Asymmetric synthesis of β-amino cyanoesters with contiguous tetrasubstituted carbon centers by halogen-bonding catalysis with chiral halonium salt

• Yasushi Yoshida,
• Maho Aono,
• Takashi Mino and
• Masami Sakamoto

Beilstein J. Org. Chem. 2025, 21, 547–555, doi:10.3762/bjoc.21.43

• for the construction of contiguous tetrasubstituted carbon centers via the Mannich reaction and this work. Plausible reaction mechanism. Catalyst screening for the asymmetric Mannich reaction. All yields were determined by 1H NMR spectroscopy using 1,3,5-trimethoxybenzene as an internal standard. N

• -Protecting group optimization for the asymmetric Mannich reaction. All yields were determined by 1H NMR spectroscopy using 1,3,5-trimethoxybenzene as an internal standard. aReaction conducted for 24 h. Catalyst screening using 7b as a substrate. All yields were determined by 1H NMR spectroscopy using 1,3,5

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

• photochemical reaction. Its structure was elucidated by NMR spectroscopy and single crystal X-ray diffractometry. The latter revealed no π–π interaction between neighboring ANTH cores. A combination of high photoluminescence quantum yield (PLQY) of 0.85 for 9,10-ANTH(BnF)2, its significantly improved

Synthesis of the aggregation pheromone of Tribolium castaneum

• Biyu An,
• Xueyang Wang,
• Ao Jiao,
• Qinghua Bian and
• Jiangchun Zhong

Beilstein J. Org. Chem. 2025, 21, 510–514, doi:10.3762/bjoc.21.38

• of (R)-2-methyloxirane ((R)-2) with allylmagnesium bromide (3) catalyzed by CuI produced a mixture of (R)-hex-5-en-2-ol ((R)-4) and (S)-2-methylpent-4-en-1-ol ((S)-4’) (ratio 8:1, determined by 1H NMR spectroscopy) [25][26]. The primary alcohol (S)-4’ could be easily removed by a selective TEMPO

• the aggregation pheromone (4R,8S)-1, (4S,8R)-1, and (4S,8S)-1 were prepared through Li2CuCl4-catalyzed coupling and oxidation with RuCl3/NaIO4 from chiral building blocks (R)-10, (S)-10, (R)-11 and (S)-11, which were characterized by NMR spectroscopy and HRMS. Conclusion In summary, we have achieved a

Photomechanochemistry: harnessing mechanical forces to enhance photochemical reactions

• Francesco Mele,
• Ana M. Constantin,
• Andrea Porcheddu,
• Raimondo Maggi,
• Giovanni Maestri,
• Nicola Della Ca’ and
• Luca Capaldo

Beilstein J. Org. Chem. 2025, 21, 458–472, doi:10.3762/bjoc.21.33

• agent 2.2 in a sub-stoichiometric fashion (20 mol %). However, even upon prolonged exposure, the yield of 2.3 did not exceed 20% (by 1H NMR spectroscopy). To achieve turnover, the photoreacted solid was subjected to a second grinding and exposed again to UV irradiation for an additional 16 h, which

• resulted in 40% yield. Alternating grinding and irradiation, the authors managed to obtain quantitative conversion of 2.1 to 2.3. Overall, in this work, mechanochemistry worked akin to agitation provided by stirring or heating in solution. In fact, 1H NMR spectroscopy, XRD and DFT analyses showed that

• when a 1:1 mixture of p-di[2-(4-pyridyl)ethenyl]benzene (5.1) and 4-benzylresorcinol (5.2) was ground with a mortar and pestle (1 h) and then irradiated with a low-pressure Hg lamp (60 h), [2.2]paracyclophane (5.3) was formed in poor yield (35% by 1H NMR spectroscopy). Dry vortex grinding did not

Electrochemical synthesis of cyclic biaryl λ³-bromanes from 2,2’-dibromobiphenyls

