Studies on the syntheses of β-carboline alkaloids brevicarine and brevicolline

• Benedek Batizi,
• Patrik Pollák,
• András Dancsó,
• Péter Keglevich,
• Gyula Simig,
• Balázs Volk and
• Mátyás Milen

Beilstein J. Org. Chem. 2025, 21, 955–963, doi:10.3762/bjoc.21.79

• publications [19][23][24] confirmed the structure with IR and MS data, or by reactivity. Herein, we report the full set of assigned 1H and 13C NMR data for both the base and the dihydrochloride salt. In the course of our efforts devoted to elaborating a new and efficient synthesis of brevicarine (2), we

• . Assigned 1H and 13C NMR data of brevicarine (2) base and its dihydrochloride salt. Supporting Information CCDC 2410549 (31) contain supplementary crystallographic data for this paper. These data are provided free of charge by The Cambridge Crystallographic Data Centre via http://www.ccdc.ac.uk/data

• request/cif. Supporting Information File 6: ORTEP diagram of compound 31, synthetic procedures, IR, 1H, 13C, 19F and 2D NMR spectra of compounds 2, 5, 6, 24–28 and 30–32. Supporting Information File 7: Crystallographic information file of compound 31. Supporting Information File 8: Checkcif file for

Dicarboxylate recognition based on ultracycle hosts through cooperative hydrogen bonding and anion–π interactions

• Wen-Hui Mi,
• Teng-Yu Huang,
• Xu-Dong Wang,
• Yu-Fei Ao,
• Qi-Qiang Wang and
• De-Xian Wang

Beilstein J. Org. Chem. 2025, 21, 884–889, doi:10.3762/bjoc.21.72

• . Synthesis of ultracycles. Supporting Information Supporting Information File 4: Experimental details and characterization data (including 1H NMR, 13C NMR, IR, and HRMS of precursor compounds and ultracycles, X-ray data for B4aH, theoretical calculations, and NMR titration data). Funding Financial support

4-(1-Methylamino)ethylidene-1,5-disubstituted pyrrolidine-2,3-diones: synthesis, anti-inflammatory effect and in silico approaches

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Luc Van Meervelt,
• Do Thi Thao and
• Nguyen Minh Thong

Beilstein J. Org. Chem. 2025, 21, 817–829, doi:10.3762/bjoc.21.65

• ). Furthermore, the 2D 1H–13C HMBC NMR spectrum of 5a also exhibited the correlation between protons of two methyl groups and the same carbon atom resonance at 165.52 ppm, respectively (see Supporting Information File 1). Consequently, the signal at 165.52 ppm in the 13C NMR spectrum corresponds to the sp2

Development and mechanistic studies of calcium–BINOL phosphate-catalyzed hydrocyanation of hydrazones

• Carola Tortora,
• Christian A. Fischer,
• Sascha Kohlbauer,
• Alexandru Zamfir,
• Gerd M. Ballmann,
• Jürgen Pahl,
• Sjoerd Harder and
• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2025, 21, 755–765, doi:10.3762/bjoc.21.59

• that silicon is bound via the carbonyl oxygen in 12, as also shown by DFT computations. This is further corroborated by observation of a 13C NMR signal at 146 ppm for an sp2 carbon in the backbone of the product, which fits better for a C=N than a C=O bond. Recovery of the catalyst resting state 7 is

• , 13C, and 31P NMR as well as mass-spectrometric data of all synthesized compounds and selected crystal structures. Acknowledgements Portions of this work are included in the doctoral thesis of Christian Andreas Fischer, “Insights in Group 2 Metal Catalysis: New Ways and New Obstacles”, Friedrich

Orthogonal photoswitching of heterobivalent azobenzene glycoclusters: the effect of glycoligand orientation in bacterial adhesion

• Leon M. Friedrich and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2025, 21, 736–748, doi:10.3762/bjoc.21.57

• functionalization of the ABF4 unit. The EE/ZE/EZ/ZZ isomeric mixture obtained after irradiation of the homobivalent photoswitchable glycocluster 6αMan3αMan 2 had to be determined by integration of the anomeric 1H/13C cross peak of the scaffold mannoside in the 1H,13C HSQC spectrum because the proton signals in the

