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

• 1,2-benzoquinone and o-chloroanil, respectively [1][25]. The structures of compounds 7 and 8 obtained by methods A and B were confirmed by 1H NMR, IR spectroscopy and mass spectrometry (Supporting Information File 2). A distinctive feature of the 1H NMR spectra of 7 in CDCl3 is the signal of the

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

• literature. During our attempt to scale up the preparation of BPP 2 through the "DPEX" reaction, we unexpectedly obtained a 5-isopropoxy-substituted derivative of BPP (BPP-OiPr 3) (Scheme 1), whose structure was proven by NMR, mass spectrometry, and X-ray crystallography. In this work, we optimized the

• 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

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

Heteroannulations of cyanoacetamide-based MCR scaffolds utilizing formamide

• Marios Zingiridis,
• Danae Papachristodoulou,
• Despoina Menegaki,
• Konstantinos G. Froudas and
• Constantinos G. Neochoritis

Beilstein J. Org. Chem. 2025, 21, 217–225, doi:10.3762/bjoc.21.13

• methods, synthetic procedures, analytical data and exemplary copies of NMR spectra of novel compounds. Supporting Information File 97: CheckCIF report for 7b. Supporting Information File 98: CIF file for 7b. Acknowledgements We acknowledge the mass spectrometry facility of the University of Crete

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

• supramolecular dimerization was triggered by observations in mass spectrometry experiments when exploring host–guest interactions. Positive-ion electrospray ionization mass spectrometry (ESI(+)MS) of a sample solution of cyclo[6]aramide H1 and a pyridinium derivative G1 in CHCl3/CH3CN (1:1, v/v) showed a

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

• detected [40]. High-resolution mass spectrometry (HRMS) analysis of the reaction mixture also supported the formation of Eb (calcd, 804.4474; found, 804.4449). Additionally, 79% of 1b remained, while the catalytic reaction between 1b and 2a was completed in 13 h, yielding 3ba in 96% (Scheme 2). These

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• porphyrins, and provided evidence for aryl radical formation through mass spectrometry and NMR analysis of the adduct formed from the reaction between the radical intermediate and the scavenger 2,2,6,6-tetramethyl-1-piperidin-1-oxyl (TEMPO). Furthermore, they used the catalysts for borylation of arylamines

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

• understanding of the decomposition mechanism. Despite large differences in Tonset, most samples showed relatively consistent second decomposition steps at ca. 225 °C (Figure 3b), which is indicative of a common decomposition intermediate for all compounds. To investigate this common intermediate, ex-situ mass

• spectrometry (MS) and NMR analysis were carried out on aborted TGA runs of compounds 1e, 1i, 1j and 1k that had been held at a constant temperature T1 (50–140 °C, see Supporting Information File 1) under an N2 atmosphere in open pans for 30 min or until a mass loss >5% of the original mass was observed, then

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

• materials. Supporting Information Supporting Information File 30: NMR spectra of compounds, crystallographic informnation and OFET plots. Acknowledgements We acknowledge EPSRC UK National Mass Spectrometry Facility at Swansea University and EPSRC UK National Crystallography Service. Funding Sondos

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

• mass spectrometry. Taking 4h as an example for the analysis of its structure, in its 1H NMR spectrum, one singlet signal appears at δ = 0.67 (9H) corresponding to the three methyl groups in the tert-butyl substituent. A singlet at δ = 2.39 (3H) is assigned to the protons of the CH3-group on the phenyl

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

• conditions. High-resolution mass spectrometry (HRMS) analysis and the 1H NMR spectrum were consistent with formation of the Tb.1 complex (Figures S1 and S2 in Supporting Information File 1). Luminescence characterization of Tb.1 As anticipated, based on the previously reported europium complex ([Eu(triazole

• 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

C–C Coupling in sterically demanding porphyrin environments

• Liam Cribbin,
• Brendan Twamley,
• Nicolae Buga,
• John E. O’ Brien,
• Raphael Bühler,
• Roland A. Fischer and
• Mathias O. Senge

Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234

• compared to the 85 °C used in the synthesis of the para-equivalent 26 gave no conversion and was accompanied by the formation of palladium black [49]. No reactivity was observed by either TLC or mass spectrometry when switching back to Pd2(dba)3 with three different ligands SPhos, XantPhos, and Rac-Binap

