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

• unambiguously confirmed by X-ray diffraction. Keywords: allomaltol; enamines; 2H-furo[3,2-b]pyran-2-ones; pyrazol-3-ones; recyclization; Introduction Substituted furan-2(5H)-ones (butenolides) are widely used as precursors for the preparation of diverse types of heterocyclic compounds possessing various

• units was isolated (Scheme 9). The structure of synthesized compound 13 was unambiguously confirmed by X-ray diffraction. Conclusion In summary, we studied the interaction of 2H-furo[3,2-b]pyran-2-one derivatives with various amines and hydrazines. It was demonstrated that, depending on the nature of

• structures of key synthesized products were unambiguously proved by X-ray diffraction. Various examples of transformations of furanones. Interaction of starting 2H-furo[3,2-b]pyran-2-ones with diverse amines. Synthesis of enamines 4. Reaction conditions: 1a (1 mmol, 0.38 g), amine 2 (1.2 mmol), AcOH (3 mL

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

• control of equivalents and pH, or Leuckart–Wallach-like reaction with ammonium formate and Pd/C [25] provided monomethylaniline 7 in 37% and 35% yield, respectively. The absolute structure of monomethylaniline 7 was confirmed by single-crystal X-ray diffraction measurements (Figure 2). Compound 7

• conjugation handles in unit B. IC50 values given against (a) CCRF-CEM [20] and (b) KB-3-1 [21] cell lines. C: Cryptophycin-52 derivatives synthesised in this work. Molecular structure of Boc-ᴅ-Phe(4-NHMe)-OMe 7 as determined by single-crystal X-ray diffraction measurements. Thermal ellipsoids depicted at 50

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

• ratio was found to be 1.74 (theoretical = 1.75), confirming the composition to be ANTH(BnF)2. Slow evaporation of a CH2Cl2 solution of 9,10-ANTH(BnF)2 at 2 °C afforded off-white plates suitable for X-ray diffraction. The structure shown in Figure 2 (top panel) confirmed the 9,10-substitution pattern

• -10-bis(perfluorobenzyl)anthracene were mounted in a paratone oil on glass fiber rods glued to a small copper wire. X-ray diffraction data were collected at ChemMatCARS (CARS = consortium for advanced radiation sources) sector 15-B at the Advanced Photon Source (Argonne National Laboratory). The data

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

• Figure 2b. We hypothesized that this reaction occurred in the solid state, and further investigations confirmed this. To validate our findings, we employed single-crystal X-ray diffraction, which revealed the packing mode in the crystal and identified any photoproducts formed. Two additional compounds

• included two additional bimane samples, Me2B and Me4B. These samples were crystallized from a MeOH–DCM 1:1 (v/v) mixture which was left to slowly evaporate over the course of several days at room temperature, followed by single-crystal X-ray diffraction to determine their structure (Figure 4) and crystal

• fluorescence spectrum and η is the refractive index of the solvent. Single crystal X-ray diffraction studies Crystals of Me4B, Cl2B (A), (B), (C), and Me2B were mounted on a MiTeGen micromount with NVH immersion oil. Data were collected from a shock-cooled single crystal at 100(2) K on a Bruker Apex Kappa Duo

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

• determined. The structure of 2-(3,3-dimethyl-3H-benzo[g]indolin-2-yl)-5,6,7-trichloro-1,3-tropolone was determined by X-ray diffraction analysis. The compounds obtained are capable of switching emission at 420–440 nm and 476–530 nm upon successive exposure to CN− and Hg2+ ions in an acetonitrile solution. 2

• -(1,1-Dimethyl-1H-benzo[e]indolin-2-yl)-5,6,7-trichloro-1,3-tropolone exhibited high in vitro cytotoxic activity against A431 skin cancer and H1299 lung cancer cell lines. Keywords: cytotoxic activity; fluorescence; o-chloranil; quantum chemical DFT calculations; 1,3-tropolones; X-ray diffraction

