 2026, 22, 527–534, doi:10.3762/bjoc.22.38

• trisnorbornadiene 1f was synthesized in 36% yield through a Suzuki–Miyaura coupling reaction of tribromotrifluorobenzene 3 with the 2-borononorbornadiene 1e (Scheme 2) [43]. The product 1f was identified and fully characterized by NMR spectroscopy (1H, 13C, 19F, COSY, HSQC, HMBC), mass spectrometry, melting point

• '-H, 5'''-H, 5'''-H), 6.94 (dd, 3J = 5.0 Hz, 3J = 2.4 Hz, 3H, 6'-H, 6''-H, 6'''-H), 7.00 (d, 3J = 2.4 Hz, 3H, 3'-H, 3''-H, 3'''-H); 13C NMR (125 MHz, CDCl3) δ 50.7 (C4', C4'', C4'''), 54.6 (C1', C1'', C1'''), 73.1 (C7', C7'', C7'''), 111.2 (C1, C3, C5), 143.1 (C5', C5'', C5'''), 143.4 (C6', C6'', C6

Synthesis and uranyl(VI) extraction performance of a calix[4]pyrrole–tetrahydroxamic acid receptor

• Sara Karnib,
• Rana Baydoun,
• Wissam Zaidan,
• Nancy AlHaddad,
• Omar El Samad,
• Bilal Nsouli,
• Francine Cazier-Dennin and
• Pierre-Edouard Danjou

Beilstein J. Org. Chem. 2026, 22, 486–494, doi:10.3762/bjoc.22.36

• % yield. Its structure was confirmed by 1H NMR, 13C NMR, and HRMS. The uranium(VI) extraction efficiency of PCP HA was evaluated by solid–liquid extraction experiments, using uranyl acetate as the uranium source, with measurements performed by gamma spectroscopy. PCP HA demonstrated good performance

• %). The structure of PCP HA was fully characterized by 1H NMR and 13C NMR (DMSO-d6) as well as by HRMS (ESI+) (Figures S3–S6, and S9 in Supporting Information File 1). In the 1H NMR spectrum, two sets of singlets at 4.41 and 4.76 ppm (CH2) were attributed to the –O=C–CH2–O– groups of the E/Z isomers of

• industrial effluent remediation or for the challenging task of uranium extraction from seawater [79]. Experimental Detailed synthetic procedures, compound characterization (1H and 13C NMR, HRMS), and uranyl extraction protocols, including pH and ligand-to-metal ratio studies, are described in Supporting

Structural reassignment of compound 968, an allosteric glutaminase inhibitor

• Lindsey A. Albertelli,
• Sainabou Jallow,
• Chun Li and
• Scott M. Ulrich

Beilstein J. Org. Chem. 2026, 22, 455–460, doi:10.3762/bjoc.22.33

• , 1H), 7.71 (dd, J = 8.7, 2.3 Hz, 1H), 7.04 (d, J = 8.7 Hz, 1H), 2.93 (s, 6H); 13C NMR (100 MHz, CDCl3) δ 189.7, 156.9, 136.1, 131.1, 130.0, 119.5, 116.7, 43.6. 12-(3-Bromo-4-(dimethylamino)phenyl)-8,9,10,12-tetrahydro-9,9-dimethylbenzo[a]acridin-11(7H)-one (2); suggested revised structure for compound

• ), 2.51 (s, 6H), 2.39 (d, J = 16.5 H, 1Hz), 2.18 (d, J = 16.0 Hz, 1H), 2.02 (d, J = 16.0 Hz, 1H), 0.99 (s, 3H), 0.85 (s, 3H). One diastereotopic methylene hydrogen is obscured by the residual solvent peak at 2.47 ppm; 13C NMR (100 MHz, DMSO-d6) δ 193.72, 151.37, 149.50, 143.73, 134.80, 132.80, 131.69

Synthesis and stereochemical analysis of dynamic planar chiral oxa[7]orthocyclophene

• Yukiho Hashimoto,
• Yuuya Kawasaki,
• Kazunobu Igawa and
• Katsuhiko Tomooka

Beilstein J. Org. Chem. 2026, 22, 436–442, doi:10.3762/bjoc.22.30

• procedures, characterization data, copies of 1H and 13C NMR spectra, and optimized geometries of DFT calculations. Supporting Information File 26: Crystallographic information file of compound 1ac. Acknowledgements We thank K. Imamura (Evaluation center of material properties, IMCE Kyushu University) for

