Formaldehyde surrogates in multicomponent reactions

• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Bernhard Westermann

Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45

• for the formation of intermediates. Gao et al. studied the generation of metal acetylide A by IR spectroscopy [65]. When subsequent additions of 1 equiv FeCl3 were made in a solution of alkyne and TMG, the C–H stretch peak at 3277 cm−1 started to decrease as the temperature increased from 30 to 100 °C

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

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

• the Institute for Solid State Physics, the University of Tokyo (1H, 13C, and 19F NMR spectrometer, mass spectroscopy system, and IR spectroscopy system in Mori Laboratory). Funding This work was financially supported by JSPS KAKENHI Grant Number JP21K05066 in Grant-in-Aid for Scientific Research (C

A new analog of dihydroxybenzoic acid from Saccharopolyspora sp. KR21-0001

• Rattiya Janthanom,
• Yuta Kikuchi,
• Hiroki Kanto,
• Tomoyasu Hirose,
• Arisu Tahara,
• Takahiro Ishii,
• Arinthip Thamchaipenet and
• Yuki Inahashi

Beilstein J. Org. Chem. 2024, 20, 497–503, doi:10.3762/bjoc.20.44

• ppm) in the 13C NMR spectra. Infrared (IR) spectroscopy was carried out using an FT-4600 Fourier transform infrared spectrometer (JASCO P-2200 Polarimeter, Japan). The UV spectra were measured using a SpectraMax QuickDrop micro-volume spectrophotometer (Molecular Devices, LLC., San Jose, USA) at

Facile approach to N,O,S-heteropentacycles via condensation of sterically crowded 3H-phenoxazin-3-one with ortho-substituted anilines

• Eugeny Ivakhnenko,
• Vasily Malay,
• Pavel Knyazev,
• Nikita Merezhko,
• Nadezhda Makarova,
• Oleg Demidov,
• Gennady Borodkin,
• Andrey Starikov and
• Vladimir Minkin

Beilstein J. Org. Chem. 2024, 20, 336–345, doi:10.3762/bjoc.20.34

• short-term heating of the melted reactants at 220–250 °C is described, and the compounds were characterized by means of single-crystal X-ray crystallography, NMR, UV–vis, and IR spectroscopy, as well as cyclic voltammetry. The reaction with o-amino-, o-hydroxy-, and o-mercapto-substituted arylamines

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

• observed for C2 when replacing its acidic proton with a CS2 group among all the nucleophilic carbene precursors that we have investigated so far [40][75]. Yet, we do not have an explanation for it. On IR spectroscopy, the most intense absorption in the ATR spectra of compounds 4a–c and 6a–f was always due

• lower energies is a likely consequence of the greater donicity of CAACs and MICs vs NHCs. Hence, the ν̃ CS2 values recorded on IR spectroscopy constitute a more sensitive probe than the δ CS2 values obtained from 13C NMR spectroscopy to help discriminate the various types of dithiocarboxylate adducts

GlAIcomics: a deep neural network classifier for spectroscopy-augmented mass spectrometric glycans data

• Thomas Barillot,
• Baptiste Schindler,
• Baptiste Moge,
• Elisa Fadda,
• Franck Lépine and
• Isabelle Compagnon

Beilstein J. Org. Chem. 2023, 19, 1825–1831, doi:10.3762/bjoc.19.134

• intelligence in combination with spectroscopy-augmented mass spectrometry for carbohydrates sequencing and glycomics applications. Keywords: Bayesian neural network; deep learning; glycomics; IR; spectroscopy; Introduction DNA and protein sequencing technologies that aim at determining the structure of a

• each monosaccharide unit is measured, and subsequently identified by comparison with a library of reference spectra of synthetic monosaccharide standards. In the early days of MS–IR spectroscopy, ca. one hour was necessary to record the IR fingerprint of a single molecule and the identification was

• approach is based on the IRMPD spectroscopic scheme (infrared multiple photon dissociation), which is the combination of mass spectrometry and IR spectroscopy. IRMPD is an action spectroscopy method that allows recording IR absorption spectra of isolated gas-phase ions, based on the measurement of the

