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

Thiadiazino-indole, thiadiazino-carbazole and benzothiadiazino-carbazole dioxides: synthesis, physicochemical and early ADME characterization of representatives of new tri-, tetra- and pentacyclic ring systems and their intermediates

• Gyöngyvér Pusztai,
• László Poszávácz,
• Anna Vincze,
• András Marton,
• Ahmed Qasim Abdulhussein,
• Judit Halász,
• András Dancsó,
• Gyula Simig,
• György Tibor Balogh and
• Balázs Volk

Beilstein J. Org. Chem. 2025, 21, 2220–2233, doi:10.3762/bjoc.21.169

• on a Bruker ALPHA FT-IR spectrometer in KBr pellets, ν̃ was reported in cm−1. 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-probe head. Full 1H and 13C assignments were achieved

A m-quaterphenyl probe for absolute configurational assignments of primary and secondary amines

• Yuka Takeuchi,
• Mutsumi Kobayashi,
• Yuuka Gotoh,
• Mari Ikeda,
• Yoichi Habata,
• Tomohiko Shirai and
• Shunsuke Kuwahara

Beilstein J. Org. Chem. 2025, 21, 2211–2219, doi:10.3762/bjoc.21.168

• used without further purification. Melting points were obtained with a Mel-Temp capillary apparatus and were not corrected. IR spectra were obtained as KBr disks on a JASCO FT/IR-410 spectrophotometer. The FAB mass spectra were recorded using a JEOL 600H mass spectrometer. 1H and 13C{1H} NMR spectra

• central biphenyl moiety rotates freely, forming an equilibrium mixture of P and M conformers. Supporting Information Supporting Information File 9: Experimental procedures, characterization data including copies of NMR spectra (1H NMR, 13C NMR), CD spectra of (S)-2f and (R)-2f, theoretical calculations

Synthesis of triazolo- and tetrazolo-fused 1,4-benzodiazepines via one-pot Ugi–azide and Cu-free click reactions

• Xiaoming Ma,
• Zijie Gao,
• Jiawei Niu,
• Wentao Shao,
• Shenghu Yan,
• Sai Zhang and
• Wei Zhang

Beilstein J. Org. Chem. 2025, 21, 2202–2210, doi:10.3762/bjoc.21.167

• 1H NMR spectra are different (Figure 2). The most evident differences are the disappearance of the signal for the alkyne H at 2.36 ppm in the spectrum of 6a and the appearance of a peak at 8.14 ppm for the proton on the triazole ring of 8a. The aromatic protons in 8a show two distinct doublets and

• 7a–k in 36–90% yields, 8a–g in 77–92% yields. Note: When 2-yn-1-amine hydrochlorides 2b–e were employed in this one-pot reaction, Et3N (0.3 mol, 1.5 equiv) was added into the vessel at the initial stage. Some bioactive molecules bearing triazole, tetrazole, and 1,4-benzodiazepin rings. 1H NMR spectra

Further elaboration of the stereodivergent approach to chaetominine-type alkaloids: synthesis of the reported structures of aspera chaetominines A and B and revised structure of aspera chaetominine B

• Jin-Fang Lü,
• Jiang-Feng Wu,
• Jian-Liang Ye and
• Pei-Qiang Huang

Beilstein J. Org. Chem. 2025, 21, 2072–2081, doi:10.3762/bjoc.21.162

• 1H and 13C NMR are methanol-d4 that is different from Tan’s work [21] who used DMSO-d6 to record 1H and 13C NMR spectra of (–)-chaetominine (1). Thus we undertook the synthesis of the proposed structures of aspera chaetominines A (12) and B (13). By adopting our first-generation strategy [57][58][61

• incorrect. It is worth noting that compound 12 has been obtained in our previous investigation [65]. However, the 1H and 13C NMR spectra were recorded in DMSO-d6 which prevent a direct comparison with the data of aspera chaetominine A. We next addressed the synthesis of aspera chaetominine B (13). Employing

• (–)-isochaetominine C (6), whose absolute configuration is tentatively assigned as 2R,3R,11S,14R. It is worth noting that compound 13 has been obtained in our previous investigation [63]. However, the 1H and 13C NMR spectra were recorded in DMSO-d6 which prevent a direct comparison with the data of aspera

Switchable pathways of multicomponent heterocyclizations of 5-amino-1,2,4-triazoles with salicylaldehydes and pyruvic acid

• Yana I. Sakhno,
• Oleksander V. Buravov,
• Kostyantyn Yu. Yurkov,
• Anastasia Yu. Andryushchenko,
• Svitlana V. Shishkina and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2025, 21, 2030–2035, doi:10.3762/bjoc.21.158