Synthesis and anti-cancer activity of naphthalimide–organylselanyl conjugates

• Rajkumar Ravi and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2026, 22, 416–435, doi:10.3762/bjoc.22.29

• 1.80 ppm and one triplet at 3.13 ppm were attributed to the remaining methylene protons located near the selenium atom [51]. In the 13C NMR spectra, distinct chemical shift differences were observed between compounds 7 and 8, due to the small structural differences between them. For compound 7, with

• reference to 13C NMR signals of the starting material 12, the 13C NMR spectrum of compound 7 exhibits four additional aromatic carbon resonances, which are consistent with the phenyl ring carbons of phenyl selanyl function tethered to the naphthalimide core. The signal at 142 ppm is assigned to the ipso

• equivalence of the ortho and meta carbon pairs, confirming the proposed structure. In contrast, with reference to the 13C NMR signals of starting material 12, compound 8 exhibited eight new 13C NMR peaks in the aliphatic region (14–32 ppm), which is attributed to the incorporation of an octyl selenide unit

Cone p-aminocalix[4]arenes enriched with ‘clickable’ alkyne or azide functionalities

• Ilia Korniltsev,
• Vasily Bazhenov,
• Alexander Gorbunov,
• Dmitry Cheshkov,
• Stanislav Bezzubov,
• Vladimir Kovalev and
• Ivan Vatsouro

Beilstein J. Org. Chem. 2026, 22, 399–415, doi:10.3762/bjoc.22.28

• calixarenes 12 and 13, 1H,13C HMBC spectra were acquired (Figure 2), which clearly showed that the nitro groups are attached to the propylated aromatic units of the macrocycle in both cases. Notably, the correlations showed that the signals from the nitrated calixarene aromatic units appeared upfield-shifted

• corresponding tetraureacalix[4]arenes 47–51 (Scheme 9), the structures of which were unambiguously confirmed by their 1H NMR and 13C NMR spectra obtained from solutions in polar DMSO-d6. Being calix[4]arene tetraureas, compounds 47–51 should form homodimeric capsules in H-bond non-competing solvents (e.g

• ]arenes by joining propargyl/2-azidoethyl and p-amino groups on a common platform. Parts of 1H,13C HMBC spectra of calixarenes 12 (a) and 13 (b) recorded in CDCl3 solutions at 600 MHz. Red lines show the key correlations between signals from the calixarene narrow-rim substituents and aromatic units

Design, synthesis and biological evaluation of 2,5-diaryloxazolo[4,5-d]pyrimidin-7-ylamines as selective cytotoxic agents against HeLa cells

• Maryna V. Kachaeva,
• Agnieszka B. Olejniczak,
• Marta Denel-Bobrowska,
• Victor V. Zhirnov,
• Yevheniia S. Velihina,
• Stepan G. Pilyo and
• Volodymyr S. Brovarets

Beilstein J. Org. Chem. 2026, 22, 390–398, doi:10.3762/bjoc.22.27

• Analytique, Université d’Orléans, Pôle de chimierue de Chartres, BP 6759, 45067 Orléans Cedex 2, France 10.3762/bjoc.22.27 Abstract Nine novel functionalized 2,5-diaryloxazolo[4,5-d]pyrimidin-7-ylamines were designed, synthesized and characterized using 1H, 13C NMR, IR spectroscopy, elemental analysis, and

• cyclocondensation products – [1,3]oxazolo[4,5-d]pyrimidines. Subsequent reaction with phosphoryl chloride in the presence of N,N-dimethylaniline converted these intermediates into 2,5-diaryl-7-chloro[1,3]oxazolo[4,5-d]pyrimidines II. The structures of compounds 1–9 were proven and confirmed by 1H and 13C NMR, IR

• were followed by TLC (Silica gel, aluminum sheets 60 F254, Merck). Melting points were recorded on a Fisher-Johns apparatus. 1H and 13C NMR spectra were recorded on a Varian Mercury spectrometer (400 and 101 MHz, respectively) or Bruker Avance DRX 500 spectrometer (500 MHz and 126 MHz, respectively) in

Spirobarbiturates with a pyrrolizidine moiety: synthesis, structure and biological evaluation

• Arthur A. Puzyrkov,
• Andrew S. Drachuk,
• Ekaterina A. Popova,
• Alexander V. Stepakov and
• Vitali M. Boitsov