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

• associated with this absorption centered at 615 nm possess a low molar extinction coefficient (ε ≈ 220 cm−1 M−1, inset in Figure 3). Infrared (IR) spectroscopy was performed via attenuated total reflectance (ATR) and showed the characteristic stretching vibration of the NCS groups at 2069 cm−1 (Figure S3 in

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• maintained in DMSO-d6 solution. It is worth noting that the presence of the electron-withdrawing nitro substituent in hdz-NO2 makes the interaction stronger. An IR spectroscopy study, which was supported by computational calculations, as well as a complete NMR characterization of both compounds, align with

CO₂ complexation with cyclodextrins

• Cecilie Høgfeldt Jessen,
• Jesper Bendix,
• Theis Brock Nannestad,
• Heloisa Bordallo,
• Martin Jæger Pedersen,
• Christian Marcus Pedersen and
• Mikael Bols

Beilstein J. Org. Chem. 2023, 19, 1021–1027, doi:10.3762/bjoc.19.78

• get more information about the CO2 content in the crystal samples we also analyzed the crystals by thermogravimetric analysis. The crystal samples where heated to 26–200 °C at different rates and weight loss observed while the gas release was monitored by IR spectroscopy. Two distinguished weight

Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis

• Prodip Howlader and
• Michael Schmittel

Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62

• of the guest molecule was proven by UV–vis and IR spectroscopy. The multicomponent prism (Figure 3) was finally utilized as a heterogeneous catalyst for Michael and Diels–Alder (DA) reactions in water, representing an uncommon hydrogen-bond donating heterogeneous catalyst [59]. Intrigued by the

Comparative study of thermally activated delayed fluorescent properties of donor–acceptor and donor–acceptor–donor architectures based on phenoxazine and dibenzo[a,j]phenazine

• Saika Izumi,
• Prasannamani Govindharaj,
• Anna Drewniak,
• Paola Zimmermann Crocomo,
• Satoshi Minakata,
• Leonardo Evaristo de Sousa,
• Piotr de Silva,
• Przemyslaw Data and
• Youhei Takeda

Beilstein J. Org. Chem. 2022, 18, 459–468, doi:10.3762/bjoc.18.48

• compound 1 was fully characterized by 1H and 13C NMR and IR spectroscopy, MS spectrometry as well as elemental analysis (for the detailed data, see Supporting Information File 1). Steady-state PL spectra To reveal the photophysical properties of diluted solutions of compound 1, UV–vis absorption and steady

Multi-faceted reactivity of N-fluorobenzenesulfonimide (NFSI) under mechanochemical conditions: fluorination, fluorodemethylation, sulfonylation, and amidation reactions

• José G. Hernández,
• Karen J. Ardila-Fierro,
• Dajana Barišić and
• Hervé Geneste

Beilstein J. Org. Chem. 2022, 18, 182–189, doi:10.3762/bjoc.18.20

• of solvent. Being a crystalline material [43] and a Raman and IR active molecule [44][45], NFSI enabled the monitoring of the reactions by ex situ PXRD and IR spectroscopy, as well as by in situ Raman spectroscopy. Such a monitoring enabled us to understand background reactions such as the

Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode

• Ettore Crovini,
• Zhen Zhang,
• Yu Kusakabe,
• Yongxia Ren,
• Yoshimasa Wada,
• Bilal A. Naqvi,
• Prakhar Sahay,
• Tomas Matulaitis,
• Stefan Diesing,
• Ifor D. W. Samuel,
• Wolfgang Brütting,
• Katsuaki Suzuki,
• Hironori Kaji,
• Stefan Bräse and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2021, 17, 2894–2905, doi:10.3762/bjoc.17.197

• DICzTRZ were determined by a combination of NMR spectroscopy, mass spectrometry, and IR spectroscopy. Theoretical calculations Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations in the gas phase at the PBE0/6-31G(d,p) level reveal the potential of DICzTRZ as a TADF material. The

Host–guest interaction and properties of cucurbit[8]uril with chloramphenicol

• Lin Zhang,
• Jun Zheng,
• Guangyan Luo,
• Xiaoyue Li,
• Yunqian Zhang,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2021, 17, 2832–2839, doi:10.3762/bjoc.17.194

• (CPE) was investigated using single-crystal X-ray diffraction spectroscopy, isothermal titration calorimetry (ITC) and UV–vis, NMR and IR spectroscopy. The effects of Q[8] on the stability, in vitro release performance and antibacterial activity of CPE were also studied. The results showed that CPE and

