Investigation of a bimetallic terbium(III)/copper(II) chemosensor for the detection of aqueous hydrogen sulfide

• Parvathy Mini,
• Michael R. Grace,
• Genevieve H. Dennison and
• Kellie L. Tuck

Beilstein J. Org. Chem. 2024, 20, 2818–2826, doi:10.3762/bjoc.20.237

• magnetic resonance (1H NMR) spectra was recorded on a Bruker DRX400 spectrometer operating at 400 MHz. High-resolution mass spectrometry (HRMS) was performed using a Bruker BioApex 47e FTMS with an analytical electrospray source employing NaI for accurate mass calibration (ESI). UV–vis absorption spectra

Synthesis of spiroindolenines through a one-pot multistep process mediated by visible light

• Francesco Gambuti,
• Jacopo Pizzorno,
• Chiara Lambruschini,
• Renata Riva and
• Lisa Moni

Beilstein J. Org. Chem. 2024, 20, 2722–2731, doi:10.3762/bjoc.20.230

• analyses were performed by using the ionization method ESI+ with a 6230 TOF LC/MS, Agilent Technologies. Unless otherwise noted, analytical grade solvents and commercially available reactants were used without further purification. Common reagents were purchased from commercial sources and were used

• ), 103.5 (CH Ar), 75.9 (Cq spiro), 55.4 (OCH3), 52.1 (Cq t-Bu), 47.9 (CH2), 30.9 (CH2), 28.5 (3 CH3 of t-Bu); HRMS (ESI+) (m/z) [M + H]+: calcd for C27H30N3O, 412.238; found, 412.2395. Selected natural products containing spiro-indolenines. Time profile of the reaction of N-Ph-THIQ, 3,5-dimethoxyaniline

Synthesis of benzo[f]quinazoline-1,3(2H,4H)-diones

• Ruben Manuel Figueira de Abreu,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2708–2719, doi:10.3762/bjoc.20.228

• preceding gas chromatograph (GC) or liquid chromatograph (LC). Samples were ionised by electron impact ionisation (EI) on an Agilent 6890/5973 or Agilent 7890/5977 GC–MS equipped with an HP-5 capillary column using helium carrier gas or by electron spray ionisation (ESI) on an Agilent 1200/6210 Time-of

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

• solvent signals (DMSO-d6: 2.50 ppm (1H NMR) and 39.52 ppm (13C NMR)). High-resolution mass spectra (HRMS) were obtained on a Bruker micrOTOF II instrument using electrospray ionization (ESI). The melting points were determined on a Kofler hot stage apparatus. A magnetic stirrer IKA C-MAG HS 7 was used for

• (75 MHz, DMSO-d6) δ 178.2, 175.5, 164.8, 138.1, 128.9, 128.3, 126.4, 98.7, 44.3, 44.0, 39.4, 32.6, 32.1, 24.7, 23.9, 21.9; HRMS (ESI-TOF) m/z: [M + H]+ calcld for C23H26NO5, 396.1805; found, 396.1801. Analytical data of further synthesized compounds can be found in Supporting Information File 2

• Hz, 2H), 1.63–1.53 (m, 2H), 1.40–1.11 (m, 5H); 13C NMR (75 MHz, DMSO-d6) δ 179.8, 175.3, 164.8, 140.4, 138.4, 129.0, 128.4, 128.3, 126.3, 88.98, 43.7, 43.5, 39.7, 32.8, 32.3, 24.9, 22.0, 12.8; HRMS (ESI-TOF) m/z: [M + H]+ calcld for C23H28N3O4, 410.2074; found, 410.2092. Experimental procedure for

Asymmetric organocatalytic synthesis of chiral homoallylic amines

• Nikolay S. Kondratyev and
• Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

• two enantiotopic faces of acylimine 2, exposing only one face to the attack by the allyl group. The replacement of one isopropoxy (iPrO) group between allylboronate 1 with BINOL was confirmed by ESI-MS and NMR analysis of the reaction mixture. Interestingly, both (E)- and (Z)-crotyl boronates 6 and 8

Selective hydrolysis of α-oxo ketene N,S-acetals in water: switchable aqueous synthesis of β-keto thioesters and β-keto amides

• Haifeng Yu,
• Wanting Zhang,
• Xuejing Cui,
• Zida Liu,
• Xifu Zhang and
• Xiaobo Zhao

Beilstein J. Org. Chem. 2024, 20, 2225–2233, doi:10.3762/bjoc.20.190

• were recorded on a Bruker DRX-600 spectrometer and all chemical shift values are referenced to TMS (δ = 0.00 ppm for 1H) and CDCl3 (δ = 77.16 ppm for 13C). HRMS analysis was achieved with a Bruck microTof using the ESI method. All melting points are uncorrected. Analytical TLC plates (Sigma-Aldrich