• reaction of o-chloranil with benzoannelated derivatives of 2,3,3-trimethylindolenine, a comprehensive evaluation of the structure of the compounds obtained using quantum chemical methods, X-ray diffraction analysis, two-dimensional correlation NMR spectroscopy, as well as investigation of their ionochromic

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

• of the synthesized compounds were proven by a set of physicochemical methods, including X-ray diffraction analysis. Keywords: CH-acids; 1-halo-1-nitroethenes; heterocyclization; nitroacrylates; X-ray diffraction analysis; Introduction The combination of the furan ring with various carbo- and

• case of 2e) or alcohol (in the case of 2f,g) solution for 1–3 h (ratio of acrylate/CH-acid/AcOK = 1:1:1.5) with a yield of 43–64% (Scheme 7). The structures of the obtained condensed furans 3–7 were characterized by a set of physicochemical methods, including X-ray diffraction analysis. Analysis of the

• frequency values (1725–1731 cm−1). This observation may be due to the position of the ester fragment relative to the heterocyclic system. The analysis of the results of X-ray diffraction analysis shows that the torsion angle C(10)–C(3)–C(16)–O(17) of methyl esters 5a and 6c is −0.8(2), and 5(2)°, and of

Molecular diversity of the reactions of MBH carbonates of isatins and various nucleophiles

• Zi-Ying Xiao,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2025, 21, 286–295, doi:10.3762/bjoc.21.21

• yields. The single crystal structure of the compound 6e was determined by X-ray diffraction (Figure 3). The similar reaction of more nucleophilic tri(tert-butyl)phosphine and MBH carbonate of isatin resulted in a mixture of products. After carefully screening the reaction conditions, we found that DABCO

• triene derivatives can be prepared under relative mild reaction conditions with good steric selectivity. The single crystal structures of compounds 7a and 8a were successfully determined by X-ray diffraction method (Figure 4 and Figure 5). From the crystal structures, it can be found that the compound 7a

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

• -0495, Japan X-ray diffraction facility, Department of Chemistry, 100 E. 24th Street, The University of Texas at Austin, Austin, TX 78712, USA 10.3762/bjoc.21.19 Abstract A benzo[rst]pentaphene (BPP) substituted by an isopropoxy group (BPP-OiPr) was synthesized in a facile manner. Its photophysical

• ferric chloride (FeCl3) gave BPP-dione 4 in 70% yield. The chemical structures of BPP-OiPr 3 and BPP-dione 4 were characterized by 1H and 13C NMR spectroscopy as well as mass spectrometry (see Supporting Information File 1, Figures S8–S11). A single crystal of BPP-OiPr 3 suitable for X-ray diffraction

• analysis was obtained by slow evaporation of a diethyl ether/n-hexane solution, enabling its unambiguous structural determination by single-crystal X-ray diffraction (Figure 1). The planar BPP core and the isopropyloxy group on the zigzag edge are clearly visualized (Figure 1a and b). In a unit cell

Synthesis, characterization, and photophysical properties of novel 9‑phenyl-9-phosphafluorene oxide derivatives

• Shuxian Qiu,
• Duan Dong,
• Jiahui Li,
• Huiting Wen,
• Jinpeng Li,
• Yu Yang,
• Shengxian Zhai and
• Xingyuan Gao

Beilstein J. Org. Chem. 2024, 20, 3299–3305, doi:10.3762/bjoc.20.274

• HRMS spectrometry were in full agreement with the expected structures, and single-crystal X-ray diffraction analysis was conducted to confirm the structure of compound 7-H. Moreover, the photophysical properties of these PhFlOP derivatives were determined by UV–vis absorption and photoluminescence

• simple. The structure of 7-H was confirmed by single-crystal X-ray diffraction. Furthermore, UV–vis absorption and PL studies were carried out to explore the photophysical properties of these PhFlOP derivatives. Investigations for further applications of the PhFlOP-based emitters 7 are still ongoing. An

Reactivity of hypervalent iodine(III) reagents bearing a benzylamine with sulfenate salts