• 1H NMR spectrum are not clearly separated (cf. Supporting Information File 1, Figure S3). This procedure was published earlier for the heterobivalent glycocluster 1 [24], however, in comparison to 1, the anomeric 1H/13C cross peaks of the EE, ZE, EZ, and ZZ isomers of 2 are less well resolved and

• ratios of the individual glycoazobenzene antennas in 2 could be accurately determined by integration of the respective peaks in the 1H,13C HSQC spectrum, namely the anomeric 1H’/13C’ and 1H’’/13C’’ cross peaks (Table 1 and Supporting Information File 1, Figures S4–S6). Comparison of the data collected in

Synthesis of HBC fluorophores with an electrophilic handle for covalent attachment to Pepper RNA

• Raphael Bereiter and
• Ronald Micura

Beilstein J. Org. Chem. 2025, 21, 727–735, doi:10.3762/bjoc.21.56

• column chromatography was purchased from Macherey-Nagel. 1H and 13C NMR spectra were recorded on a Bruker UltrashieldTM 400 MHz Plus or a 700 MHz Avance Neo spectrometer. Chemical shifts (δ) are reported relative to tetramethylsilane (TMS), referenced to the residual solvent signal (DMSO-d6: 2.50 ppm for

• 1H NMR and 39.52 ppm for 13C NMR spectra; CDCl3: 7.26 ppm for 1H NMR and 77.16 ppm for 13C NMR spectra). Signal assignments are based on 1H-1H-COSY, 1H-13C-HSQC and 1H-13C-HMBC experiments. High-resolution mass spectra were recorded in positive ion mode unless otherwise noted on a Thermo Scientific Q

Acyclic cucurbit[n]uril bearing alkyl sulfate ionic groups

• Christian Akakpo,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 717–726, doi:10.3762/bjoc.21.55

• (Figure 2a). The 4.0–4.5 ppm region is crowded which precludes precise assignments of the expected resonances for He, Hg, Hi, Hb, and Hc. Similarly, the 13C NMR spectrum recorded for C1 (Figure 2b) shows 15 of the 16 resonances expected based on time averaged C2v-symmetry in solution. For example, we

• and 150 or 100 MHz for 13C. Melting points were measured on a Meltemp apparatus in open capillary tubes and are uncorrected. IR spectra were measured on a Thermo Nicolet NEXUS 670 FT/IR spectrometer by attenuated total reflectance (ATR) and are reported in cm−1. Mass spectrometry was performed using a

• (d, J = 8.9 Hz, 2H), 5.41 (d, J = 16.3 Hz, 4H), 4.45–4.40 (m, 4H), 4.35–4.30 (m, 4H), 4.27 (d, J = 15.8 Hz, 2 × 4H), 4.25–4.18 (m, 4H), 4.18–4.13 (m, 4H), 4.12 (d, J = 15.4 Hz, 2H), 1.78 (s, 6H), 1.75 (s, 6H); 13C NMR (100 MHz, D2O/acetone-d6 6:1 (v:v)) 156.7, 155.9, 150.5, 129.3, 116.1, 78.6, 77.4

Photochemically assisted synthesis of phenacenes fluorinated at the terminal benzene rings and their electronic spectra

• Yuuki Ishii,
• Minoru Yamaji,
• Fumito Tani,
• Kenta Goto,
• Yoshihiro Kubozono and
• Hideki Okamoto

Beilstein J. Org. Chem. 2025, 21, 670–679, doi:10.3762/bjoc.21.53

• spectra of the fluorescence, synthetic procedures and physical data for the new compounds, theoretical calculation results, copy of 1H and 13C NMR spectra of the prepared compounds. Acknowledgements HO thanks Prof. Kan Wakamatsu (Okayama University of Science) for fruitful discussions and Prof. Takayoshi

Asymmetric synthesis of fluorinated derivatives of aromatic and γ-branched amino acids via a chiral Ni(II) complex

• Maurizio Iannuzzi,
• Thomas Hohmann,
• Michael Dyrks,
• Kilian Haoues,
• Katarzyna Salamon-Krokosz and
• Beate Koksch

