Asymmetric Mannich reaction of aromatic imines with malonates in the presence of multifunctional catalysts

• Kadri Kriis,
• Harry Martõnov,
• Annette Miller,
• Mia Peterson,
• Ivar Järving and
• Tõnis Kanger

Beilstein J. Org. Chem. 2026, 22, 151–157, doi:10.3762/bjoc.22.8

• 20: Experimental procedures, synthetic details, NMR spectra, chiral HPLC chromatograms. Funding The research was funded by the Estonian Ministry of Education and Research (grant No. PRG1031).

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

• 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

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

• use of method E in the reaction of 1-bromo-1-nitro-3,3,3-trichloropropene (1) with methyl cyanoacetate, ethyl cyanoacetate or benzoylacetonitrile makes it possible to obtain cyclopropanes 3–5 in the yields up to 72% (Scheme 2). They are formed as single diastereomers (according to the 1H NMR spectra

• 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

• the structure are shown in Table S1 in Supporting Information File 1. Supporting Information File 14: General synthetic procedures, characterization data and copies of IR spectra, 1H-13C{1H}, 1H-1H dqfCOSY, 1H-1H NOESY, 1H-13C HMQC, 1H-13C HMBC NMR spectra of all synthesized compounds, and

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

• , quantum chemical calculation details and copies of NMR spectra. Funding This work was financially supported by the Russian Science Foundation (Grant No. 25-23-00616).

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

• 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

• –1628 cm−1 and NH2 groups at ν 3376–3272 cm−1. The structures of the obtained heterocycles 4 and 5 contain three stereocenters, so one could expect the formation of up to 8 stereoisomers in each case. Analysis of the 19F NMR spectra showed that from two to four diastereomers of

• 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

• , whereas in the trans-configuration of the hexahydropyrimidine ring, a cross-peak (OHax, H(2)eq) appears in the spectrum. In the 1H NMR spectra of octahydropyrido[1,2-a]pyrimidinones 4att, 4a–dct, which have the trans-configuration of the hexahydropyrimidine ring, the signal of the H(3) proton has the form

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

• formation and ratio of the products in contrast to the substituents in the imine fragment. NMR monitoring of reactions (1a/NaSCN/AcOH or 1g/NaSCN/AcOH in MeCN) did not allow to detect any intermediates even when the temperature was lowered to 0 °C. In the 1H and 19F NMR spectra the signals of products 2a

• and 3a appeared immediately upon mixing the starting reagents (Figure 1a and b). This indicated that the cyclization occurred almost immediately. Moreover, in the NMR spectra of the 1g/NaSCN/AcOH reaction mixture in MeCN we detected signals assigned to isothiozolium salt 2g (1H NMR: δ 8.30 s (CH

• operational simplicity, relatively mild conditions and readily prepared starting materials. Experimental General information. 1Н, 13С {1H}, and 19F NMR spectra were recorded on a Bruker DPX-400 spectrometer (400.1, 100.6, and 376 MHz, respectively) in CDCl3 and (CD3)2CO using hexamethyldisiloxane (HMDS) as

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

• was used as the solvent and tetramethylsilane (TMS) as the internal standard. Chemical shifts (δ) and coupling constants (J) are given in ppm and in Hz, respectively. Coupling constants reported in the 1H NMR spectra are H–H couplings unless otherwise stated (J ≡ JH–H). Three-bond H–H couplings (3J

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

• and 4n During the characterization of the compounds obtained in our study to determine the reaction scope, an anomaly was observed in the NMR spectra of products 3n and 4n derived from 4-diethylaminobenzaldehyde (see Supporting Information File 1). The spectra were acquired at 600 MHz for 1H NMR (320

• interactions are observed in both compounds forming dimer-like structures. The compounds show hydrogen bonds between N1–H1···O1’ with a distance of 2.06 Å in 3n (Figure 4b) and 1.98 Å in 4n (Figure S250b in Supporting Information File 1). The anomaly observed in the NMR spectra may be attributed to

Silica gel with covalently attached bambusuril macrocycle for dicyanoaurate sorption from water