• Andrejs Savkins and
• Igors Sokolovs

Beilstein J. Org. Chem. 2025, 21, 451–457, doi:10.3762/bjoc.21.32

• improving the substrate scope and understanding the reaction mechanism are in progress in our laboratory. Synthesis of cyclic diarylbromonium compounds. Substrate scope. Reactions were performed on a 0.15 mmol scale. Yields were determined by 1H NMR spectroscopy of the reaction mixture using 1,2,3,4

New tandem Ugi/intramolecular Diels–Alder reaction based on vinylfuran and 1,3-butadienylfuran derivatives

• Yuriy I. Horak,
• Roman Z. Lytvyn,
• Andrii R. Vakhula,
• Yuriy V. Homza,
• Nazariy T. Pokhodylo and
• Mykola D. Obushak

Beilstein J. Org. Chem. 2025, 21, 444–450, doi:10.3762/bjoc.21.31

• products were identified via NMR as 4,4a,5,6,7,7a-hexahydro-3aH-furo[2,3-f]isoindoles. The structures of compounds 5 were confirmed by NMR spectroscopy data (for details and discussion see Supporting Information File 1). The NMR data for the obtained furoindole skeleton signals and spin-coupling constants

• these compounds were confirmed by NMR spectroscopy (see Supporting Information File 1). Conclusion In summary, we showed the practical usage of 3-(furan-2-yl)acrylaldehyde in the four-component Ugi reaction with the prospect of further intramolecular [4 + 2] cycloaddition of the Ugi reaction product. We

The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation

• Rituparna Das and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27

• investigated the role of the C-2 protecting group in Schmidt’s trichloroacetimidate glycosylation with donor 60 which showed excellent yield along with the formation of the 1,2-trans glycoside only. They proposed the mechanism with the help of NMR spectroscopy and the studies revealed that the N

• species was confirmed by low temperature NMR spectroscopy. Similarly, Ito et al. also introduced the concept of using 2-O-(o-tosylamido)benzyl (TAB)-modified donor 103 for the stereocontrolled synthesis of both 1,2-cis and 1,2-trans glycosides under modified reaction conditions [154][155]. They

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

• 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

• proton is shifted to a stronger field of 14.23 ppm and appears as a narrow singlet (Supporting Information File 2, Figure S17). Analysis of two-dimensional correlation spectra of heteronuclear NMR spectroscopy shows that compound 7a in DMSO-d6 solution exists in the (NH) tautomeric form. Thus, in the 1H

• -ray diffraction analysis. Using two-dimensional correlation NMR spectroscopy methods, it was shown that the nature of the solvent significantly affects the equilibrium of the tautomeric forms of the 1,3-tropolones. The obtained compounds represent molecular switches of optical and fluorescent

Synthesis, characterization, antimicrobial, cytotoxic and carbonic anhydrase inhibition activities of multifunctional pyrazolo-1,2-benzothiazine acetamides

• Ayesha Saeed,
• Shahana Ehsan,
• Muhammad Zia-ur-Rehman,
• Erin M. Marshall,
• Sandra Loesgen,
• Abdus Saleem,
• Simone Giovannuzzi and
• Claudiu T. Supuran

Beilstein J. Org. Chem. 2025, 21, 348–357, doi:10.3762/bjoc.21.25

• and 13C NMR spectroscopy. All compounds were tested against five human microbial strains including three different strains of Staphylococcus aureus (ATCC 25923, ATCC BAA-41, and ATCC BAA-44), Escherichia coli (ATCC 8739), and Candida albicans (ATCC 90027) to evaluate their antibiotic potential. The

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

• -dihydronaphtho[1,2-b]furan-3-carboxylate 4a,b with a total yield of up to 73% (ratio 3a/4a = 2:1; 3b/4b = 2:1, according to 1H NMR spectroscopy) (Scheme 4). Using preparative chromatography, the mixture was separated into individual substances. In turn, alkyl 7,7-dimethyl-4,9-dioxo-6,7,8,9-tetrahydro-4H-furo[3,2

Antibiofilm and cytotoxic metabolites from the entomopathogenic fungus Samsoniella aurantia