• (Table 3, entries 7 and 8). The same success could not be replicated for OET-o-BrPPs with no reactivity being observed by TLC or by mass spectrometry. Likewise, a microwave-assisted coupling [48], resulted in no product formation (Table 3, entry 9). Thiophene-3-ylboronic acid (21) was also chosen for

• thank Dr. Gary Hessman from the Mass Spectrometry Unit in Trinity College Dublin for acquiring APCI data used in this manuscript. Funding This project has received funding from Science Foundation Ireland (SFI award 21/FFP-A/9469, PORPHYSHAPE) and was supported by the Technical University of Munich

The scent gland composition of the Mangshan pit viper, Protobothrops mangshanensis

• Jonas Holste,
• Paul Weldon,
• Donald Boyer and
• Stefan Schulz

Beilstein J. Org. Chem. 2024, 20, 2644–2654, doi:10.3762/bjoc.20.222

• , proline-containing diketopiperazines were identified for the first time in snake scent glands, although an artificial formation from amino acids likely present in the secretion cannot be excluded. Keywords: carboxylic acids; identification; mass spectrometry; pheromones; snakes; Introduction Located in

• investigated by direct inlet atmospheric solids analysis probe-atmospheric mass spectrometry (ASAP-APCI-MS), which allows the detection of secondary metabolites up to a molecular mass of 1,500 Da, but no additional compounds were detected. A more detailed description of the use of this method in natural

• column (30 m × 0.25 mm, 0.25 µm film thickness) with helium as the carrier gas. The eluted compounds were applied to a ZnSe disk rotating at 4 mm/min at −40 °C. The resulting IR spectra were processed using GRAMS/AI 9.2 software (Thermo Fisher Scientific). High-resolution mass spectrometry data were

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

• formation of various unidentified byproducts. The obtained tetronic acids 4 are solid crystalline compounds, whose structure was proved by 1H, 13C NMR spectroscopy and high-resolution mass spectrometry. The 1H NMR spectra of the synthesized products contain characteristic signals of protons of the methyl

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

• desorption ionization time-of-flight mass spectrometry (MALDI–TOF MS). The synthesized ion pairs showed similar electronic properties in solution state. In CH3CN, 2+-BF4− exhibited UV–vis absorptions at 273, 350, and 524 nm and fluorescence emission at 607 nm upon excitation at 524 nm. The absorption band at

Visible-light-mediated flow protocol for Achmatowicz rearrangement

• Joachyutharayalu Oja,
• Sanjeev Kumar and
• Srihari Pabbaraja

Beilstein J. Org. Chem. 2024, 20, 2493–2499, doi:10.3762/bjoc.20.213

• corresponding products (3o, 3p) in good yields. All the products obtained were characterized by 1H NMR, 13C NMR and mass spectrometry techniques. A plausible catalytic cycle has been postulated based on a literature study [13], and is shown in Figure 2. With the exposure of photocatalyst to sunlight/LED light

Phenylseleno trifluoromethoxylation of alkenes

• Clément Delobel,
• Armen Panossian,
• Gilles Hanquet,
• Frédéric R. Leroux,
• Fabien Toulgoat and
• Thierry Billard

Beilstein J. Org. Chem. 2024, 20, 2434–2441, doi:10.3762/bjoc.20.207

• experimental and analytical data and NMR spectra. Acknowledgements The NMR Center and the Mass Spectrometry Center are acknowledged for their analysis. Funding The authors are grateful to the French National Research Agency (ANR; grant no. 20-CE07-0004-02, Ap-PET-I). The CNRS, the French Ministry of Education

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

• , indicating that the developed tandem protocol does not depend on the presence of the N-oxide moiety in the parent heterocycle. All synthesized triazinones 1 and 7 were fully characterized by IR, 1H and 13C NMR spectroscopy, and high-resolution mass spectrometry. The structure of compounds 1b and 7h was

Improved deconvolution of natural products’ protein targets using diagnostic ions from chemical proteomics linkers

• Andreas Wiest and
• Pavel Kielkowski

Beilstein J. Org. Chem. 2024, 20, 2323–2341, doi:10.3762/bjoc.20.199

• action on a molecular level. To search elusive, often labile, and low-abundant conjugates between proteins and active compounds, chemical proteomics introduces a feasible strategy that allows to enrich and detect these conjugates. Recent advances in mass spectrometry techniques and search algorithms