Beilstein J. Org. Chem. 2025, 21, 659–669, doi:10.3762/bjoc.21.52

• Schlenk vessels at a Schlenk unit/oil pump vacuum under nitrogen atmosphere. The stated reaction temperatures are the respective values of the silicone oil heating bath. All reactions were stirred with an electric magnetic stirrer. 1H, 13C, and 19F NMR spectra were measured at room temperature with a JEOL

• ECP 600 (JEOL, Tokyo, Japan) device. MestReNova Version 10.0.0 (Mestrelab Research S. L., Santiago de Compostela, Spain) was used to analyze the respective spectra. The chemical shifts are given in parts per million (ppm). The 1H and 13C NMR chemical shifts were referenced against the specific

• = 11.0, 5.9 Hz, 1H), 1.65 (m, 1H); 13C NMR (151 MHz, CDCl3) δ 180.1, 176.4, 171.6, 144.7, 141.1, 134.9 (2C), 133.8, 133.7 (2C), 133.6, 133.1, 132.5, 132.2 (2C), 131.3, 130.9, 130.1, 129.8, 129.6, 127.5 (2C), 127.3 (2C), 127.3, 126.1, 124.4 (2C), 71.5, 68.3, 63.2, 58.7, 31.0, 29.1, 23.9; 19F NMR (565 MHz

Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities

• Rémy B. Teponno,
• Sara R. Noumeur and
• Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48

• massarilactone D, signals of two methacryloyl moieties were depicted in its 1H NMR spectrum at δH 1.92 (s, Me-2''), 1.89 (s, Me-2'''), 6.24 (dq, J = 2.1, 1.0 Hz, Ha-3''), 6.18 (dq, J = 2.2, 1.0 Hz, Ha-3'''), 5.80 (p, J = 1.6 Hz, Hb-3'''), and 5.73 (p, J = 1.6 Hz, Hb-3'') [17]. In the 13C NMR spectrum, the

• (C-1''') and 166.4 (C-1''), respectively, revealed that the two methacryloyl moieties were linked at C-2 and C-3. The other salient feature of the 13C NMR spectrum was the presence of some signals at δC 171.7 (C-1'), 82.3 (C-2'), 31.4 (C-3'), 26.0 (C-4'), 105.1 (C-5'), 137.0 (C-6'), 25.1 (Me-2'), and

• '''), and 6.58 (d, J = 16.0 Hz, H-2''). In the 13C NMR spectrum, the cinnamoyl moieties were evidenced by signals observed at δC 165.9 (C-1''), 165.7 (C-1'''), 147.4 (C-3''), 147.0 (C-3'''), 135.3 (C-4''), 135.2 (C-4'''), 131.7 (C-7'', C-7'''), 130.0 (C-6'', C-8'', C-6''', C-8'''), 129.4 (C-5'', C-9

Sequential two-step, one-pot microwave-assisted Urech synthesis of 5-monosubstituted hydantoins from L-amino acids in water

• Wei-Jin Chang,
• Sook Yee Liew,
• Thomas Kurz and
• Siow-Ping Tan

Beilstein J. Org. Chem. 2025, 21, 596–600, doi:10.3762/bjoc.21.46

• ), 4.33 (td, J = 5, 1 Hz, 1H), 2.92 (m, J = 5 Hz, 2H); 13C NMR (100 MHz, DMSO-d6) δ 175.2, 157.2, 135.6, 129.8, 128.1, 126.7, 58.4, 36.4; LC–MS (ESI) m/z: 191 [M + H]+, 163, 120; HRMS (ESI) m/z: [M + H]+ calcd for C10H11N2O2 191.0815; found, 191.0815. The procedure was repeated by substituting ʟ

• ) δ 10.59 (s, 1H), 7.88 (s, 1H), 7.74 (s, 1H), 6.88 (s, 1H), 5.52 (s, 2H), 4.25 (t, J = 6 Hz, 1H), 2.95 (dd, J = 15, 4 Hz, 1H), 2.81 (dd, J = 15, 6 Hz, 1H); 13C NMR (100 MHz, DMSO-d6) δ 175.5, 157.4, 134.6, 131.6, 117.0, 57.6, 28.8; LC–MS (ESI) m/z: 181 [M + H]+, 136. The procedure was repeated by