• Rita Toshe,
• Syeda J. Khalid,
• Blondelle Matio Kemkuignou,
• Esteban Charria-Girón,
• Paul Eckhardt,
• Birthe Sandargo,
• Kunlapat Nuchthien,
• J. Jennifer Luangsa-ard,
• Till Opatz,
• Hedda Schrey,
• Sherif S. Ebada and
• Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 327–339, doi:10.3762/bjoc.21.23

• . Supporting Information Supporting Information File 6: HRESIMS profiles and NMR spectroscopic data of compounds 1–6. Acknowledgements The authors thank S. Reinecke, C. Kakoschke, E. Surges and W. Collisi for their generous technical assistance, acquiring HRESIMS, NMR spectroscopy, antimicrobial and

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

• 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

Three-component reactions of conjugated dienes, CH acids and formaldehyde under diffusion mixing conditions

• Dmitry E. Shybanov,
• Maxim E. Kukushkin,
• Eugene V. Babaev,
• Nikolai V. Zyk and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2025, 21, 262–269, doi:10.3762/bjoc.21.18

• an important role; the presence of the condensation catalyst ʟ-proline accelerated the absorption of formaldehyde vapors by the reaction mixture. Carrying out the same reaction in the absence of a catalyst in CDCl3 and subsequent 1H NMR spectroscopy analysis showed that the mixture contained 42% of

• cyanoacetic ester and acetylacetone. The configuration of the products 4 and 5 was established by bromination of a small amount of these isomeric compounds in CDCl3 (Scheme 6) and subsequent analysis of the mixture by 1H NMR spectroscopy. For the stereoisomers 4, the main product was lactone 22, identified by

• [27]. The three-component reaction with acetoacetic ester was highly selective, and the formation of a minor [4 + 2]-cycloaddition product was not observed (according to 1H NMR spectroscopy), but the yield of the products 15 did not exceed 9%. For acetylacetone, the reaction was the least selective

Effect of substitution position of aryl groups on the thermal back reactivity of aza-diarylethene photoswitches and prediction by density functional theory

• Misato Suganuma,
• Daichi Kitagawa,
• Shota Hamatani and
• Seiya Kobatake

Beilstein J. Org. Chem. 2025, 21, 242–252, doi:10.3762/bjoc.21.16

• previous work [56][57], whereas compounds N4 and I1–I4 were synthesized according to Scheme 2 in the Experimental section. The chemical structures of all compounds were confirmed by 1H NMR and 13C NMR spectroscopy and high-resolution mass spectrometry. 1H NMR and 13C NMR spectra are shown in Supporting

Streamlined modular synthesis of saframycin substructure via copper-catalyzed three-component assembly and gold-promoted 6-endo cyclization

• Asahi Kanno,
• Ryo Tanifuji,
• Satoshi Yoshida,
• Sota Sato,
• Saori Maki-Yonekura,
• Kiyofumi Takaba,
• Jungmin Kang,
• Kensuke Tono,
• Koji Yonekura and
• Hiroki Oguri

Beilstein J. Org. Chem. 2025, 21, 226–233, doi:10.3762/bjoc.21.14

• a fluorescent intermediate 18, and subsequent ring opening allowed a streamlined one-pot access to the substructure of THIQ alkaloids 14 in a good yield of 60% from 11. The structure of the resulting 14 was elucidated through comprehensive two-dimensional NMR spectroscopy, complemented by NOE

Quantifying the ability of the CF₂H group as a hydrogen bond donor

• Matthew E. Paolella,
• Daniel S. Honeycutt,
• Bradley M. Lipka,
• Jacob M. Goldberg and
• Fang Wang

Beilstein J. Org. Chem. 2025, 21, 189–199, doi:10.3762/bjoc.21.11

• donation ability of the CF2H group by 1H NMR titration with tri-n-butylphosphine oxide (n-Bu3PO) as a reference HB acceptor (Figure 4A and Figures S20–S40 in Supporting Information File 1). Unlike a previous method that relied on 31P NMR spectroscopy [52], our titration monitors the HB complex formation by

Hydrogen-bonded macrocycle-mediated dimerization for orthogonal supramolecular polymerization

