On the aromaticity and photophysics of 1-arylbenzo[a]imidazo[5,1,2-cd]indolizines as bicolor fluorescent molecules for barium tagging in the study of double-beta decay of ¹³⁶Xe

• Eric Iván Velazco-Cabral,
• Fernando Auria-Luna,
• Juan Molina-Canteras,
• Miguel A. Vázquez,
• Iván Rivilla and
• Fernando P. Cossío

Beilstein J. Org. Chem. 2025, 21, 1627–1638, doi:10.3762/bjoc.21.126

• of the universe [4] is 13.8·109 years. However, characterization of the neutrino as a Majorana particle constitutes a formidable challenge that would have an extraordinary impact in cosmology since this would contribute decisively to explain why our universe is formed by matter and not antimatter [5

3-Aryl-2H-azirines as annulation reagents in the Ni(II)-catalyzed synthesis of 1H-benzo[4,5]thieno[3,2-b]pyrroles

• Julia I. Pavlenko,
• Pavel A. Sakharov,
• Anastasiya V. Agafonova,
• Derenik A. Isadzhanyan,
• Alexander F. Khlebnikov and
• Mikhail S. Novikov

Beilstein J. Org. Chem. 2025, 21, 1595–1602, doi:10.3762/bjoc.21.123

• charge by the joint Cambridge Crystallographic Data Centre. Supporting Information File 24: Full experimental details, characterization data and copies of NMR spectra for all new compounds. Acknowledgements This research was carried out using resources of the Centre for Magnetic Resonance, the Research

Thermodynamic equilibrium between locally excited and charge transfer states in perylene–phenothiazine dyads

• Issei Fukunaga,
• Shunsuke Kobashi,
• Yuki Nagai,
• Hiroki Horita,
• Hiromitsu Maeda and
• Yoichi Kobayashi

Beilstein J. Org. Chem. 2025, 21, 1577–1586, doi:10.3762/bjoc.21.121

• structural characterization A series of π-orthogonal D–A molecules based on the Pe–PTZ framework were synthesized to systematically modulate the electronic properties and spatial arrangement between the donor and acceptor units. Structural features were designed to ensure orthogonality between the Pe and PTZ

• : Experimental and computational details, synthesis and characterization of compounds, additional spectroscopic results, and theoretical calculations. Acknowledgements The authors acknowledge Dr. Tatsuo Nakagawa, UNISOKU Co., Ltd., for nanosecond transient absorption measurements Funding This work was supported

Synthesis of an aza[5]helicene-incorporated macrocyclic heteroarene via oxidation of an o-phenylene-pyrrole-thiophene icosamer

• Yusuke Matsuo,
• Aoi Nakagawa,
• Shu Seki and
• Takayuki Tanaka

Beilstein J. Org. Chem. 2025, 21, 1561–1567, doi:10.3762/bjoc.21.119

• an aza[5]helicene-incorporated macrocycle. The resulting cyclophane-like structure and its optical properties have been analyzed in detail. Results and Discussion Synthesis and characterization Synthesis We obtained o-phenylene-pyrrole-thiophene hybrid icosamer 4 during our attempt to synthesize

• primarily localized on the aza[5]helicene moieties, while the orbital coefficients are distributed to the bridging thiophene and o-phenylene units in LUMO, indicating a charge-transfer (CT)-like transition. However, further optical characterization of compound 5 was limited due to its poor solubility in

• heteroarene 5. Supporting Information Supporting Information File 14: Experimental procedures, characterization data of all products, copies of 1H and 13C NMR spectra, optical data, and DFT calculation results. Supporting Information File 15: Crystallographic Information File for compound 4. Supporting

Facile synthesis of hydantoin/1,2,4-oxadiazoline spiro-compounds via 1,3-dipolar cycloaddition of nitrile oxides to 5-iminohydantoins

• Juliana V. Petrova,
• Varvara T. Tkachenko,
• Victor A. Tafeenko,
• Anna S. Pestretsova,
• Vadim S. Pokrovsky,
• Maxim E. Kukushkin and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2025, 21, 1552–1560, doi:10.3762/bjoc.21.118

• technique. Supporting Information Supporting Information File 10: Detailed experimental procedures, characterization data and X-ray crystallographic details. Funding The synthetic research was funded by the Russian Science Foundation, grant number 24-23-00173. Сell viability tests were supported by the

Azide–alkyne cycloaddition (click) reaction in biomass-derived solvent Cyrene^TM under one-pot conditions