• Michaela Šusterová and
• Vladimír Šindelář

Beilstein J. Org. Chem. 2025, 21, 2604–2611, doi:10.3762/bjoc.21.201

• carried out in nitrogen atmosphere. The dicyanoaurate concentration in solution was determined according to UV–vis spectra recorded with a CARY 60 spectrophotometer (Agilent Technologies). NMR spectra were recorded on a Bruker Avance III 300 spectrometer (300.15 Hz, 298.15 K). Preparation of SG-NHCO-BU1

Ni-promoted reductive cyclization cascade enables a total synthesis of (+)-aglacin B

• Si-Chen Yao,
• Jing-Si Cao,
• Jian Xiao,
• Ya-Wen Wang and
• Yu Peng

Beilstein J. Org. Chem. 2025, 21, 2548–2552, doi:10.3762/bjoc.21.197

• structures of aglacins A, B, C, and E. Retrosynthetic analysis of (+)-aglacin B (2). Synthesis of cyclization precursor 5. Synthesis of (+)-aglacin B (2). Supporting Information Supporting Information File 16: Experimental procedures, characterization data, and copies of 1H/13C NMR spectra

Synthesis and characterization of a isothiouronium-calix[4]arene derivative: self-assembly and anticancer activity

• Giuseppe Granata,
• Loredana Ferreri,
• Claudia Giovanna Leotta,
• Giovanni Mario Pitari and
• Grazia Maria Letizia Consoli

Beilstein J. Org. Chem. 2025, 21, 2535–2541, doi:10.3762/bjoc.21.195

• precipitate was recovered by filtration and washed several times with ethyl ether, to give pure compound 3 (118 mg, 96% yield). Characterization of compound 3: NMR spectra were acquired on a Bruker Avance 400TM spectrometer. Chemical shifts (δ, ppm) are reported referring to the residual peak of the solvent

Pentacyclic aromatic heterocycles from Pd-catalyzed annulation of 1,5-diaryl-1,2,3-triazoles

• Kaylen D. Lathrum,
• Emily M. Hanneken,
• Katelyn R. Grzelak and
• James T. Fletcher

Beilstein J. Org. Chem. 2025, 21, 2524–2534, doi:10.3762/bjoc.21.194

• Supporting Information Supporting Information File 4: Description of materials, experimental methods, synthetic procedures, analytical characterization and copies of NMR spectra for novel compounds. Funding Research reported in this publication was supported by the National Institute of General Medical

Effect of a photoswitchable rotaxane on membrane permeabilization across lipid compositions

• Udyogi N. K. Conthagamage,
• Lilia Lopez,
• Zuliah A. Abdulsalam and
• Víctor García-López

Beilstein J. Org. Chem. 2025, 21, 2498–2512, doi:10.3762/bjoc.21.192

• the compounds, while chloroform was used for cholesterol and lipid stock solutions. 1H NMR spectra were recorded using Bruker AV III 400 and Bruker AV III 500 spectrometers. 13C NMR was conducted on a Bruker AV III 500 spectrometer. All chemical shifts (δ) are reported in ppm, referencing residual non

Assembly strategy for thieno[3,2-b]thiophenes via a disulfide intermediate derived from 3-nitrothiophene-2,5-dicarboxylate

• Roman A. Irgashev

Beilstein J. Org. Chem. 2025, 21, 2489–2497, doi:10.3762/bjoc.21.191

• -nucleophiles to form sulfide 2 and disulfide 3. Optimization of the reaction conditions for the reduction–alkylation of disulfide 3. Supporting Information Supporting Information File 12: Full experimental details, characterization data, copies of NMR spectra and HRMS for all new compounds. Acknowledgements

Palladium-catalyzed regioselective C1-selective nitration of carbazoles

• Vikash Kumar,
• Jyothis Dharaniyedath,
• Aiswarya T P,
• Sk Ariyan,
• Chitrothu Venkatesh and
• Parthasarathy Gandeepan

Beilstein J. Org. Chem. 2025, 21, 2479–2488, doi:10.3762/bjoc.21.190

• of our method. Key mechanistic studies. Optimization studies.a Supporting Information Supporting Information File 9: Experiment details, characterization data, copy of NMR spectra of synthesized compounds, and single-crystal X-ray diffraction data. Supporting Information File 10: CIF file for 2a