• Wentao Yu,
• Zhiyao Yang,
• Chengkan Yu,
• Xiaowei Li and
• Lihua Yuan

Beilstein J. Org. Chem. 2025, 21, 179–188, doi:10.3762/bjoc.21.10

• molar ratio observed in ESI experiments. These inspiring results prompted us to further examine the interaction between host H1 and G1 by 1H NMR spectroscopy. Our prior experience with cyclo[6]aramide has confirmed binding to the cationic guest [49]. Indeed, addition of compound H1 to the guest solution

• mixture of G2 and zinc salt in CHCl3/CH3CN (1:1, v/v) was subjected to 1H NMR spectroscopy. Protons H2–H4, H7, H8, H11, and H12 of G2, located around the metal coordination site, were found to experience upfield or downfield shifts to a varying extent (Figure S8, Supporting Information File 3

• , which is characteristic for the formation of supramolecular polymers. The concentration-dependency of a mixture of H1, G2, and zinc salt was examined by variable-concentration NMR spectroscopy. Pronounced broadening of signals was observed (Figure 8), which clearly indicated increasing polymerization

Nickel-catalyzed cross-coupling of 2-fluorobenzofurans with arylboronic acids via aromatic C–F bond activation

• Takeshi Fujita,
• Haruna Yabuki,
• Ryutaro Morioka,
• Kohei Fuchibe and
• Junji Ichikawa

Beilstein J. Org. Chem. 2025, 21, 146–154, doi:10.3762/bjoc.21.8

• , excluding boronic acid 2a (Scheme 6). The reaction was monitored using 19F and 31P NMR spectroscopy. The 19F NMR analysis showed that 79% of 1b remained and revealed a new broad double doublet peak at 55.0 ppm (JFP = 53, 42 Hz) relative to internal C6F6 (δ = 0.0 ppm). The 31P NMR spectrum depicted broad

Emerging trends in the optimization of organic synthesis through high-throughput tools and machine learning

• Pablo Quijano Velasco,
• Kedar Hippalgaonkar and
• Balamurugan Ramalingam

Beilstein J. Org. Chem. 2025, 21, 10–38, doi:10.3762/bjoc.21.3

• four-step process involves allylation, Claisen rearrangement, isomerization, and oxidative dimerization. Each reaction step was optimized independently by using either online HPLC or in-line benchtop NMR spectroscopy to afford an overall yield of 67% in 66 iterative experiments over four linear

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

• available 2-bromo-4-fluoro-1-nitrobenzene, featuring a noble-metal-free system, mild reaction conditions, and a good yield, especially for the final Cs2CO3-facilitated nucleophilic substitution (77–91% yield). The characterization data obtained from IR and NMR spectroscopy (1H, 13C, 19F, and 31P) as well as

• 2–7 was performed by NMR spectroscopy, which confirmed the synthetic outcomes (Figures S1–S11, Supporting Information File 1). The structures of compounds 7 were further confirmed by HRMS and IR analyses (Figures S12–S18, Supporting Information File 1). In addition, the chemical structure of 7-H was

Hypervalent iodine-mediated intramolecular alkene halocyclisation

• Charu Bansal,
• Oliver Ruggles,
• Albert C. Rowett and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258

• . The level of this chemoselectivity was dependent on the iodane ligand: OPiv was more selective for aminofluorination than OAc, which was proposed to be due to differences in basicity and nucleophilicity (Scheme 10). Detailed mechanistic studies were carried out using multinuclear NMR spectroscopy

Synthesis of the 1,5-disubstituted tetrazole-methanesulfonylindole hybrid system via high-order multicomponent reaction

• Cesia M. Aguilar-Morales,
• América A. Frías-López,
• Nadia V. Emilio-Velázquez,
• Alejandro Islas-Jácome,
• Angelica Judith Granados-López,
• Jorge Gustavo Araujo-Huitrado,
• Yamilé López-Hernández,
• Hiram Hernández-López,
• Luis Chacón-García,
• Jesús Adrián López and
• Carlos J. Cortés-García