Beilstein J. Org. Chem. 2026, 22, 274–288, doi:10.3762/bjoc.22.20

• were established using 1H,13C HSQC NMR spectroscopy. The chemical shift values, signal shapes, and spin–spin coupling constants are provided in Table S1 in Supporting Information File 1. The aromatic protons of compounds 4c–e appear in the downfield region of the spectrum. For product 4c, the aromatic

• the diastereotopic H6/H6’ methine protons of different atropisomeric forms. The NH protons of the barbiturate ring resonate as broad singlets at δ 11.5–11.7 ppm, while compound 4a shows an additional broad singlet at δ 11.30 ppm corresponding to the succinimide NH group. In the 13C NMR spectra of endo

• –169.4, 171.2–171.5, 175.5–176.8, and 176.4–177.9 ppm. The spiro carbon appears at δC 70.1–70.3 ppm. For diastereomers 4f–p, the 13C NMR spectra proved more informative than the 1H NMR spectra, clearly displaying a duplicate set of nearly all signals. The chemical shifts of carbons in rings A, B, and C

A mild and atom-efficient four-component cascade strategy for the construction of biologically relevant 4-hydroxyquinolin-2(1H)-one derivatives

• Dmitrii A. Grishin,
• Kseniia I. Sharkovskaia,
• Ilya G. Kolmakov,
• Daria A. Ipatova,
• Rostislav A. Petrov,
• Nikolai D. Dagaev,
• Dmitry A. Skvortsov,
• Maria G. Khrenova,
• Valeriy V. Andreychev,
• Sergei A. Evteev,
• Yan A. Ivanenkov,
• Roman L. Antipin,
• Olga А. Dontsova and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2026, 22, 244–256, doi:10.3762/bjoc.22.18

• well-known topoisomerase II inhibitor doxorubicin (see Supporting Information File 1, page S52), whose toxicity correlates with the cell proliferation rate. Compounds 13b and 13c exhibited non-specific toxicity across all tested cell lines. Antibacterial activities of compounds 9–14 were evaluated in

Configuration–packing synergy enabling integrated crystalline-state RTP and amorphous-state TADF

• Ruiyan Wang and
• Yunan Wu

Beilstein J. Org. Chem. 2026, 22, 224–236, doi:10.3762/bjoc.22.16

• without further purification. Instruments and measurements Low-resolution mass spectra were recorded on a DSQ electron-impact (EI) mass spectrometer. High-resolution mass spectra (HRMS) were acquired on a Thermo MAT95XP instrument using fast atom bombardment (FAB) ionization. 1H and 13C NMR spectra were

• ), 7.30 (d, 2H), 2.37 (s, 3H); 13C NMR (126 MHz, DMSO-d6) δ 167.23, 145.94, 140.78, 140.61, 138.29, 133.75, 133.11, 132.41, 131.58, 131.15, 129.34, 128.56, 127.85, 127.57, 127.08, 126.82, 126.05, 124.56, 123.30, 122.35, 121.02, 120.64, 110.24; EIMS (m/z): [M]+ calcd for C33H22N2O2, 478.1681; found

Synthesis of diaryl phosphates using phytic acid as a phosphorus source

• Kazuya Asao,
• Seika Matsumoto,
• Haruka Mori,
• Riku Yoshimura,
• Takeshi Sasaki,
• Naoya Hirata,
• Yasuyuki Hayakawa and
• Shin-ichi Kawaguchi

Beilstein J. Org. Chem. 2026, 22, 213–223, doi:10.3762/bjoc.22.15

• acid molecule (Figure 6 and Figure S3 in Supporting Information File 1) [57][58][59]. The full 1H, 13C, and 31P NMR spectra are provided in Supporting Information File 1. Next, the extracted phytic acid was used for phosphate synthesis. Although the reaction was conducted under the same conditions as

• File 1. The isolated compounds were characterized via NMR (1H, 13C, 19F, and 31P) and low-resolution mass spectrometry measurements. The NMR measurements were conducted using a Varian NMR 400 MHz system (400 MHz) and a Bruker AVANCE NEO console (400 MHz). Mass spectrometry was performed using LCMS-2020

Streptoquinolines A and B, new antibacterial meroterpenoids produced by Streptomyces sp. TMPU-A0679