• consistent with our single-crystal X-ray analysis of CPE@Q[8] shown in Figure 2. IR spectroscopy Figure 6 shows the IR spectra recorded for Q[8] (a), CPE (b), a physical mixture of Q[8] and CPE {n(Q[8])/n(CPE) = 1:1} (c) and the CPE@Q[8] inclusion complex (d). By comparison, spectrum (c) is a simple

• . Conclusion Herein, the 1:1 host–guest complex of CPE and Q[8] was confirmed using single-crystal X-ray diffraction and 1H NMR, UV–vis and IR spectroscopy. The CPE molecule completely enters the cavity of Q[8] with an inclusion constant of 5.474 × 105 L/mol. The intervention of Q[8] has no effect on the

In-depth characterization of self-healing polymers based on π–π interactions

• Josefine Meurer,
• Julian Hniopek,
• Johannes Ahner,
• Michael Schmitt,
• Jürgen Popp,
• Stefan Zechel,
• Kalina Peneva and
• Martin D. Hager

Beilstein J. Org. Chem. 2021, 17, 2496–2504, doi:10.3762/bjoc.17.166

• mechanical behavior was studied using rheology. The activation of the supramolecular interactions results in a breaking of these noncovalent bonds, which was investigated using IR spectroscopy, leading to a sufficient increase in mobility and, finally, a healing of the mechanical damage. This scratch-healing

• were synthesized and characterized in detail. The mechanical and thermal behavior was studied revealing an activation of the supramolecular interactions at 125 °C. This finding could also be verified by temperature-depending IR-spectroscopy indicating a broadening of the aromatic signals at 150 °C

• supramolecular bonds like ionic interactions [27]. In this temperature range, G'' is higher than G' showing that the polymer is uncrosslinked. Thus, the mobility is very high, which is a precondition for the healing. To get further insight into the molecular behavior of P1 and P2, temperature dependent IR

Design, synthesis and photophysical properties of novel star-shaped truxene-based heterocycles utilizing ring-closing metathesis, Clauson–Kaas, Van Leusen and Ullmann-type reactions as key tools

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2021, 17, 1374–1384, doi:10.3762/bjoc.17.96

• mixture of EtOAc and petroleum ether. Characterization of the intermediates and final compounds were performed using 1H and 13C NMR, mass spectrometry and IR spectroscopy. FTIR spectra of the compounds were recorded on an Aligent FTIR spectrometer (ATR module of Cary 630 FTIR, Agilent Technologies) from

Icilio Guareschi and his amazing “1897 reaction”

• Gian Cesare Tron,
• Alberto Minassi,
• Giovanni Sorba,
• Mara Fausone and
• Giovanni Appendino

Beilstein J. Org. Chem. 2021, 17, 1335–1351, doi:10.3762/bjoc.17.93

• critical for the identification of functional groups, being the equivalent of what next became IR spectroscopy. Schiff himself had contributed to this development with the discovery of the sulfite-decolorized fuchsine test for aldehydes and with the popularization of the biuret test for peptide bonds. It

CF₃-substituted carbocations: underexploited intermediates with great potential in modern synthetic chemistry

• Anthony J. Fernandes,
• Armen Panossian,
• Bastien Michelet,
• Agnès Martin-Mingot,
• Frédéric R. Leroux and
• Sébastien Thibaudeau

Beilstein J. Org. Chem. 2021, 17, 343–378, doi:10.3762/bjoc.17.32

• secondary derivatives 112a–c and 113a,b afforded oils. The secondary derivatives were much more sensitive in spite of the use of electron-rich Co–Mo clusters and could only be characterized by NMR and IR spectroscopy [85]. Upon ionization, the change in the electronic density is directly reflected by the

UV resonance Raman spectroscopy of the supramolecular ligand guanidiniocarbonyl indole (GCI) with 244 nm laser excitation

• Tim Holtum,
• Vikas Kumar,
• Daniel Sebena,
• Jens Voskuhl and
• Sebastian Schlücker

Beilstein J. Org. Chem. 2020, 16, 2911–2919, doi:10.3762/bjoc.16.240

• vibrational modes of the molecule. Especially for non-covalent interactions such as hydrogen bonding, vibrational spectroscopy has been shown to be very sensitive [10][11]. In the context of supramolecular recognition, for example, IR spectroscopy has been applied to monitor the binding of tetrapeptides by