• Zoltán Medgyesi and
• László T. Mika

Beilstein J. Org. Chem. 2025, 21, 1544–1551, doi:10.3762/bjoc.21.117

• synthesis of benzyl azide, detailed experimental procedures, and characterization of prepared compounds are reported in Supporting Information File 1. General procedure for click reaction in CyreneTM In a 4 mL screw-cap vial, 1.15 mmol of benzyl azide (1a), 1 mmol corresponding acetylene, 0.1 equiv Et3N

• constant weight under the fume hood. The detailed experimental procedure, as well as the characterization of isolated compounds, are provided in Supporting Information File 1. General procedure for click reaction in CyreneTM under one-pot conditions In a 4 mL screw-cap vial, 1.15 mmol of corresponding

• work-up procedure is similar to the one given above. The detailed experimental procedure, as well as the characterization of isolated compounds, are provided in Supporting Information File 1. Comparison of various solvents used in the CuAAC reaction. Reaction conditions: 1.15 mmol benzyl azide, 1 mmol

General method for the synthesis of enaminones via photocatalysis

• Paula Pérez-Ramos,
• Raquel G. Soengas and
• Humberto Rodríguez-Solla

Beilstein J. Org. Chem. 2025, 21, 1535–1543, doi:10.3762/bjoc.21.116

• : Additional optimization details, mechanistic studies, experimental details, characterization data and NMR spectra for enaminones 9. Acknowledgements We would like to thank Prof. Jose Manuel Costa-Fernández for his help with the spectroscopic studies. Funding This work has received financial support from MCI

Azobenzene protonation as a tool for temperature sensing

• Antti Siiskonen,
• Sami Vesamäki and
• Arri Priimagi

Beilstein J. Org. Chem. 2025, 21, 1528–1534, doi:10.3762/bjoc.21.115

• acetonitrile (MeCN). Supporting Information Supporting Information File 4: Reaction schemes and characterization, UV–vis absorption spectra, determination of the stoichiometry, determination of thermodynamic parameters for 3H+MSA−MSA, molecular orbitals, calculated absorption spectra and geometry-optimized

Calcium waste as a catalyst in the transesterification for demanding esters: scalability perspective

• Anton N. Potorochenko and
• Konstantin S. Rodygin

Beilstein J. Org. Chem. 2025, 21, 1520–1527, doi:10.3762/bjoc.21.114

• . Reaction conditions: oil to alcohol molar ratio = 1:12, 1 wt % CS600, 65 °C, 2 h. Control experiments on the example of transesterification of soybean oil with methanol.a Supporting Information Supporting Information File 2: General information, experimental procedures, characterization data, and copies

Photoredox-catalyzed arylation of isonitriles by diaryliodonium salts towards benzamides

• Nadezhda M. Metalnikova,
• Nikita S. Antonkin,
• Tuan K. Nguyen,
• Natalia S. Soldatova,
• Alexander V. Nyuchev,
• Mikhail A. Kinzhalov and
• Pavel S. Postnikov

Beilstein J. Org. Chem. 2025, 21, 1480–1488, doi:10.3762/bjoc.21.110

• using 1,2-dibromoethane as an internal standard. cNot detected by GC–MS. Proposed reaction mechanism. Optimization of the reaction conditions.a Supporting Information Supporting Information File 32: Experimental section, characterization data and control experiments. Acknowledgements Authors

Microwave-enhanced additive-free C–H amination of benzoxazoles catalysed by supported copper

• Andrei Paraschiv,
• Valentina Maruzzo,
• Filippo Pettazzi,
• Stefano Magliocco,
• Paolo Inaudi,
• Daria Brambilla,
• Gloria Berlier,
• Giancarlo Cravotto and
• Katia Martina

Beilstein J. Org. Chem. 2025, 21, 1462–1476, doi:10.3762/bjoc.21.108

• benzoxazole with piperidine. Efficacy of silica-supported Cu(I) and Cu(II) in promoting the C2-amination of benzoxazole with piperidine. Copper-supported catalysts. Supporting Information Supporting Information File 24: Experimental procedures, compound characterization data, and copies of NMR spectra

Wittig reaction of cyclobisbiphenylenecarbonyl

• Taito Moribe,
• Junichiro Hirano,
• Hideaki Takano,
• Hiroshi Shinokubo and
• Norihito Fukui