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

• spectra were acquired on Bruker 300 MHz spectrometers equipped with 5 mm BBFO probes. HRMS data were acquired using an Agilent 6530 LC/Q-TOF using a Dual AJS/ESI ion source, and the isotope 79 was used for HRMS analysis for any bromine-containing compounds. Synthesis All procedures and spectra can be

Discovery of antimicrobial peptides clostrisin and cellulosin from Clostridium: insights into their structures, co-localized biosynthetic gene clusters, and antibiotic activity

• Moisés Alejandro Alejo Hernandez,
• Katia Pamela Villavicencio Sánchez,
• Rosendo Sánchez Morales,
• Karla Georgina Hernández-Magro Gil,
• David Silverio Moreno-Gutiérrez,
• Eddie Guillermo Sanchez-Rueda,
• Yanet Teresa-Cruz,
• Brian Choi,
• Armando Hernández Garcia,
• Alba Romero-Rodríguez,
• Oscar Juárez,
• Siseth Martínez-Caballero,
• Mario Figueroa and
• Corina-Diana Ceapă

Beilstein J. Org. Chem. 2024, 20, 1800–1816, doi:10.3762/bjoc.20.159

• presented (right). The highlighted cluster was chosen for heterologous expression. A. Similarity network created with the ESI web tool with the precursor peptide amino acid sequences. In the similarity network of precursor peptides, each blue node represents a characterized lanthipeptide, and each pink node

Oxidation of benzylic alcohols to carbonyls using N-heterocyclic stabilized λ³-iodanes

• Thomas J. Kuczmera,
• Pim Puylaert and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2024, 20, 1677–1683, doi:10.3762/bjoc.20.149

• -activated iodane of this type, a mixture of NHI 1a and HCl in EtOAc was stirred for 1 h at 60 °C and an ESI(−) mass spectrum was recorded afterward, showing an ion I-OMe with m/z 337.0 [1a – OH + MeO + Cl]− (Scheme 1c). It is known that methanol, which is used as a solvent in the mass spectrometer, can be

• species in the ESI(−) MS. Varying the additive and solvent in the oxidation of electron-rich and electron-deficient benzylic alcohols with 1a.a Testing different NHIs under the optimum conditions for oxidation of electron-deficient substrate 3b.a Supporting Information Supporting Information File 6

Tetrabutylammonium iodide-catalyzed oxidative α-azidation of β-ketocarbonyl compounds using sodium azide

• Christopher Mairhofer,
• David Naderer and
• Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1510–1517, doi:10.3762/bjoc.20.135

• were recorded on an Agilent QTOF 6520 spectrometer with an ESI source. Melting points are recorded using a Büchi M-560 apparatus and are reported uncorrected. TLC was performed on Macherey-Nagel pre-coated TLC plates (silica gel, 60 F254, 0.20 mm, ALUGRAM® Xtra SIL). Preparative column chromatography

• , 1271, 1259, 1215, 1145, 1091, 1054, 1027, 961, 913, 871, 844, 834, 818, 804, 756, 729, 711, 688, 661, 623, 598, 561, 533, 459, 416; HRMS (ESI+-QqTOF, m/z): [M + NH4]+ calcd for C14H19N4O3, 291.1452; found, 291.1452 (major); TLC (silica gel K60, 200 µm, F254, heptanes/EtOAc = 7:3, 298 K, Rf 0.64; mp

• , 1589, 1548, 1465, 1431, 1396, 1371, 1353, 1325, 1272, 1260, 1215, 1145, 1091, 1056, 1026, 961, 912, 871, 844, 834, 818, 803, 755, 730, 711, 688, 661, 625, 598, 561, 533, 459, 414; HRMS (ESI+-QqTOF, m/z): [M + H]+ calcd for C14H16NO5, 278.1023; found, 278.1024; TLC (silica gel K60, 200 µm, F254

Kinetically stabilized 1,3-diarylisobenzofurans and the possibility of preparing large, persistent isoacenofurans with unusually small HOMO–LUMO gaps

• Qian Liu and
• Glen P. Miller

Beilstein J. Org. Chem. 2024, 20, 1099–1110, doi:10.3762/bjoc.20.97

• spectroscopy. After 51 hours of reaction in boiling CH2Cl2, Diels–Alder adduct 27 was observed in 22% yield. Compound 27 was identified by 1H NMR and 13C NMR spectroscopies as well as high-resolution ESI mass spectrometry. Although the lack of reactivity observed for 3 and 23 limited our kinetic analysis, we