Synthesis of the tetracyclic skeleton of Aspidosperma alkaloids via PET-initiated cationic radical-derived interrupted [2 + 2]/retro-Mannich reaction

• Ru-Dong Liu,
• Jian-Yu Long,
• Zhi-Lin Song,
• Zhen Yang and
• Zhong-Chao Zhang

Beilstein J. Org. Chem. 2025, 21, 2470–2478, doi:10.3762/bjoc.21.189

• along IRC path. e) Spin-density analyses of R-24 and F-10 (isovalue = 0.004). f) NBO analyses of the selected transient structures (isovalue = 0.04). Substrate scope. Conditions screening.a Supporting Information Supporting Information File 6: Experimental procedures, characterization data, NMR spectra

The high potential of methyl laurate as a recyclable competitor to conventional toxic solvents in [3 + 2] cycloaddition reactions

• Ayhan Yıldırım and
• Mustafa Göker

Beilstein J. Org. Chem. 2025, 21, 2389–2415, doi:10.3762/bjoc.21.184

• transition state (Scheme 2). Meanwhile, the diastereomeric ratio of interest can be determined by integrating the 1H NMR spectra, in particular by selecting the appropriate signal pairs (one from each diastereomer) belonging to the respective cycloaddition product. An example of these selected protons (trans

• in Table 1, entry 9. As illustrated in Table 5, the product yields obtained from the reactions are presented alongside the observed cis/trans diastereoisomer ratios in the presence of the respective catalysts. However, upon examination of the 1H NMR spectra of compound 3a synthesized in the presence

• performed using silica gel (60 F254, Merck, Darmstadt, Germany) plates. Melting points were recorded using a Büchi melting point B-540 apparatus (Büchi Labortechnik AG in Flawil, Switzerland). The IR spectra were measured by Spectrum Two FT-IR spectrometer (PerkinElmer, Massachusetts, USA). The NMR spectra

An Fe(II)-catalyzed synthesis of spiro[indoline-3,2'-pyrrolidine] derivatives

• Elizaveta V. Gradova,
• Nikita A. Ozhegov,
• Roman O. Shcherbakov,
• Alexander G. Tkachenko,
• Larisa Y. Nesterova,
• Elena Y. Mendogralo and
• Maxim G. Uchuskin

Beilstein J. Org. Chem. 2025, 21, 2383–2388, doi:10.3762/bjoc.21.183

• mmol scale experiment. The scope of the Fe-catalyzed spirocyclization. aIsolated yield of the 4.2 mmol scale experiment. The proposed mechanism of product 4 formation. Supporting Information Supporting Information File 2: General reaction procedures, compound characterization data, and copies of NMR

• spectra. Acknowledgements We are grateful to the associate professor of Microbiology and Virology Dept., leading researcher of Central Research Laboratory of E. A. Vagner Perm State Medical University (Perm, Russian Federation) Godovalov A. P. for providing the clinical strains. Funding We acknowledge

Synthetic study toward vibralactone

• Liang Shi,
• Jiayi Song,
• Yiqing Li,
• Jia-Chen Li,
• Shuqi Li,
• Li Ren,
• Zhi-Yun Liu and
• Hong-Dong Hao

Beilstein J. Org. Chem. 2025, 21, 2376–2382, doi:10.3762/bjoc.21.182

• . Supporting Information Supporting Information File 34: Characterization data and 1H NMR, 13C NMR spectra of the compounds. Acknowledgements The authors sincerely acknowledge all of the anonymous reviewers for their valuable comments and suggestions. Funding We are grateful for financial support from the Qin

Conformational effects on iodide binding: a comparative study of flexible and rigid carbazole macrocyclic analogs

• Guang-Wei Zhang,
• Yong Zhang,
• Le Shi,
• Chuang Gao,
• Hong-Yu Li and
• Lei Xue

Beilstein J. Org. Chem. 2025, 21, 2369–2375, doi:10.3762/bjoc.21.181

• successfully obtained. This indirectly confirmed the molecular structure of WDG [22]. The NH protons of the carbazole moiety in PBG and WDG were observed as singlets at δ 7.9706 and δ 7.8624, respectively, in their 1H NMR spectra (Figure 1a and 1b). In order to study the role and mechanism of anion recognition