• substituting ʟ-histidine with the corresponding amino acid to obtain H2g–j. Hydantoins (H2a–j) synthesized from the one-pot procedure. The hydantoins were characterized using 1H and 13C NMR and HRMS. N-Carbamylation of ʟ-phenylaniline using KOCN in water. One-pot microwave-assisted synthesis of hydantoins from

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

• , 13C NMR spectroscopy and high-resolution MS. 1H NMR spectra of obtained products contain characteristic signals of the protons of the methyl group in the region δ 1.72–2.16 ppm and proton of pyranone fragment in the region δ 5.98–6.62 ppm. Besides that, the key structures of synthesized products were

Vinylogous functionalization of 4-alkylidene-5-aminopyrazoles with methyl trifluoropyruvates

• Judit Hostalet-Romero,
• Laura Carceller-Ferrer,
• Gonzalo Blay,
• Amparo Sanz-Marco,
• José R. Pedro and
• Carlos Vila

Beilstein J. Org. Chem. 2025, 21, 533–540, doi:10.3762/bjoc.21.41

• copies of 1H NMR and 13C NMR spectra. Acknowledgements Access to NMR, MS, and X-ray facilities from the Servei Central de Suport a la Investigació Experimental (SCSIE)-UV and the NMR U26 facility of ICTS “NANBIOSIS” is acknowledged. Funding L.C.-F. thanks the Universitat de València for a predoctoral

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

• )-10. Synthesis of the aggregation pheromone of Tribolium castaneum. Supporting Information Supporting Information File 6: General information, synthesis of compounds 1–12, research on the optical purity of chiral alcohols (R)- and (S)-4, and copies of 1H, 13C and 19F NMR spectra. Funding This

Organocatalytic kinetic resolution of 1,5-dicarbonyl compounds through a retro-Michael reaction

• James Guevara-Pulido,
• Fernando González-Pérez,
• José M. Andrés and
• Rafael Pedrosa

Beilstein J. Org. Chem. 2025, 21, 473–482, doi:10.3762/bjoc.21.34

• substituents present in the starting Michael adducts. Furthermore, it has been observed that the enantioselectivity of Michael adducts decreases with time in the presence of a catalyst derived from diarylprolinol. Experimental General Information 1H NMR (400 or 500 MHz) and 13C NMR (100 MHz) spectra were

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

• tautomeric forms. To reveal the predominance of either the (NH) or (OH) tautomeric form of compounds 7a, 7b, 8a, and 8b in solution depending on the nature of the solvent, we carried out a detailed study using compound 7a. A complete signal assignment of 1H and 13C NMR spectra was carried out, based on

• characteristic values of chemical shifts and cross-peak analysis in two-dimensional spectra of 1H,1H COSY correlations, as well as 1H,13C correlations HSQC, HMBC, and 1H,15N HMBC spectra in DMSO-d6 and CDCl3 (Supporting Information File 2). In the 1H NMR spectrum of 7a in DMSO-d6, the signal of the weak field

• ,15N HMBC spectrum of 7a there are cross peaks of the indolenine nitrogen atom at 162.2 ppm with a weak field proton at δH 14.23 ppm, as well as aromatic protons H(4') and H(5') with δH 7.94 ppm and 7.97 ppm, respectively (Supporting Information File 2, Figure S19). In the two-dimensional 1H,13C HMBC

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

• oxygen atom [50]. Preferential N-alkylation (over O-alkylation) of 1,2-benzothiazine scaffolds has also been carried out by Ahmad and co-workers in 2014 and Szczęśniak-Sięga and companions in 2018 [37][51]. Structure elucidation of all the synthesized derivatives was carried out using 1H, 13C NMR, and

• compounds 7a–h and 7i–n shared a singlet for the N-methyl protons in the range of 3.07 to 3.10 ppm. Signals for aromatic protons were recorded from 6.70 to 8.19 ppm depending upon the extent of shielding/deshielding. The 13C NMR spectra exhibited distinct signals for the synthesized compounds 7a–h: one