• Beatriz Dedeiras,
• Catarina S. Caldeira,
• José C. Cunha,
• Clara S. B. Gomes and
• M. Manuel B. Marques

Beilstein J. Org. Chem. 2024, 20, 3281–3289, doi:10.3762/bjoc.20.272

• benziodoxolone, 2d) were obtained with quantitative yields, as white solids on the gram-scale, easy to manipulate and long-term stable below 0 °C. Crystals of compound 2d were successfully obtained and its molecular structure was confirmed through single-crystal X-ray diffraction. The X-ray analysis revealed a

• the electrophilic amination of tert-butyl 3-(p-tolylsulfinyl)propanoate (4a) with BBX 2a (0.23 mmol of limitant in 2 mL of solvent). Supporting Information Supporting Information File 54: Experimental procedures, characterization data, NMR spectra, and X-ray diffraction data. Funding The authors

Synthesis of 2H-azirine-2,2-dicarboxylic acids and their derivatives

• Anastasiya V. Agafonova,
• Mikhail S. Novikov and
• Alexander F. Khlebnikov

Beilstein J. Org. Chem. 2024, 20, 3191–3197, doi:10.3762/bjoc.20.264

• single-crystal X-ray diffraction analysis. The reaction of azetidine with diacyl chloride 2a gave a complex mixture of products, and O-methyl hydroxylamine did not react. Diacyl chloride 2a reacts with methanol and ethanol to give diesters 11a,b (Scheme 5). An experiment with isoxazole 1a and methanol on

• research was carried out using resources of the Centre for Magnetic Resonance, the Research Centre for X-ray Diffraction Studies, the Centre for Chemical Analysis and Materials, and the Computer Centre of the Science Park of St. Petersburg State University. Funding This work was supported by Russian

Synthesis of extended fluorinated tripeptides based on the tetrahydropyridazine scaffold

• Thierry Milcent,
• Pascal Retailleau,
• Benoit Crousse and
• Sandrine Ongeri

Beilstein J. Org. Chem. 2024, 20, 3174–3181, doi:10.3762/bjoc.20.262

• trifluoro/difluoromethylated tetrahydropyridazine acids. Synthetic strategy to obtain fluorinated tetrahydropyridazines from difluoro- or trifluoromethylated hydrazones. X-ray diffraction of compound 8f. Reported syntheses of tetrahydropyridazine ester derivatives. Synthesis of fluorinated hydrazones 3a–f

Controlled oligomerization of [1.1.1]propellane through radical polarity matching: selective synthesis of SF₅- and CF₃SF₄-containing [2]staffanes

• Jón Atiba Buldt,
• Wang-Yeuk Kong,
• Yannick Kraemer,
• Masiel M. Belsuzarri,
• Ansh Hiten Patel,
• James C. Fettinger,
• Dean J. Tantillo and
• Cody Ross Pitts

Beilstein J. Org. Chem. 2024, 20, 3134–3143, doi:10.3762/bjoc.20.259

• truncated after incorporation of two bicyclopentane (BCP) units. Synthetic and computational studies suggest this phenomenon can be attributed to alternating radical polarity matching. In addition, single-crystal X-ray diffraction (SC-XRD) data reveal structurally interesting features of the CF3SF4

• for the first time created an opportunity for structural analysis. We previously reported and contextualized single-crystal X-ray diffraction (SC-XRD) data on 2 [36]; thus, we proceeded to grow crystals of 3 suitable for X-ray analysis through slow evaporation of ethyl acetate. To our surprise, an

4,6-Diaryl-5,5-difluoro-1,3-dioxanes as chiral dopants for liquid crystal compositions

• Maurice Médebielle,
• Peer Kirsch,
• Jérémy Merad,
• Carolina von Essen,
• Clemens Kühn and
• Andreas Ruhl

Beilstein J. Org. Chem. 2024, 20, 2940–2945, doi:10.3762/bjoc.20.246

• enantiomers (R,R)-3/(S,S)-3, (R,R)-4/(S,S)-4 were obtained by slow evaporation from n-heptane solution and structures were determined by X-ray diffraction, which allowed the correlation of the chiroptical properties with the configuration (Figure 2 and Figure 3). The HTP of all enantiomers were measured with