• -dimesityl-1,4-dihydro-1,4-epoxynaphthalene-2,3-dicarboxylate (27). Supporting Information Supporting Information File 24: 1H NMR stability studies for compounds 3 and 23, 1H and 13C NMR spectra for key compounds and ESI high-resolution mass spectra. Funding The authors gratefully acknowledge financial

Structure–property relationships in dicyanopyrazinoquinoxalines and their hydrogen-bonding-capable dihydropyrazinoquinoxalinedione derivatives

• Tural N. Akhmedov,
• Ajeet Kumar,
• Daken J. Starkenburg,
• Kyle J. Chesney,
• Khalil A. Abboud,
• Novruz G. Akhmedov,
• Jiangeng Xue and
• Ronald K. Castellano

Beilstein J. Org. Chem. 2024, 20, 1037–1052, doi:10.3762/bjoc.20.92

• in parts per million (ppm) relative to TMS and referenced to residual protonated solvent (CDCl3: δH 7.26 ppm, δC 77.23 ppm; DMSO-d6: δH 2.50 ppm, δC 39.50 ppm). Abbreviations used are s (singlet), d (doublet), t (triplet), q (quartet), quin (quintet), hp (heptet), b (broad), and m (multiplet). ESI

• - and ESI-TOF-MS spectra were recorded on a Bruker APEX II FTICR and Agilent 6210 TOF spectrometer, respectively. EI-, CI-, and DIP-CI-MS spectra were recorded on a Thermo Trace GC DSQ (single quadrupole) spectrometer. Absorbance measurements Absorbance spectra were measured for 2.5, 5, 10, 15, 20, and

Synthesis and properties of 6-alkynyl-5-aryluracils

• Ruben Manuel Figueira de Abreu,
• Till Brockmann,
• Alexander Villinger,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 898–911, doi:10.3762/bjoc.20.80

• ). Samples were ionized by electron impact ionization (EI) on an Agilent 6890/5973 or Agilent 7890/5977 GC–MS equipped with a HP-5 capillary column using helium carrier gas or by electron spray ionization (ESI) on an Agilent 1200/6210 time-of-flight (TOF) LC–MS. X-ray single-crystal structure analysis was

Activity assays of NnlA homologs suggest the natural product N-nitroglycine is degraded by diverse bacteria

• Kara A. Strickland,
• Brenda Martinez Rodriguez,
• Ashley A. Holland,
• Shelby Wagner,
• Michelle Luna-Alva,
• David E. Graham and
• Jonathan D. Caranto

Beilstein J. Org. Chem. 2024, 20, 830–840, doi:10.3762/bjoc.20.75

• , 4.6 × 150 mm) and connected to an Agilent 6230 TOF mass spectrometer with electrospray ionization (ESI). Analyses used an isocratic mixture containing 65% water, 25% acetonitrile, and 10% isopropanol at a flow rate of 0.5 mL/min. The mass spectrometer was run in the negative ion mode with a probe

Skeletal rearrangement of 6,8-dioxabicyclo[3.2.1]octan-4-ols promoted by thionyl chloride or Appel conditions

• Martyn Jevric,
• Julian Klepp,
• Johannes Puschnig,
• Oscar Lamb,
• Christopher J. Sumby and
• Ben W. Greatrex

Beilstein J. Org. Chem. 2024, 20, 823–829, doi:10.3762/bjoc.20.74

• alkoxytriphenylphosphonium chloride (26, R = Bn), which then slowly rearranged over 24 hours at 83 °C in DCE, eliminating triphenylphosphine oxide (Figure 2). A single ion was observed in the ESI mass spectrum for the intermediate at m/z 571.1 corresponding to the [M + PPh3 − H]+, and in the 1H NMR, the H4 adjacent to the

New variochelins from soil-isolated Variovorax sp. H002

• Jabal Rahmat Haedar,
• Aya Yoshimura and
• Toshiyuki Wakimoto

Beilstein J. Org. Chem. 2024, 20, 692–700, doi:10.3762/bjoc.20.63

• standards (CD3OD: δH 3.31, δC 49.0). LC–MS experiments and ESI–TOF MS/MS analyses were performed with an amaZon SL-NPC (Bruker Daltonics) or LCMS-2020 (Shimadzu) spectrometer coupled with a Shimadzu HPLC system equipped with an LC-20AD intelligent pump. GC–MS experiments were performed with a Shimadzu

Discovery of unguisin J, a new cyclic peptide from Aspergillus heteromorphus CBS 117.55, and phylogeny-based bioinformatic analysis of UngA NRPS domains