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

• data, they luminesce in DMSO solution when irradiated with light at wavelengths of 352 and 283 nm. Compounds 7a–f are capable of existing as lactim–lactam tautomers due to the presence of an amide fragment in their structure (Scheme 7). At the same time, the 1H and 13C NMR spectra of compounds 7a–f

• indicate their individuality. The presence of a broadened signal in the 1H NMR spectra (DMSO-d6) in the region of 12.49–12.84 ppm and a C4 signal in the 13C NMR spectra (DMSO-d6) in the region of 158.1–159.0 ppm does not allow us to unambiguously determine the tautomeric form of compounds 7a–f in solution

• = 10−5 mol/L). 1Н, 13С{1H}, 1H-13C HMQC, and 1H-13C HMBC NMR spectra were registered on a Jeol ECX–400A instrument at 400 (for 1H nuclei) and 100 MHz (for 13С nuclei) in CDCl3 (δH 7.26, δC 77.16 ppm) and DMSO-d6 (δH 2.47, δC 40.0 ppm) using residual signals of the nondeuterated solvent as the

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

• that it is a related derivative to two yellow pyridone pigments, farinosones A and B, that were previously reported from Cordyceps farinosa syn. Paecilomyces farinosus [8][9]. A detailed comparison of the 1H and 13C NMR data of 1 and farinosones A/B revealed that instead of a deshielded pyridone

• ), 300 (0.5), 265 (0.6) 218 (2.4); NMR data (1H: 500 MHz, 13C: 125 MHz, DMSO-d6) see Table 1; HRESIMS m/z: [M – H2O + H]+ calcd for C25H28NO4+, 406.2026; found, 406.2020; [M + H]+ calcd for C25H30NO5+, 424.2118; found, 424.2126; [M + Na]+ calcd for C25H29NNaO5+, 446.1962; found, 446.1947. Farinosone A (2

• ): Pale yellow amorphous solid; UV–vis (MeOH) λmax: 368, 224, 200 nm; NMR data (1H: 500 MHz, 13C: 125 MHz, acetone-d6) comparable to the previously described spectral data [8]; HRESIMS m/z: [M + H]+ calcd for C25H28NO4+, 406.2103; found, 406.2103. Farinosone B (3): Bright yellow powder; UV–vis (MeOH) λmax

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

• 2390715), 7a (CCDC 2390716) and 8a (CCDC 2390717) have been deposited at the Cambridge Crystallographic Database Center. Supporting Information File 2: Experimental procedures, 1H, 13C NMR, and HRMS spectra for all new compounds. Funding This work was financially supported by the National Natural Science

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

• UV lamp. 1H and 13C NMR spectra were recorded on Bruker Avance and Agilent 400-MR spectrometers (400 MHz for 1H, 100 MHz for 13C). Chemical shifts are reported in ppm relative to TMS. General procedure for the three-component reactions under diffusion mixing conditions A mixture of 1.0 mmol CH acid

• , CDCl3, δ) 7.98–7.89 (m, 4H), 7.45–7.38 (m, 2H), 7.36–7.28 (m, 4H), 6.30 (dd, J = 5.7, 3.0 Hz, 1H), 5.74 (dd, J = 5.7, 2.9 Hz, 1H), 3.94–3.90 (m, 1H), 3.00–2.95 (m, 1H), 2.84 (dd, J = 12.1, 2.9 Hz, 1H), 2.18 (dd, J = 12.1, 3.7 Hz, 1H), 1.76–1.71 (m, 1H), 1.63–1.54 (m, 1H); 13C NMR (101 MHz, CDCl3, δ

• ), 6.22–6.16 (m, 1H), 6.09–6.04 (m, 1H), 5.44–5.39 (m, 1H), 3.18–3.08 (m, 1H), 2.75 (dd, J = 14.3, 6.1 Hz, 1H), 2.71–2.62 (m, 1H), 2.58 (dd, J = 14.3, 4.8 Hz, 1H), 2.34–2.25 (m, 1H); 13C NMR (101 MHz, CDCl3, δ) 198.4, 165.1, 139.1, 137.5, 135.6, 131.4, 130.9, 129.7 (2C), 129.6 (2C), 129.5 (2C), 127.7 (3C