Structure and thermal stability of phosphorus-iodonium ylids

• Andrew Greener,
• Stephen P. Argent,
• Coby J. Clarke and
• Miriam L. O’Duill

Beilstein J. Org. Chem. 2024, 20, 2931–2939, doi:10.3762/bjoc.20.245

• functionalities they can transfer. In this study, a fundamental understanding of the thermal stability of phosphorus-iodonium ylids is obtained through X-ray diffraction, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Insights into the structural factors affecting thermal stability

• ][26][27] and the mechanisms by which they decompose when heated through a systematic investigation of structural data from X-ray diffraction (XRD) and thermal stability data from differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The insights from this study will galvanise

• the rational design and synthesis of novel, unstabilised hypervalent iodine(III) compounds and expand the application of these powerful reagents in organic synthesis. Results and Discussion Structural data Twelve phosphorus-iodonium ylids were synthesised (Figure 2). X-ray diffraction data (XRD) of

The charge transport properties of dicyanomethylene-functionalised violanthrone derivatives

• Sondos A. J. Almahmoud,
• Joseph Cameron,
• Dylan Wilkinson,
• Michele Cariello,
• Claire Wilson,
• Alan A. Wiles,
• Peter J. Skabara and
• Graeme Cooke

Beilstein J. Org. Chem. 2024, 20, 2921–2930, doi:10.3762/bjoc.20.244

• otherwise. The absence of transition states was confirmed by the absence of imaginary frequencies in vibrational frequency calculations. The long side chains were replaced by methyl units to aid the convergence of the geometry optimisations. Crystallography Single crystal X-ray diffraction data for 3b were

Synthesis of pyrrole-fused dibenzoxazepine/dibenzothiazepine/triazolobenzodiazepine derivatives via isocyanide-based multicomponent reactions

• Marzieh Norouzi,
• Mohammad Taghi Nazeri,
• Ahmad Shaabani and
• Behrouz Notash

Beilstein J. Org. Chem. 2024, 20, 2870–2882, doi:10.3762/bjoc.20.241

• studied by X-ray diffraction analysis, and the crystal structure is illustrated in Figure 2 (detailed information can be found in the Supporting Information File 1). The 1H NMR spectrum of product 6f obtained through the I-MCR was investigated and some unexpected chemical shifts were observed at room

Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels

• Connor R. M. MacDonald and
• Emily R. Draper

Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220

Base-promoted cascade recyclization of allomaltol derivatives containing an amide fragment into substituted 3-(1-hydroxyethylidene)tetronic acids

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

Beilstein J. Org. Chem. 2024, 20, 2585–2591, doi:10.3762/bjoc.20.217

• fragment in the region δ = 2.5–2.4 ppm and methylene unit at δ = 2.7–2.5 ppm. The remaining signals are also in good agreement with the presented structure. Besides that, compound 4 has been analyzed using X-ray diffraction (Figure 1). It is important to emphasize that based on X-ray data the structure of

Anion-dependent ion-pairing assemblies of triazatriangulenium cation that interferes with stacking structures

• Yohei Haketa,
• Takuma Matsuda and
• Hiromitsu Maeda

Beilstein J. Org. Chem. 2024, 20, 2567–2576, doi:10.3762/bjoc.20.215

• (100), 595.3 (40), 596.3 (10), [M − BF4]+ calcd for C43H36N3, 594.29; (negative) 86.0 (20), 87.0 (100); [M – C43H36N3]− calcd for BF4, 87.00. This compound was further characterized by single-crystal X-ray diffraction analysis. 4,8,12-Tris(2,6-dimethylphenyl)-4,8,12-triazatriangulenium as a PF6− ion

• (0.21); MALDI–TOF MS (m/z) (% intensity): (positive) 594.3 (100), 595.3 (40), 596.3 (10), [M − F6P]+ calcd for C43H36N3, 594.29; (negative) 145.1 (100), [M − C49H30N3]− calcd for F6P, 144.96. This compound was further characterized by single-crystal X-ray diffraction analysis. 4,8,12-Tris(2,6