Beilstein J. Org. Chem. 2024, 20, 3077–3084, doi:10.3762/bjoc.20.256

• and resource optimization. In addition, all the target compounds were fully characterized using 1H and 13C NMR spectroscopy and HRMS. It is important to mention that this protocol cannot be considered a true one-pot synthesis, as it requires a solvent exchange between reaction steps (e.g., from

Enantioselective regiospecific addition of propargyltrichlorosilane to aldehydes catalyzed by biisoquinoline N,N’-dioxide

• Noble Brako,
• Sreerag Moorkkannur Narayanan,
• Amber Burns,
• Layla Auter,
• Valentino Cesiliano,
• Rajeev Prabhakar and
• Norito Takenaka

Beilstein J. Org. Chem. 2024, 20, 3069–3076, doi:10.3762/bjoc.20.255

• reaction mixture, but a trace amount of it was detected after the distillation (propargyltrichlorosilane/allenyltrichlorosilane = 200:1 by 1H NMR spectroscopy, see Supporting Information File 1 for details). With distilled propargyltrichlorosilane (>99% isomeric purity) in hand, we set out on our study on

• propargyltrichlorosilane. Evaluation of C2-symmetric catalysts with benzaldehyde (1a) as a model aldehyde. Reaction conditions: 1a (0.1 mmol), silane (0.15 mmol), catalyst (0.01 mmol), CH2Cl2 (0.4 mL); yields were determined by 1H NMR spectroscopy with 1,1,2,2-tetrachloroethane as an internal standard following workup and

• stationary phase, yields were determined by 1H NMR spectroscopy with 1,1,2,2-tetrachloroethane as an internal standard following workup and isolated yields are given in parentheses. aReaction conditions: 1a (1.0 mmol), silane (1.5 mmol), (S)-8 (0.1 mmol), CH2Cl2 (4.0 mL). Supporting Information Supporting

Extension of the π-system of monoaryl-substituted norbornadienes with acetylene bridges: influence on the photochemical conversion and storage of light energy

• Robin Schulte,
• Dustin Schade,
• Thomas Paululat,
• Till J. B. Zähringer,
• Christoph Kerzig and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 3061–3068, doi:10.3762/bjoc.20.254

• because by-products interfered with the chromatographic separation; however, these yields are similar to the ones reported for resembling norbornadienes [34][37]. The novel compounds 1h–l,n were identified and fully characterized by NMR spectroscopy (1H, 13C, COSY, HSQC, HMBC), melting point, and

• by 1H NMR spectroscopy. Initially, all derivatives showed the isomerization reactions to the corresponding quadricyclane derivatives, as identified by the characteristic 1H NMR signal pattern of the quadricyclane fragment with five multiplets at around 1.6 ppm, 1.7 ppm, 1.8 ppm, 2.1 ppm, and 2.2 ppm

• quadricyclane signals, so that the quantitative analysis of the photostationary state was not possible with NMR spectroscopy. These observations are surprising, since the 3-acceptor-substituted derivatives and the ones without acetylene linkers have been reported to be converted quantitatively into their

gem-Difluorovinyl and trifluorovinyl Michael acceptors in the synthesis of α,β-unsaturated fluorinated and nonfluorinated amides

• Monika Bilska-Markowska,
• Marcin Kaźmierczak,
• Wojciech Jankowski and
• Marcin Hoffmann

Beilstein J. Org. Chem. 2024, 20, 2946–2953, doi:10.3762/bjoc.20.247

• E-isomer of products 9 were identified. The fluorine atom signals of 9a–d were located at approximately −112 ppm (triplets, J ≈ 27 Hz, Fβ) and at −155 to −159 ppm (multiplets, Fα). The stereochemistry was determined by 19F{1H} NMR spectroscopy. The observed coupling constants J ≈ 2 Hz between

• addition–elimination reaction, affording the corresponding fluorinated 13a–d (Scheme 4) and nonfluorinated 14a–d (Scheme 5) unsaturated products. Also this time, for compounds 13a–d, the formation of only Z isomers was observed (Scheme 4). The stereochemistry was determined by 19F{1H} NMR spectroscopy