• GCP-based supramolecular ligands containing also a tripeptide part for increasing selectivity [12]. However, IR spectroscopy does not provide selectivity for probing only the CBS. This is not critical as long as the binding partner is a small peptide, i.e., when the spectrum is not too crowded because

• of the small number of vibrational peaks. Additionally, IR spectroscopy suffers from the strong absorption by water. In contrast, this is not a problem in Raman spectroscopy because water is a weak Raman scatterer. Conventional Raman spectroscopy under nonresonant conditions is typically limited to

One-pot multicomponent green Hantzsch synthesis of 1,2-dihydropyridine derivatives with antiproliferative activity

• Giovanna Bosica,
• Kaylie Demanuele,
• José M. Padrón and
• Adrián Puerta

Beilstein J. Org. Chem. 2020, 16, 2862–2869, doi:10.3762/bjoc.16.235

• general structure, corresponding to the 1,2-DHP regioisomer, unless when using aliphatic aldehydes. Experimental General All the chemicals used were purchased form Sigma-Aldrich. IR spectroscopy studies were conducted on a Shimadzu IRAffinity-1 FTIR spectrometer calibrated against 1602 cm−1 polystyrene

Host–guest interaction of cucurbit[8]uril with oroxin A and its effect on the properties of oroxin A

• Zhishu Zeng,
• Jun Xie,
• Guangyan Luo,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2020, 16, 2332–2337, doi:10.3762/bjoc.16.194

• –guest interactions between oroxin A (OA) and cucurbit[8]uril (Q[8]) using 1H NMR, MS, UV–vis and IR spectroscopy. The results showed that OA and Q[8] formed an inclusion compound (OA@Q[8]) with a molar ratio of 1:1 and a binding constant of 1.299 × 107 L·mol−1. In addition, the effect of Q[8] on the

Access to highly substituted oxazoles by the reaction of α-azidochalcone with potassium thiocyanate

• Mysore Bhyrappa Harisha,
• Pandi Dhanalakshmi,
• Rajendran Suresh,
• Raju Ranjith Kumar and
• Shanmugam Muthusubramanian

Beilstein J. Org. Chem. 2020, 16, 2108–2118, doi:10.3762/bjoc.16.178

• ). All the synthesized compounds 4a–l were confirmed by 1D and 2D NMR, IR spectroscopy and HRMS techniques. Additional evidence of the structures of these compounds was obtained based on the single-crystal X-ray analysis of 4h [71] (Figure 4). The nitrogen end of the thiocyanate attacks the azirine to

Natural dolomitic limestone-catalyzed synthesis of benzimidazoles, dihydropyrimidinones, and highly substituted pyridines under ultrasound irradiation

• Kumar Godugu,
• Venkata Divya Sri Yadala,
• Mohammad Khaja Mohinuddin Pinjari,
• Trivikram Reddy Gundala,
• Lakshmi Reddy Sanapareddy and
• Chinna Gangi Reddy Nallagondu

Beilstein J. Org. Chem. 2020, 16, 1881–1900, doi:10.3762/bjoc.16.156

• bending vibrations of water [82]. The impurities aluminium silicate and iron oxides in the NDL were confirmed by IR spectroscopy. The peaks located at 446, 551, 817, 952, 1247, and 1383 cm−1 were attributed to the Si–O bending, Fe–O stretching, Al–O–Si stretching, Si–OH bending, Si–O stretching, and Al–O

One-step route to tricyclic fused 1,2,3,4-tetrahydroisoquinoline systems via the Castagnoli–Cushman protocol

• Aleksandar Pashev,
• Nikola Burdzhiev and
• Elena Stanoeva

Beilstein J. Org. Chem. 2020, 16, 1456–1464, doi:10.3762/bjoc.16.121

• . The structure of 27 was proven by a combination of 1D and 2D NMR spectra, and IR spectroscopy. The reactivity of thiodiacetic anhydride 8 towards the imines 19 and 20 was different to that of the anhydrides 5–7. The targeted 11b-methyl and 11b-ethyl-4-oxo-2-thiabenzo[a]quinolizidinones 28 and 29