• –TOF MS (m/z) (% intensity): (positive) 594.3 (100), 595.3 (40), 596.3 (10), [M − C24BF20]+ calcd for C43H36N3, 594.29; (negative) 678.0 (20), 679.0 (100), 680.0 (20), [M – C43H36N3]– calcd for C24BF20, 678.98. This compound was further characterized by single-crystal X-ray diffraction analysis. 4,8,12

HFIP as a versatile solvent in resorcin[n]arene synthesis

• Hormoz Khosravi,
• Valeria Stevens and
• Raúl Hernández Sánchez

Beilstein J. Org. Chem. 2024, 20, 2469–2475, doi:10.3762/bjoc.20.211

• compounds. Acknowledgements This research was supported through instrumentation made available through the Shared Instrumentation Authority at Rice University. We thank Dr. Christopher L. Pennington for assistance with HRMS data collection and Dr. Hong-Lei Xu for help with single-crystal X-ray diffraction

Synthesis, electrochemical properties, and antioxidant activity of sterically hindered catechols with 1,3,4-oxadiazole, 1,2,4-triazole, thiazole or pyridine fragments

• Daria A. Burmistrova,
• Andrey Galustyan,
• Nadezhda P. Pomortseva,
• Kristina D. Pashaeva,
• Maxim V. Arsenyev,
• Oleg P. Demidov,
• Mikhail A. Kiskin,
• Andrey I. Poddel’sky,
• Nadezhda T. Berberova and
• Ivan V. Smolyaninov

Beilstein J. Org. Chem. 2024, 20, 2378–2391, doi:10.3762/bjoc.20.202

• catechols with a 2-pyridine or 1,3,4-oxadiazole-2-thione ring in the crystalline state were studied by X-ray diffraction. It has been established that the number of heteroatoms in the cycle which are bonded to the catechol ring through a sulfur atom and/or methylene bridge as well as the presence of

Tandem diazotization/cyclization approach for the synthesis of a fused 1,2,3-triazinone-furazan/furoxan heterocyclic system

• Yuri A. Sidunets,
• Valeriya G. Melekhina and
• Leonid L. Fershtat

Beilstein J. Org. Chem. 2024, 20, 2342–2348, doi:10.3762/bjoc.20.200

• additionally confirmed by X-ray diffraction (see Supporting Information File 1 for details) (Figure 2). To confirm the reaction mechanism, we performed diazotization followed by azo coupling of amide 2a using labeled Na15NO2 as the nitrosating reagent (Scheme 4). As a result, 15N-labeled triazinone 8 was

Understanding X-ray-induced isomerisation in photoswitchable surfactant assemblies

• Beatrice E. Jones,
• Camille Blayo,
• Jake L. Greenfield,
• Matthew J. Fuchter,
• Nathan Cowieson and
• Rachel C. Evans

Beilstein J. Org. Chem. 2024, 20, 2005–2015, doi:10.3762/bjoc.20.176

• , depending on the X-ray energy available from laboratory or synchrotron sources. Moreover, this effect may have significant consequences when measuring any light-responsive materials using X-rays, from self-assembled PS systems (using SAXS) to crystalline or powder samples (using X-ray diffraction) [28][29

Regioselective alkylation of a versatile indazole: Electrophile scope and mechanistic insights from density functional theory calculations

• Pengcheng Lu,
• Luis Juarez,
• Paul A. Wiget,
• Weihe Zhang,
• Krishnan Raman and
• Pravin L. Kotian

Beilstein J. Org. Chem. 2024, 20, 1940–1954, doi:10.3762/bjoc.20.170

• Texas A&M University for X-ray diffraction analysis. Funding All studies were funded by BioCryst Pharmaceuticals Inc. Conflict of Interest The authors declare the following competing financial interest(s): All authors are employees/former employees of BioCryst Pharmaceuticals Inc. and may hold stock in