• Akiho Yagi,
• Hitomi Tomura,
• Ami Konno and
• Ryuji Uchida

Beilstein J. Org. Chem. 2026, 22, 185–191, doi:10.3762/bjoc.22.12

• and 1620–1680 cm−1 indicated the presence of hydroxy and carbonyl groups, respectively. Streptoquinoline A (1): The molecular formula of 1 was elucidated as C28H35NO6 based on HRESIMS measurements. The 13C NMR spectrum (in DMSO-d6) showed 28 signals, which were classified into five methyl carbons

• III (H-9 (δ 1.58)/H2-11 (δ 2.55, 2.48)). 1H,13C HMBC correlations were then observed from the methyl protons H3-12 (δ 0.89) and H3-13 (δ 0.83) to the sp3 methylene carbon C-3 (δ 41.3), the sp3 quaternary carbon C-4 (δ 32.8), and the sp3 methine carbon C-5 (δ 55.2). Correlations were observed from the

• . Streptoquinoline B (2): The molecular formula of compound 2 was elucidated as C28H35NO6 based on HRESIMS measurements. The 13C NMR and 1H NMR spectra (in DMSO-d6) of compound 2 showed chemical shift values that were almost identical to those of compound 1 (Table 2). Furthermore, 2D NMR experiments revealed similar

Improved synthesis and physicochemical characterization of the selective serotonin 2A receptor agonist 25CN-NBOH

• Adrian G. Rossebø,
• Hannah G. Kolberg,
• Anders E. Tønder,
• Louise Kjaerulff,
• Poul Erik Hansen,
• Karla A. Frydenvang,
• Jesper Østergaard and
• Jesper L. Kristensen

Beilstein J. Org. Chem. 2026, 22, 175–184, doi:10.3762/bjoc.22.11

• isotope effect observable as changes in the 13C NMR chemical shift [18][19]. DFT calculations were based on a truncated model (Figure 6a) containing the essential elements for intramolecular hydrogen bonding. The structure was considered both in vacuum as well as with DMSO or water as implicit solvents

• , in the latter two cases with water molecules hydrogen-bonded to the OH and NH groups. The calculated 13C chemical shift was compared to the experimentally observed values in Supporting Information File 1. A slightly better correlation between the calculated and experimentally observed chemical shift

• was obtained for the structure with two water molecules hydrogen-bonded to the OH and NH groups. The predicted isotope effect was calculated as the difference between the computationally predicted 13C chemical shift for the regular model and for models where each O–H and N–H bond was shortened by 0.01

Design and synthesis of an axially chiral platinum(II) complex and its CPL properties in PMMA matrix

• Daiki Tauchi,
• Sota Ogura,
• Misa Sakura,
• Kazunori Tsubaki and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2026, 22, 143–150, doi:10.3762/bjoc.22.7

• platinum(II) complexes with pincer ligand moieties [12]. Thus, the reaction of S/R-3 with platinum(II) precursor 4 in the presence of CuI and diisopropylamine afforded the target platinum(II) complex S/R-Pt in moderate yield. The identification of the complex S/R-Pt were carried out with 1H and 13C NMR

• optoelectronic applications. Experimental General information All reagents and solvents were of commercial reagent grade and used without further purification. Dichloromethane for spectroscopy was purchased from FUJIFILM Wako Pure Chemical Corporation. All compounds were identified by 1H , 13C NMR and ESI-MS. 1H

• and 13C NMR spectra were recorded on a Bruker Avance III 400 or JEOL JNM-ECZ600R spectrometer at 25 °C in chloroform-d1 or DMSO-d6. 1H NMR chemical shifts are expressed in parts per million (δ) relative to trimethylsilane (TMS) as a reference. Mass spectra were obtained with a Thermo Scientific

Symmetrical D–π–A–π–D indanone dyes: a new design for nonlinear optics and cyanide detection

• Ergin Keleş,
• Alberto Barsella,
• Nurgül Seferoğlu,
• Zeynel Seferoğlu and
• Burcu Aydıner

Beilstein J. Org. Chem. 2026, 22, 131–142, doi:10.3762/bjoc.22.6

• , 13C NMR, and mass spectrometry methods. Dye structures were designed with alkylaminophenyl groups, known for their various electron-donating properties, as donors, and the dicyanovinyl group, with its strong electron-withdrawing properties, as acceptors, conjugated with an indan-2-one core (Figure 1

• method (CM)) (Scheme 1, Table 1). All syntheses were also carried out with microwave irradiation (MWI), which had a short reaction time; however, no improvement in yield was achieved (see Supporting Information File 1). The structural analyses of the compounds were performed using 1H/13C NMR and mass