• Sharmila Neupane,
• Marcelo Rodrigues de Amorim and
• Elizabeth Skellam

Beilstein J. Org. Chem. 2024, 20, 321–330, doi:10.3762/bjoc.20.32

• and 700 nm. The MS was optimized using the following conditions: interface voltage 4.5 kV; interface temperature 350 °C; DL temperature 250 °C; heat block 200 °C; ESI mode, acquisition range 100 to 1000 Da; nebulizing gas 1.5 L min−1; drying gas flow 15 L min−1. The fractionation of the sample was

Synthesis of the 3’-O-sulfated TF antigen with a TEG-N₃ linker for glycodendrimersomes preparation to study lectin binding

• Mark Reihill,
• Hanyue Ma,
• Dennis Bengtsson and
• Stefan Oscarson

Beilstein J. Org. Chem. 2024, 20, 173–180, doi:10.3762/bjoc.20.17

• electrospray ionisation (ESI) in positive mode. MALDI–TOF mass spectrometry data were recorded on a Scientific Analysis Instruments MALDI–TOF mass spectrometer in reflectron mode for oligosaccharides and in linear mode for glycoconjugates. Samples were prepared by pre-mixing 1 µL of a solution containing the

Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions

• Julika Schlosser,
• Olga Fedorova,
• Yuri Fedorov and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 101–117, doi:10.3762/bjoc.20.11

• (OCH3), 58.2 (OCH3), 100.1 (C10), 110.1 (C7), 121.5 (C5), 124.4 (C6a), 127.3 (C2), 129.8 (C4), 131.9 (C10a), 135.4 (C1), 136.4 (C3), 139.5 (C6), 144.8 (C4a), 153.4 (C8), 156.4 (C9), 164.1 (CO2CH3); MS (ESI+) m/z: [M+] 298 (100); Anal. calcd for C17H16ClNO8·0.5HClO4: C, 45.58; H, 3.71; N, 3.13; found: C

• ), 142.0 (C4a), 153.5 (C8), 156.4 (C9); MS (ESI+) m/z: [M+] 274 (100); HRMS–ESI+ (m/z): [M]+ calcd. for C15H13NO2Cl, 274.0629; found, 274.0625. 2-Ethyl-8,9-dimethoxybenzo[c]quinolizinium perchlorate (3f) According to GP, a solution (c = 0.95 mM) of 2f (102 mg, 379 µmol) in MeCN (400 mL) was irradiated for

• ), 110.0 (C7), 121.5 (C5), 124.0 (C6a), 129.0 (C4), 130.9 (C10a), 131.4 (C1), 136.2 (C6), 139.3 (C3), 141.9 (C4a), 142.1 (C2), 152.9 (C9), 155.7 (C8); MS (ESI+) m/z: [M+] 268 (100); Anal. calcd for C17H18ClNO6: C, 55.52; H, 4.93; N, 3.81; found: C, 55.71; H, 4.89; N, 3.83. 2-Acetylamino-8,9-dimethoxybenzo

Cycloaddition reactions of heterocyclic azides with 2-cyanoacetamidines as a new route to C,N-diheteroarylcarbamidines

• Pavel S. Silaichev,
• Tetyana V. Beryozkina,
• Vsevolod V. Melekhin,
• Valeriy O. Filimonov,
• Andrey N. Maslivets,
• Vladimir G. Ilkin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2024, 20, 17–24, doi:10.3762/bjoc.20.3

• , 135.7, 143.8, 152.3, 152.9, 157.3, 162.4; IR (ATR, KBr, cm−1): ν 3402, 3316, 3201, 1700, 1688, 1649, 1629, 1594, 1568, 1520, 1497, 1476, 1454, 1444, 1426, 1386, 1358, 1335, 1311, 1276, 1264, 1248, 1194, 1090, 1057, 1028; HRMS–ESI-TOF (m/z): [M + H]+ calcd for C16H19N8O2+, 355.1625; found: 355.1628. (Z

• , 174.5; IR (ATR, KBr, cm−1): ν 3400, 3359, 3255, 1625, 1602, 1563, 1554, 1508, 1495, 1483, 1455, 1436, 1425, 1402, 1385, 1356, 1332, 1319, 1303, 1283, 1257, 1215, 1151, 1095, 1067, 1053, 1035, 1011; HRMS–ESI-TOF (m/z): [M + H]+ calcd for C13H14N7S+, 300.1026; found, 300.1031. X-ray structure

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• carbenes with a strong base, followed by their nucleophilic addition onto carbon disulfide. The nine products obtained were characterized by 1H and 13C NMR spectroscopy, FTIR spectroscopy, HR–ESI mass spectrometry, and elemental analysis. Moreover, the molecular structures of two CAAC·CS2 and two MIC·CS2