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

• by distillation before use. 1H NMR (300 MHz) and 13C NMR (75 MHz) spectra were recorded on a Bruker AV-300N spectrometer with tetramethylsilane (TMS) as the internal standard. High-resolution mass spectra (HRMS) were measured on a JEOL AccTOF LC mass spectrometer. UV–vis absorption spectra were

• , 3H, CH3), 7.45–7.50 (m, 3H, aromatic H), 7.93–7.97 (m, 2H, aromatic H); 13C NMR (75 MHz, CDCl3) δ = 17.25, 17.31, 111.87, 126.93, 129.29, 131.31, 132.62, 157.67, 171.07, 171.09; HRMS–DART+ (m/z): [M + H]+ calcd for C15H9F7NS+, 368.0344; found, 368.0350. 3-Methyl-2-(perfluorocyclopent-1-en-1-yl

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

• important in pharmaceuticals and agrochemicals [41][42][43][44][45][46][47], we expect that this method will provide a novel and efficient approach for producing these valuable compounds. Experimental General: 1H NMR, 13C NMR, 19F NMR, and 31P NMR were recorded on a Bruker Avance 500 or a JEOL ECS-400

• spectrometer. Chemical shift values are given in ppm relative to internal Me4Si (for 1H NMR: δ = 0.00 ppm), CDCl3 (for 13C NMR: δ = 77.0 ppm), C6F6 (for 19F NMR: δ = 0.0 ppm), and H3PO4 (for 31P NMR: δ = 0.0 ppm). IR spectra were recorded on a Horiba FT-730 spectrometer. Mass spectra were measured on a JEOL

• Hz, 1H), 7.49–7.46 (m, 2H), 7.35 (dd, J = 7.7, 7.6 Hz, 1H), 7.16 (d, J = 7.6 Hz, 1H), 2.44 (s, 3H); 13C NMR (126 MHz, CDCl3) δ 155.6, 152.3, 138.5, 130.5, 130.4, 129.1, 128.8, 128.7, 127.6, 126.2, 125.3, 125.1, 124.6, 124.5, 123.4, 121.9, 112.3, 100.3, 21.5; IR (KBr): 3051, 1606, 1487, 1387, 1280

Facile one-pot reduction of β-nitrostyrenes to phenethylamines using sodium borohydride and copper(II) chloride

• Laura D’Andrea and
• Simon Jademyr

Beilstein J. Org. Chem. 2025, 21, 39–46, doi:10.3762/bjoc.21.4

• aromatic compounds. Experimental NMR spectra were recorded on Bruker Avance 400 MHz or Bruker Avance III HD 600 MHz spectrometers. Residual solvent peaks (CDCl3, D2O, CD3OD, (CD3)2SO) were used as internal standard (7.26, 4.79, 3.31, and 2.50 ppm for 1H, and 77.16, 49, and 39.52 ppm for 13C, respectively

• hydrochloride (1b): The product was isolated by use of (II) as an amorphous white solid (83%). 1H NMR (600 MHz, CD3OD) δ 2.97 (m, J = 5.18 Hz, 2H), 3.18 (m, J = 5.24 Hz, 2H), 7.28 (m, J = 5.0 Hz, 3H), 7.35 (m, J = 7.6 Hz, 2H); 13C NMR (151 MHz, CD3OD) δ 34.55, 41.98, 128.26, 129.77, 129.99, 137.92; ESI-MS m/z

• , J = 8.4, 2.5, 0.2 Hz, 2H); 13C NMR (151 MHz, CD3OD) δ 33.75, 42.14, 55.71, 115.42, 129.60, 130.78, 160.47; ESI-MS m/z: [M + 1]+ 151.1; found, 152.1; mp 214–216 °C. 1-(2,5-Dimethoxyphenyl)propan-2-amine hydrochloride (3b): The product was isolated by use of (II) as a white solid (62%). 1H NMR (600