Beilstein J. Org. Chem. 2025, 21, 1454–1461, doi:10.3762/bjoc.21.107

• depict flattened chemical structures in the reaction schemes. Results and Discussion Synthesis and characterization Methylenetriphenylphosphorane was generated by mixing equimolar amounts of methyltriphenylphosphonium iodide ([MePPh3]I) and sodium tert-butoxide (NaOt-Bu) in THF. The Wittig reaction of

Advances in nitrogen-containing helicenes: synthesis, chiroptical properties, and optoelectronic applications

• Meng Qiu,
• Jing Du,
• Nai-Te Yao,
• Xin-Yue Wang and
• Han-Yuan Gong

Beilstein J. Org. Chem. 2025, 21, 1422–1453, doi:10.3762/bjoc.21.106

• and co-workers reported a series of superhelicenes that combine helical and planar π-systems. However, the structural characterization of compound 1 (Table 1) was impeded by its inherent instability, limiting further analysis [14]. In 2024, Liu’s group developed a series of nonalternant nanographenes

Reactions of acryl thioamides with iminoiodinanes as a one-step synthesis of N-sulfonyl-2,3-dihydro-1,2-thiazoles

• Vladimir G. Ilkin,
• Pavel S. Silaichev,
• Valeriy O. Filimonov,
• Tetyana V. Beryozkina,
• Margarita D. Likhacheva,
• Pavel A. Slepukhin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2025, 21, 1397–1403, doi:10.3762/bjoc.21.104

• Information Supporting Information File 15: Full experimental details and characterization data of all new compounds. Supporting Information File 16: Copies of NMR and HRMS spectra of all new compounds. Funding We gratefully acknowledge financial support of this work by the Russian Science Foundation

N-Salicyl-amino acid derivatives with antiparasitic activity from Pseudomonas sp. UIAU-6B

• Joy E. Rajakulendran,
• Emmanuel Tope Oluwabusola,
• Michela Cerone,
• Terry K. Smith,
• Olusoji O. Adebisi,
• Adefolalu Adedotun,
• Gagan Preet,
• Sylvia Soldatou,
• Hai Deng,
• Rainer Ebel and
• Marcel Jaspars

Beilstein J. Org. Chem. 2025, 21, 1388–1396, doi:10.3762/bjoc.21.103

• isolation of five phenolic siderophores with some of them exhibiting antimicrobial properties, including pseudomonins A–C and pseudomobactins A and B [15]. In this study we report the isolation and structural characterization of two previously undescribed as natural products (1 and 2) and two new compounds

Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes

• Bartłomiej Pigulski

Beilstein J. Org. Chem. 2025, 21, 1272–1305, doi:10.3762/bjoc.21.99

• -workers reported the synthesis of non-benzenoid open-shell nanographene 26 from partially saturated precursor 25 in 25% yield after oxidation using DDQ (Scheme 4) [40]. Extensive characterization of the resulting nanographene in solution revealed a low optical gap, and an open-shell singlet ground state

Synthesis of β-ketophosphonates through aerobic copper(II)-mediated phosphorylation of enol acetates

• Alexander S. Budnikov,
• Igor B. Krylov,
• Fedor K. Monin,
• Valentina M. Merkulova,
• Alexey I. Ilovaisky,
• Liu Yan,
• Bing Yu and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2025, 21, 1192–1200, doi:10.3762/bjoc.21.96

• phosphorylation of enol acetates. Optimization of reaction conditions for the synthesis of β-ketophosphonate 3a from enol acetate 1a and diisopropyl H-phosphonate (2a)a. Supporting Information Supporting Information File 4: Experimental details, compound characterization data, and NMR spectra. Funding This work

Selective monoformylation of naphthalene-fused propellanes for methylene-alternating copolymers

• Kenichi Kato,
• Tatsuki Hiroi,
• Seina Okada,
• Shunsuke Ohtani and
• Tomoki Ogoshi

Beilstein J. Org. Chem. 2025, 21, 1183–1191, doi:10.3762/bjoc.21.95

• conditions (Figure 2a). Insoluble solids, [3.3.3]_branch and [4.3.3]_branch, were obtained due to formation of bonding networks and washed repeatedly with CH2Cl2, H2O, and acetone. Characterization of methylene-alternating copolymers The thermal stability of the oligomers and polymers were evaluated with

A multicomponent reaction-initiated synthesis of imidazopyridine-fused isoquinolinones

• Ashutosh Nath,
• John Mark Awad and
• Wei Zhang

Beilstein J. Org. Chem. 2025, 21, 1161–1169, doi:10.3762/bjoc.21.92

• -aromatization. Optimization of IMDA and re-aromatization reactions for the preparation of 8a. Supporting Information Supporting Information File 50: General reaction procedures, compound characterization data, and copies of NMR spectra. Conflict of Interest The authors declare no competing financial interest.

