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

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

• (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

• , 71.2, 69.5, 67.4, 52.5, 48.4, 35.0, 16.3, 15.4 ppm; ESIMS (m/z): 751.13 ([M − 2Na]2−), calcd for [C50H56N16Na2S4O28]2−, 751.1064. Chemical structures of CB[n] and selected acyclic CB[n]-type molecular containers M1 and M0. a) 1H NMR spectrum (600, D2O, rt) and b) 13C NMR spectrum recorded (150 MHz, D2O

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

• 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

• , 1H), 2.45–2.34 (m, 1H), 2.07–2.01 (m, 1H), 1.99 (dt, J = 11.1, 5.4 Hz, 1H); 13C NMR (151 MHz, CDCl3) δ 180.1, 177.4, 171.4, 141.3, 138.3, 134.9, 133.8, 133.7, 133.5, 133.1, 133.1, 132.4, 132.1, 131.9, 131.2, 130.9, 130.1, 130.0, 129.9, 129.6, 127.5, 127.3, 126.9, 126.0, 124.3 (2C), 124.1, 122.3

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

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

• CH3CN.a Supporting Information Supporting Information File 11: Experimental procedures and characterization data for all novel compounds 7a, 7b, 8a and 8b. Supporting Information File 12: 1H, 13C NMR, IR and HRMS spectra of all novel compounds. Supporting Information File 13: X-ray analysis data of 7b

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

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

• with farinosones D (1) and A (2), microporenic acid A (MAA) as a positive control and methanol as a solvent control and taken as 100%. 1H and 13C NMR data of farinosone D (1). Cytotoxicity (IC50) and antimicrobial activity (MIC) of 1–6. Inhibition of biofilm formation of S. aureus by 1 and 2

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

• 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

• MHz, CD3OD) δ 1.26 (d, J = 6.60 Hz, 3H), 2.82 (m, J = 6.92 Hz, 1H), 2.95 (m, J = 6.60 Hz, 1H), 3.56 (m, J = 6.51 Hz, 1H), 3.75 (s, 3H), 3.81 (s, 3H), 6.79 (m, J = 2.94 Hz, 1H), 6.84 (dd, J = 2.43, 8.85 Hz, 1H), 6.93 (m, J = 8.94 Hz, 1H); 13C NMR (151 MHz, CD3OD) δ 18.56, 36.85, 49.22, 56.12, 56.24

Synthesis, structure and π-expansion of tris(4,5-dehydro-2,3:6,7-dibenzotropone)

• Yongming Xiong,
• Xue Lin Ma,
• Shilong Su and
• Qian Miao

Beilstein J. Org. Chem. 2025, 21, 1–7, doi:10.3762/bjoc.21.1

• . This corresponds to a molecular formula of C119H122O9, which is in agreement with the fully fused product 11 in its protonated form. Unfortunately, clean 1H and 13C NMR spectra of this product could not be obtained to allow full characterization of this product. Efforts to increase the yield of 11

Giese-type alkylation of dehydroalanine derivatives via silane-mediated alkyl bromide activation

• Perry van der Heide,
• Michele Retini,
• Fabiola Fanini,
• Giovanni Piersanti,
• Francesco Secci,
• Daniele Mazzarella,
• Timothy Noël and
• Alberto Luridiana

Beilstein J. Org. Chem. 2024, 20, 3274–3280, doi:10.3762/bjoc.20.271

• nm, 25 °C, overnight. The yield of 3 was calculated by 1H NMR with 1,1,2-trichloroethene as external standard. Supporting Information Supporting Information File 52: 1H NMR, 13C NMR, and HRMS spectra of all the synthesized compounds. Acknowledgements We are grateful to University Research Services

Ceratinadin G, a new psammaplysin derivative possessing a cyano group from a sponge of the genus Pseudoceratina

• Shin-ichiro Kurimoto,
• Kouta Inoue,
• Taito Ohno and
• Takaaki Kubota

Beilstein J. Org. Chem. 2024, 20, 3215–3220, doi:10.3762/bjoc.20.267

• existence of a substituted benzenoid chromophore was suggested by the UV absorption maximum at 258 nm. The presence of hydroxy and/or amino groups and a carbonyl group was indicated by IR absorptions at 3337 cm−1 and 1671 cm−1, respectively. The analysis of the HSQC spectrum, along with the 1H and 13C NMR

• (partial structures a and b, respectively, in Figure 2), which were characteristic of psammaplysins, in ceratinadin G (1) was suggested by comparison of its 1H and 13C NMR data with those of known psammaplysin derivatives such as psammaplysins A and F (2) [4][5][6][10][11][12]. HMBC correlations (H-1/C-2

• 116.9) and the molecular formula of compound 1, it was inferred that a cyano group is attached to C-22. The 13C NMR chemical shifts of C-22 and C-23 closely matched those of the corresponding carbons in known synthetic compounds with an aminoacetonitrile moiety, further supporting the presence of a

Discovery of ianthelliformisamines D–G from the sponge Suberea ianthelliformis and the total synthesis of ianthelliformisamine D

• Sasha Hayes,
• Yaoying Lu,
• Bernd H. A. Rehm and
• Rohan A. Davis

Beilstein J. Org. Chem. 2024, 20, 3205–3214, doi:10.3762/bjoc.20.266

• protons indicating the presence of a symmetrical aromatic moiety, were observed. The 13C NMR (Table 1) spectrum of 4 showed two carbonyls (δC 164.4, 173.9), with the carbonyl at δC 164.4 readily assigned to an acrylamide group, which is present in all previously published ianthelliformisamine molecules [7

• ]. The 13C NMR (Table 1) data of 5 displayed six aliphatic carbons (δC 35.9, 26.1, 44.8, 46.3, 21.1, 30.4) and two carbonyl signals (δC 164.9, 173.6). Similarly to the other ianthelliformisamines, the aromatic (δC 131.6) and olefin (δC 124.5, 135.2) carbons were observed [7]. COSY correlations associated

• carbon signal. Although a downfield exchangeable CO2H proton was not observed in the 1H NMR spectrum of 5, a carboxylic acid moiety was assigned based on the 13C NMR shift value (δC 173.6) [17], and analysis of the HRESIMS ion at m/z 477.0022 [M + H]+, which confirmed the molecular formula to be

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