• spectroscopy. Results and Discussion Partial 1H NMR spectra of PBG and WDG after binding to tetrabutylammonium iodide (TBAI) are presented in Figure 2a and 2b, respectively. All 1H NMR titrations were conducted at a fixed concentration of 8.7 mM. With the addition of 2 equivalents TBAI, the NH peak on the PBG

• , which provides a foundation for developing next-generation smart sensors with programmable anion selectivity. (a) partial 1H NMR spectrum of PBG in CDCl3 (400 MHz, CDCl3, 25 °C), (b) Partial 1H NMR spectrum of WDG in CDCl3 (400 MHz, CDCl3, 25 °C). (a) Partial 1H NMR spectra of PBG and TBAI at different

Insoluble methylene-bridged glycoluril dimers as sequestrants for dyes

• Suvenika Perera,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 2302–2314, doi:10.3762/bjoc.21.176

• accord with the depicted C2v-symmetric structures. Figure 3 shows the 1H NMR spectra recorded for G2W1–G2W4 in DMSO-d6 at 400 MHz. As expected, all four hosts display two singlets for the equatorial CH3 groups (a, b), two pairs of doublets for the diastereotopic CH2 groups (c,c’ and d,d’) in the expected

• and were used without further purification. H2 was synthesized according to a previously published procedure [39]. NMR spectra were measured on commercial spectrophotometers at 400 MHz for 1H and 100 MHz for 13C in trifluoroacetic acid with a capillary tube containing deuterated water (D2O) for

• study. 1H NMR spectra recorded (400 MHz, DMSO-d6, rt) for: a) G2W1, b) G2W2, c) G2W3, d) G2W4. Plot of removal efficiency of dyes from water after incubating with equimolar amounts (7.2 μmol) of H2 (5.0 mg), G2W1 (9.0 mg), G2W2 (7.2 mg), G2W3 (5.7 mg), and G2W4 (5.0 mg) for 1 hour at 25 °C as determined

Research towards selective inhibition of the CLK3 kinase

• Vinay Kumar Singh,
• Frédéric Justaud,
• Dabbugoddu Brahmaiah,
• Nangunoori Sampath Kumar,
• Blandine Baratte,
• Thomas Robert,
• Stéphane Bach,
• Chada Raji Reddy,
• Nicolas Levoin and
• René L. Grée

Beilstein J. Org. Chem. 2025, 21, 2250–2259, doi:10.3762/bjoc.21.172

• Supporting Information Supporting Information File 26: Detailed experimental procedures and spectral data, kinase inhibition studies, molecular modelling studies, analysis of dose-dependent effect of VS-77 on the kinase activity of Mm_CLKs and copies of the 1H and 13C NMR spectra. Acknowledgements We thank

A chiral LC–MS strategy for stereochemical assignment of natural products sharing a 3-methylpent-4-en-2-ol moiety in their terminal structures

• Rei Suo,
• Raku Irie,
• Hinako Nakayama,
• Yuta Ishimaru,
• Yuya Akama,
• Masato Oikawa and
• Shiro Itoi

Beilstein J. Org. Chem. 2025, 21, 2243–2249, doi:10.3762/bjoc.21.171

• fragment (7) from capsulactone (1). Synthesis of 4-methoxy-3-methyl-4-oxobutan-2-yl 4-nitrobenzoates (2S,3S)-8, (2S,3R)-9, (2R,3R)-10, and (2R,3S)-11. Supporting Information Supporting Information File 24: Experimental section, LC–MS chromatograms and NMR spectra. Funding This work was financially

Pd-catalyzed dehydrogenative arylation of arylhydrazines to access non-symmetric azobenzenes, including tetra-ortho derivatives

• Loris Geminiani,
• Kathrin Junge,
• Matthias Beller and
• Jean-François Soulé

Beilstein J. Org. Chem. 2025, 21, 2234–2242, doi:10.3762/bjoc.21.170

• from phenylhydrazine and aryl bromides. The gray box provides a detailed list of all identified side-products. Supporting Information Supporting Information File 20: Details of optimization experiments, full characterization data, and NMR spectra (1H, 13C, 19F) for all products. Funding L.G