Construction of diazepine-containing spiroindolines via annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates

• Xing Liu,
• Wenjing Shi,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1923–1932, doi:10.3762/bjoc.19.143

• , 125.5, 117.4, 109.9, 95.0, 52.3, 44.4, 37.0, 20.9 ppm; IR (KBr) ν: 2960, 2936, 2870, 2211, 1717, 1626, 1498, 1445, 1367, 1268, 1193, 1112, 1090, 1009, 903, 868, 815 cm−1; HRMS–ESI TOF (m/z): [M + Na]+ calcd for C34H26N4O2Na, 545.1956; found, 545.1948. General procedure for the preparation of

• , 127.5, 127.0, 124.4, 111.6, 110.4, 52.2, 51.1, 44.4, 36.8 ppm; IR (KBr) ν: 2924, 2853, 1721, 1608, 1484, 1456, 1430, 1340, 1170, 812 cm−1; HRMS–ESI TOF (m/z): [M + H]+ calcd for C34H27ClN3O4, 576.1685; found, 576.1683. General procedure for the preparation of dihydrospiro[indoline-3,5'-[1,2]diazepines

• cm−1; HRMS–ESI TOF (m/z): [M + Na]+ calcd for C34H28ClN4O3SNa, 595.1774; found, 595.1765. The crystallographic data of compound 7a (CCDC 2280223) have been deposited at the Cambridge Crystallographic Database Centre. Single crystal structure of the spiro compound 7a. Representative [4 + 3

Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions

• Karolis Leitonas,
• Brigita Vigante,
• Dmytro Volyniuk,
• Audrius Bucinskas,
• Pavels Dimitrijevs,
• Sindija Lapcinska,
• Pavel Arsenyan and
• Juozas Vidas Grazulevicius

Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139

• (m, 2H), 3.02–2.99 (m, 4H), 1.63–1.51 (m, 6H); MS–ESI− (m/z): 315 ([M − H − piperidine]−, 100). 2,6-Dibromo-4-(4-bromophenyl)pyridine-3,5-dicarbonitrile (3). A mixture of compound 2 (1.16 g, 2.89 mmol, 1 equiv) and POBr3 (2.49 g, 8.68 mmol, 3 equiv) was heated with stirring in an oil bath at 170 °C

• obtained as bright yellow powder. Mp > 200 °C; 1H NMR (400 MHz, CDCl3) 8.10 (d, J = 1.6 Hz, 4H), 7.86 (d, J = 8.5 Hz, 2H), 7.76 (d, J = 8.5 Hz, 2H), 7.71 (d, J = 8.7 Hz, 4H), 7.48 (dd, J = 7.8, 1.9 Hz, 4H), 1.46 (s, 36H); MS–ESI+ (m/z): 839 ([M + H]+, 100); Anal. calcd for C53H52BrN5: C, 75.88; H, 6.25; N

• , 129.64, 127.20, 125.71, 124.18, 116.57, 114.00, 112.34, 103.64, 99.21, 98.30, 34.90, 31.81; MS–ESI+ (m/z): 856 ([M + H]+, 100). Next, potassium carbonate (69 mg, 0.5 mmol, 1 equiv) was added to a solution of 2,6-bis-(3,6-di-tert-butyl-9H-carbazol-9-yl)-4-(4-(trimethylsilylethynyl)phenyl)pyridine-3,5

Substituent-controlled construction of A₄B₂-hexaphyrins and A₃B-porphyrins: a mechanistic evaluation

• Seda Cinar,
• Dilek Isik Tasgin and
• Canan Unaleroglu

Beilstein J. Org. Chem. 2023, 19, 1832–1840, doi:10.3762/bjoc.19.135

• certain time intervals within 2 hours and examined by ESI LC–MS. Throughout the high-resolution electrospray-ionization time-of-flight (HRESI–TOF) mass analysis of the reaction mixture at 0 °C, the following peaks were observed: m/z = 246.0366 ([M + H]+ calcd for C11H5F5N, 246.0337), m/z = 857.1468 ([M

Selectivity control towards CO versus H₂ for photo-driven CO₂ reduction with a novel Co(II) catalyst

• Lisa-Lou Gracia,
• Philip Henkel,
• Olaf Fuhr and
• Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

• high-resolution mass spectrometry (ESI), where it was shown the fragment corresponding to complex 1 that lost one isothiocyanate, [M − NCS]+, as the primary signal. Elemental analysis matched the calculated values, incorporating an additional MeOH molecule. Recrystallization was afforded by re