• identification rates and may help to identify otherwise difficult to find interactions between active compounds and proteins, which may result from unperturbed conditions, and thus are of high physiological relevance. Keywords: chemical proteomics; diagnostic ions; mass spectrometry; target identification

• disease [2][3]. In parallel, mass spectrometry (MS) has been crucial in many areas centered around the characterization of NPs [4]. First to annotate their often complex structures using diverse fragmentation techniques [4]. Nowadays, MS is applied for the identification of NPs’ cellular protein targets

Deuterated reagents in multicomponent reactions to afford deuterium-labeled products

• Kevin Schofield,
• Shayna Maddern,
• Yueteng Zhang,
• Grace E. Mastin,
• Rachel Knight,
• Wei Wang,
• James Galligan and
• Christopher Hulme

Beilstein J. Org. Chem. 2024, 20, 2270–2279, doi:10.3762/bjoc.20.195

• . Optimization of deuterated Leuckart–Wallach reactiona. Microsomal stability package of deuterated and non-deuterated dihydropyridines. Supporting Information Supporting Information File 86: Experimental and analytical data and copies of NMR spectra. Acknowledgements We thank the UA mass spectrometry and NMR

Novel truxene-based dipyrromethanes (DPMs): synthesis, spectroscopic characterization and photophysical properties

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2024, 20, 2163–2170, doi:10.3762/bjoc.20.186

• derivatives were successfully characterized and their structures were established by means of the 1H and 13C NMR spectroscopy, besides further confirmation by mass spectrometry (see Supporting Information File 1). The UV–vis absorption, emission and time-resolved fluorescence spectra Emission and absorption

A facile three-component route to powerful 5-aryldeazaalloxazine photocatalysts

• Ivana Weisheitelová,
• Radek Cibulka,
• Marek Sikorski and
• Tetiana Pavlovska

Beilstein J. Org. Chem. 2024, 20, 1831–1838, doi:10.3762/bjoc.20.161

• unexpected structure of product 6 was confirmed by 1H, 13C NMR and mass spectrometry. The main feature of the 1H NMR spectrum of compound 6 is the absence of the signals of the aromatic aldehyde moiety and the appearance of the singlet of the 5-CH methyne group at 9.56 ppm and the singlets of the protons of

• source in this reaction, a deuterium labelling experiment was conducted (Scheme 2C). Indeed, the deazaalloxazine derivative 6-d with quantitative incorporation of deuterium in C(5) position, was isolated and confirmed by 1H NMR analysis and mass spectrometry (for more details on possible reaction

Ugi bisamides based on pyrrolyl-β-chlorovinylaldehyde and their unusual transformations

• Alexander V. Tsygankov,
• Vladyslav O. Vereshchak,
• Tetiana O. Savluk,
• Serhiy M. Desenko,
• Valeriia V. Ananieva,
• Oleksandr V. Buravov,
• Yana I. Sakhno,
• Svitlana V. Shishkina and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2024, 20, 1773–1784, doi:10.3762/bjoc.20.156

• stirring for three hours (Scheme 3, conditions A). However, the results of this attempted post-Ugi transformation were quite unexpected: Instead of acid 11, we isolated the amide of the unsaturated derivative of pyruvic acid 10a according to the 1H and 13C NMR spectra and mass spectrometry data. In order

• conventional thermal heating, amide 10a was isolated, albeit in a lower yield and accompanied with tar formation. In addition to the 1H, 13C NMR spectra and mass spectrometry data, the structure of compound 10d was established by X-ray diffraction analysis (Figure 3). It was also found that the substituents at

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

• detected as a side reaction via mass spectrometry. Vinyl alcohols were also studied, giving carvone (4v) in 74% yield without oxidation of the double bonds. Finally, other heterocyclic benzylic alcohols were investigated, which led to undesired chlorinations in the case of benzimidazoles 3w and 3x and

New triazinephosphonate dopants for Nafion proton exchange membranes (PEM)

• Fátima C. Teixeira,
• António P. S. Teixeira and
• C. M. Rangel

Beilstein J. Org. Chem. 2024, 20, 1623–1634, doi:10.3762/bjoc.20.145

• characterization of the dopants was carried out by Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). 1H, 13C and 31P NMR characterization was done using different one- and two-dimensional techniques, and were obtained on a Bruker Avance III HD