Highly electrophilic, gem- and spiro-activated trichloromethylnitrocyclopropanes: synthesis and structure

• Ilia A. Pilipenko,
• Mikhail V. Grigoriev,
• Olga Yu. Ozerova,
• Igor A. Litvinov,
• Darya V. Spiridonova,
• Aleksander V. Vasilyev and
• Sergey V. Makarenko

Beilstein J. Org. Chem. 2026, 22, 123–130, doi:10.3762/bjoc.22.5

• conditions. The reaction is carried out either in tetrahydrofuran in the presence of triethylamine or in methanol in the presence of fused potassium acetate. The structures of the isolated individual products were characterized by 1H and 13C NMR, IR spectroscopy, mass spectrometry, and confirmed by single

• Diffraction Research Methods of the A. E. Arbuzov Institute of Organic and Physical Chemistry, the Kazan Scientific Center of the Russian Academy of Sciences. The 1H-13C{1H}, 1H-1H dqfCOSY, 1H-1H NOESY, 1H-13C HMQC, 1H-13C HMBC NMR spectra were recorded on a Jeol ECX400A spectrometer operating at 399.78 MHz

• (1H), 100.53 MHz (13C) in CDCl3 using residual signals of the nondeuterated solvent (δH 7.26, δC 77.16) as the references. The vibrational spectra were measured on a Shimadzu IR-Prestige-21 Fourier-transform IR spectrometer in KBr pellets over 400–4000 cm−1 range (resolution was 2 cm−1). Mass spectra

Reactivity umpolung of the cycloheptatriene core in hexa(methoxycarbonyl)cycloheptatriene

• Dmitry N. Platonov,
• Alexander Yu. Belyy,
• Rinat F. Salikov,
• Kirill S. Erokhin and
• Yury V. Tomilov

Beilstein J. Org. Chem. 2026, 22, 64–70, doi:10.3762/bjoc.22.2

• partial positive charge on the i-positioned carbon atom [36], confirmed by an unusually downfield shifted signal of the CH fragment in the 13C NMR spectrum (δ 160.4 ppm in CD3CN) [21]. Moreover, anion 2 underwent a nucleophilic attack onto the i-position by amines to form fluorescent 5

Sustainable electrochemical synthesis of aliphatic nitro-NNO-azoxy compounds employing ammonium dinitramide and their in vitro evaluation as potential nitric oxide donors and fungicides

• Alexander S. Budnikov,
• Nikita E. Leonov,
• Michael S. Klenov,
• Andrey A. Kulikov,
• Igor B. Krylov,
• Timofey A. Kudryashev,
• Aleksandr M. Churakov,
• Alexander O. Terent’ev and
• Vladimir A. Tartakovsky

Beilstein J. Org. Chem. 2025, 21, 2739–2754, doi:10.3762/bjoc.21.211

• hygroscopic nature. Any manipulations must be carried out by using appropriate standard safety precautions. 1H, 13C, 14N NMR spectra were recorded with Bruker DRX-500 (500.1, 125.8, 36.1 MHz, respectively) and Bruker AV600 (600.1, 150.9, 43.4 MHz, respectively) spectrometers. Chemical shifts are reported in

• delta (δ) units, parts per million (ppm) downfield from internal TMS (1H, 13C) or external CH3NO2 (14N negative values of δN correspond to upfield shifts). The IR spectra were recorded with a Bruker ALPHA-T spectrometer in the range of 400–4000 cm−1 (resolution 2 cm−1) as pellets with KBr or as a thin

• all compounds, XRD of 2c, computational details, and copies of 1H, 13C, 14N, 1H,13C HSQC, and 1H,13C HMBC NMR spectra. Supporting Information File 5: Crystallographic information for compound 2c. Supporting Information File 6: CheckCIF report for the data of 2c. Acknowledgements Crystal structure

Competitive cyclization of ethyl trifluoroacetoacetate and methyl ketones with 1,3-diamino-2-propanol into hydrogenated oxazolo- and pyrimido-condensed pyridones

• Svetlana O. Kushch,
• Marina V. Goryaeva,
• Yanina V. Burgart,
• Marina A. Ezhikova,
• Mikhail I. Kodess,
• Pavel A. Slepukhin,
• Alexandrina S. Volobueva,
• Vladimir V. Zarubaev and
• Victor I. Saloutin