• control of the reaction, while oxygen-bridged heterocycles 4 are formed under thermodynamic control. The purity and structure of compounds 4 and 5 were established by elemental analysis, mass spectrometry, 1H and 13C NMR spectroscopy, and X-ray diffraction study (Figure 1). For example, the 1H NMR spectra

• characterized by the following signals in the 1H NMR spectra: a proton singlet of the pyrimidine NH group at 8.30–8.31 ppm, a multiplet of aromatic protons in the region of 6.95–7.51 ppm, a proton multiplet of the CH group at 4.65–4.68 ppm and singlet for protons for the triazole CH3O group at 3.7 ppm. The 1H

• NMR spectra of heterocyclic acids 5a–c exhibited a broad singlet of proton of the carboxyl group at 11.88–14.02 ppm, a singlet of proton of the hydroxy group at 9.41–9.86 ppm, a singlet of proton of the pyrimidine NH group at 7.72–7.91 ppm, a singlet of proton of the triazolylamine NH group at 7.44

α-Ketoglutaric acid in Ugi reactions and Ugi/aza-Wittig tandem reactions

• Vladyslav O. Honcharov,
• Yana I. Sakhno,
• Olena H. Shvets,
• Vyacheslav E. Saraev,
• Svitlana V. Shishkina,
• Tetyana V. Shcherbakova and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2025, 21, 2021–2029, doi:10.3762/bjoc.21.157

• and 13C NMR spectroscopy, and by X-ray diffraction study (see Experimental part). The 1H NMR spectra of compounds 5 are characterized by the following signals: a broad carboxyl group proton singlet at 12.10–12.17 ppm, an NH group proton singlet at 7.74–8.02 ppm, an aromatic protons multiplet at 6.52

• compared to compounds 5, which can be clearly seen in the spectrum of compound 8h with both substituted ortho-positions of the amine moiety. In our opinion, this indicates the presence of rotamerism [59][60] caused by the restricted rotation of the sterically hindered amide group. The 1H NMR spectra of

• the 1H NMR spectra of quinoxalinones 9, a shift of the methylene groups signal to a weaker field (2.90–3.14 ppm and 2.63–2.77 ppm) is observed in comparison to compounds 8 (2.60–3.06 ppm and 2.14–2.35 ppm). Furthermore, comparison of the 13C NMR spectra of compounds 8 and 9 shows a characteristic

Aryl iodane-induced cascade arylation–1,2-silyl shift–heterocyclization of propargylsilanes under copper catalysis

• Rasma Kroņkalne,
• Rūdolfs Beļaunieks,
• Armands Sebris,
• Anatoly Mishnev and
• Māris Turks

Beilstein J. Org. Chem. 2025, 21, 1984–1994, doi:10.3762/bjoc.21.154

• NMR spectra. Interestingly, the internal alkyne 7c (R = Ph, Si = TIPS) was completely unreactive under both standard arylation conditions (70 °C in EtOAc) and higher reaction temperatures (110 °C in BuOAc). In these cases, the starting material was recovered with no signs of degradation. This

• . Conditions screening for copper-catalyzed arylation–cyclization of propargylsilane 7d. Supporting Information Supporting Information File 4: Experimental data, synthesis procedures, 1H and 13C NMR spectra, and X-ray data. Funding This work was supported by the Latvian Council of Science Grant LZP-2023/1

Photochemical reduction of acylimidazolium salts

• Michael Jakob,
• Nick Bechler,
• Hassan Abdelwahab,
• Fabian Weber,
• Janos Wasternack,
• Leonardo Kleebauer,
• Jan P. Götze and
• Matthew N. Hopkinson

Beilstein J. Org. Chem. 2025, 21, 1973–1983, doi:10.3762/bjoc.21.153

• ) step to form the zwitterionic alkoxide E and the oxidized DIPEA iminium ion F. Notably, small signals consistent with trace amounts of the alkoxide species E were occasionally detected in the crude 1H NMR spectra of reactions conducted both in the presence and absence of a photocatalyst (see Supporting

• -mediated reduction developed above. Performing the same reaction with a selection of electronically diverse derivatives of 1 bearing 4-CF3 (6), 4-CO2Me (7) and 4-OMe (8) groups also resulted in the formation of reduced products with 1H NMR spectra consistent with O-silylated species (1H NMR yields: from 6

• : Experimental procedures, characterization data of all isolated products, details of UV–vis, time-course and computational studies as well as copies of NMR spectra for novel compounds. Acknowledgements We thank Prof. Dr. Beate Koksch and the AG Koksch (FU Berlin) for supervisory assistance and helpful