A versatile route towards 6-arylpipecolic acids

• Erich Gebel,
• Cornelia Göcke,
• Carolin Gruner and
• Norbert Sewald

Beilstein J. Org. Chem. 2025, 21, 1104–1115, doi:10.3762/bjoc.21.88

• and dihedral angles ϕ for both protons H2 and H6 as well as the resulting conformation for the compound. Supporting Information Supporting Information File 38: Experimental procedures, characterization data and NMR spectra. Acknowledgements The authors thank the analytic department at University

Supramolecular assembly of hypervalent iodine macrocycles and alkali metals

• Krishna Pandey,
• Lucas X. Orton,
• Grayson Venus,
• Waseem A. Hussain,
• Toby Woods,
• Lichang Wang and
• Kyle N. Plunkett

Beilstein J. Org. Chem. 2025, 21, 1095–1103, doi:10.3762/bjoc.21.87

• protocol, and the characterization data are consistent with the original dataset [18]. Through a series of crystallographic experiments, we demonstrate that HIMs coordinate with alkali metals through the periphery carbonyl oxygens via metal–oxygen bonding to form a higher order metal-coordinated

Pd-Catalyzed asymmetric allylic amination with isatin using a P,olefin-type chiral ligand with C–N bond axial chirality

• Natsume Akimoto,
• Kaho Takaya,
• Yoshio Kasashima,
• Kohei Watanabe,
• Yasushi Yoshida and
• Takashi Mino

Beilstein J. Org. Chem. 2025, 21, 1018–1023, doi:10.3762/bjoc.21.83

• allylic amination of acetate 12 with isatin (11a).a Supporting Information Data of thermal racemization of 7, DFT calculations for investigating racemization mechanism of 7, general methods and materials, experimental procedures and characterization data, 1H, 13C and 31P NMR spectra for 9 and 10, 1H, 13C

• and 31P NMR spectra and HPLC charts for (±)-7, (+)-7 and (–)-7, 1H and 13C NMR spectra and HPLC charts for (S)-13a–k (except (S)-13e) and (S)-16. Supporting Information File 18: Experimental section and compounds characterization. Funding This work was supported by a Grant-in-Aid for Scientific

On the photoluminescence in triarylmethyl-centered mono-, di-, and multiradicals

• Daniel Straub,
• Markus Gross,
• Mona E. Arnold,
• Julia Zolg and
• Alexander J. C. Kuehne

Beilstein J. Org. Chem. 2025, 21, 964–998, doi:10.3762/bjoc.21.80

Study of tribenzo[b,d,f]azepine as donor in D–A photocatalysts

• Katy Medrano-Uribe,
• Jorge Humbrías-Martín and
• Luca Dell’Amico

Beilstein J. Org. Chem. 2025, 21, 935–944, doi:10.3762/bjoc.21.76

• powerful, efficient and versatile organic photocatalysts. We herein present the design, synthesis and study of a new sulfur-based D–A family using diverse nitrogen donors (Figure 1b). We performed complete photophysical characterization of the diverse D–A molecules to analyze the structure–properties

• promising redox potentials in their excited states, indicating their potential to function as effective bimodal photocatalysts. Additionally, our photophysical characterization provided essential insights into their behavior in the excited state and stability. We initiated the study of the photocatalytic

• ). Giese addition using N-Cbz-Pro (12) and dimethyl maleate (13). Pinacol coupling of benzaldehyde (15). Supporting Information Supporting Information File 10: Reactivity studies, general experimental procedures, product isolation and characterization, spectroscopic data for new compounds, and copies of

A convergent synthetic approach to the tetracyclic core framework of khayanolide-type limonoids

• Zhiyang Zhang,
• Jialei Hu,
• Hanfeng Ding,
• Li Zhang and
• Peirong Rao

Beilstein J. Org. Chem. 2025, 21, 926–934, doi:10.3762/bjoc.21.75

• crystallographic data for this paper. These data can be obtained free of charge via the joint Cambridge Crystallographic Data Centre (CCDC) and Fachinformationszentrum Karlsruhe Access Structures service. Supporting Information File 8: Experimental procedures, NMR spectra and other characterization data for all