Beilstein J. Org. Chem. 2025, 21, 2716–2729, doi:10.3762/bjoc.21.209

• , causes the formation of two to four diastereomers, the structure of which has been determined with 1H, 19F, 13C, 2D 1H-13C HSQC/HMBC, 1H-1H COSY/NOESY NMR and X-ray diffraction analysis. Keywords: condensed pyridones; 1,3-diamino-2-propanol; ethyl 4,4,4-trifluoroacetoacetate; methyl ketones; three

• octahydropyrido[1,2-a]pyrimidinones 4a–d and hexahydrooxazolo[3,2-a]pyridones 5a–c was determined by IR, 1H, 19F, 13C NMR spectroscopy, two-dimensional NMR experiments, and X-ray diffraction analysis (XRD). The IR spectra of octahydropyrido[1,2-a]pyrimidinones 4a–d are characterized by reduced vibrational

• crystal 4a–d and 5a–c are in excellent agreement with the results of 1D and 2D NMR studies, enabling us to extend these structural assignments to other synthesized bicycles. The complete assignment of signals in 1H and 13C NMR spectra was performed using two-dimensional 1H-1H COSY, NOESY and 1H-13C HSQC

Tandem hydrothiocyanation/cyclization of CF₃-iminopropargyl alcohols with NaSCN in the presence of AcOH

• Ruslan S. Shulgin,
• Ol’ga G. Volostnykh,
• Anton V. Stepanov,
• Igor’ A. Ushakov,
• Alexander V. Vashchenko and
• Olesya A. Shemyakina

Beilstein J. Org. Chem. 2025, 21, 2694–2702, doi:10.3762/bjoc.21.207

• available starting materials were used without further purification. CF3/n-C3F7-substituted iminopropargyl alcohols 1 were prepared according to published methods [31][32]. The structures of synthesized products have been proven by 1H, 13C and 2D (1Н,13С HMBC) NMR, 19F NMR techniques, as well as IR spectra

Synthesis of new tetra- and pentacyclic, methylenedioxy- and ethylenedioxy-substituted derivatives of the dibenzo[c,f][1,2]thiazepine ring system

• Gábor Berecz,
• András Dancsó,
• Mária Tóthné Lauritz,
• Loránd Kiss,
• Gyula Simig and
• Balázs Volk

Beilstein J. Org. Chem. 2025, 21, 2645–2656, doi:10.3762/bjoc.21.205

• standard open 40 μL aluminum pan under 50 mL/min nitrogen atmosphere. IR spectra were obtained on a Bruker ALPHA FT-IR spectrometer in KBr pellets or in neat. NMR spectra were recorded at 295 K on a Bruker Avance III HD 600 (600 and 150 MHz for 1H and 13C NMR spectra, respectively) spectrometer equipped

• with a Prodigy cryo-probehead or a Varian Unity Inova 500 (500 and 125 MHz for 1H and 13C NMR spectra, respectively), or a Varian Unity Inova 400 (400 and 100 MHz for 1H and 13C NMR spectra, respectively), or a Varian Gemini 200 (200 and 50 MHz for 1H and 13C NMR spectra, respectively) spectrometer

• . The pulse programs were taken from the Bruker software library (TopSpin 3.5) and full 1H and 13C assignments were achieved with widely accepted strategies. 1H assignments were accomplished using general knowledge of chemical shift dispersion with the aid of the 1H–1H coupling pattern. CDCl3 or DMSO-d6

Thiazolidinones: novel insights from microwave synthesis, computational studies, and potentially bioactive hybrids

• Luan A. Martinho,
• Victor H. J. G. Praciano,
• Guilherme D. R. Matos,
• Claudia C. Gatto and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2025, 21, 2618–2636, doi:10.3762/bjoc.21.203

• compounds 3n and 4n was carried out using torsion angle analysis and 13C NMR chemical shift calculations to evaluate the absence of expected signals in the NMR spectra of these compounds. Their photophysical properties were also assessed, confirming a preference for a fluorescence mechanism via an ICT

• efficient synthesis of eight novel imidazo[1,2-a]pyridine–thiazolidinone hybrids in high yields (up to 99%). A spectroscopic analysis of selected compounds was carried out, including torsion angle evaluation and 13C NMR chemical shift calculations, justifying the absence of expected signals in some cases

• scans) and 151 MHz for 13C NMR (20,480 scans), using an overnight experiment in DMSO-d6 at a concentration of 0.1 M. Specifically, the spectra showed either an absence of expected signals or a lack of signal multiplicity, which was apparent in both the 1H NMR and, more prominently, in the 13C NMR