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

• Fisatom Model 431 apparatus. Hydrogen and carbon nuclear magnetic resonance spectra (NMR), homonuclear 1H,1H (COSY and NOESY) and heteronuclear 1H,13C (HSQC, HMBC) experiments were recorded on a 400 MHz Avance III (Bruker, Billerica, MA) spectrometer. Samples were dissolved in 0.5 mL DMSO-d6 and spectra

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

• Jessica Villegas,
• Bryce C. Ball,
• Katelyn M. Shouse,
• Caleb W. VanArragon,
• Ashley N. Wasserman,
• Hannah E. Bhakta,
• Allen G. Oliver,
• Danielle A. Orozco-Nunnelly and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

• cells [9]. The quantification of c-MYC (oncogene) and APC (tumor suppressor) mRNA levels helped begin to elucidate how the A. mexicana root methanol extract may be affecting colon cancer cells. After chromatographic separations, UPLC–MS, and subsequent nuclear magnetic resonance analysis of the root and

Intermediates and shunt products of massiliachelin biosynthesis in Massilia sp. NR 4-1

• Till Steinmetz,
• Blaise Kimbadi Lombe and
• Markus Nett

Beilstein J. Org. Chem. 2023, 19, 909–917, doi:10.3762/bjoc.19.69

• -chelating molecules. After a thorough inspection of its metabolic profile, six previously overlooked compounds were isolated that were active in the chrome azurol S (CAS) assay. Mass spectrometric measurements and nuclear magnetic resonance spectroscopic analyses identified these compounds as possible

Non-peptide compounds from Kronopolites svenhedini (Verhoeff) and their antitumor and iNOS inhibitory activities

• Yuan-Nan Yuan,
• Jin-Qiang Li,
• Hong-Bin Fang,
• Shao-Jun Xing,
• Yong-Ming Yan and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 789–799, doi:10.3762/bjoc.19.59

• , accompanied by two known flavan derivatives 5 and 6 and a known olefine acid (9) were isolated from whole bodies of Kronopolites svenhedini (Verhoeff). The structures of the new compounds were determined by 1D and 2D nuclear magnetic resonance (NMR) and other spectroscopic methods, as well as computational

Bromination of endo-7-norbornene derivatives revisited: failure of a computational NMR method in elucidating the configuration of an organic structure

• Demet Demirci Gültekin,
• Arif Daştan,
• Yavuz Taşkesenligil,
• Cavit Kazaz,
• Yunus Zorlu and
• Metin Balci

Beilstein J. Org. Chem. 2023, 19, 764–770, doi:10.3762/bjoc.19.56

• erroneous mechanistic pathway. Keywords: bromination; computational NMR; γ-gauche effect; NMR; NOE-Diff experiments; Introduction Nuclear magnetic resonance (NMR) spectroscopy is one of the most important analytical tools used to determine the structure of organic compounds. NMR not only confirms the

• configuration in a molecule, in short, it is the single most important spectroscopic tool aside from X-ray crystallography to provide an accurate ensemble-guided view of the structure, even conformational dynamics in a molecule. Quantum mechanical/nuclear magnetic resonance (NMR) approaches are used for the

Direct C2–H alkylation of indoles driven by the photochemical activity of halogen-bonded complexes

• Martina Mamone,
• Giuseppe Gentile,
• Jacopo Dosso,
• Maurizio Prato and
• Giacomo Filippini

Beilstein J. Org. Chem. 2023, 19, 575–581, doi:10.3762/bjoc.19.42

• both UV–vis and nuclear magnetic resonance (NMR) spectroscopy [29]. In particular, the optical absorption spectra of substrate 2a (green dotted line), DABCO (red dotted line), and the solution containing both 2a and DABCO (blue line) were recorded in acetonitrile (Figure 2). Specifically, it was

Discrimination of β-cyclodextrin/hazelnut (Corylus avellana L.) oil/flavonoid glycoside and flavonolignan ternary complexes by Fourier-transform infrared spectroscopy coupled with principal component analysis

• Nicoleta G. Hădărugă,
• Gabriela Popescu,
• Dina Gligor (Pane),
• Cristina L. Mitroi,
• Sorin M. Stanciu and
• Daniel Ioan Hădărugă

Beilstein J. Org. Chem. 2023, 19, 380–398, doi:10.3762/bjoc.19.30

• complexes and flavonoids were very well classified and discriminated by FTIR–PCA, especially through the type of antioxidant used. However, further synthesis methods and analyses (slow co-crystallization, single-crystal X-ray diffraction, 1H and 13C nuclear magnetic resonance analyses) are needed for the

Investigation of cationic ring-opening polymerization of 2-oxazolines in the “green” solvent dihydrolevoglucosenone

• Solomiia Borova and
• Robert Luxenhofer

Beilstein J. Org. Chem. 2023, 19, 217–230, doi:10.3762/bjoc.19.21

• polymerization process. Further work will be necessary to establish whether a living polymerization can be achieved by additional adjustments. Keywords: 2-alkyl-2-oxazolines; matrix-assisted laser desorption/ionization mass spectrometry; nuclear magnetic resonance; polymerization kinetics; Introduction

Solid-phase total synthesis and structural confirmation of antimicrobial longicatenamide A

• Takumi Matsumoto,
• Takefumi Kuranaga,
• Yuto Taniguchi,
• Weicheng Wang and
• Hideaki Kakeya

Beilstein J. Org. Chem. 2022, 18, 1560–1566, doi:10.3762/bjoc.18.166

• . pulmonis TP-B0596 [8]. The planar structures were determined by analyzing two-dimensional (2D) nuclear magnetic resonance (NMR) spectra and mass spectrometry (MS) data, and the absolute configurations of their component amino acids were elucidated by using highly sensitive reagents that we recently

Mechanochemical bottom-up synthesis of phosphorus-linked, heptazine-based carbon nitrides using sodium phosphide

• Blaine G. Fiss,
• Georgia Douglas,
• Michael Ferguson,
• Jorge Becerra,
• Jesus Valdez,
• Trong-On Do,
• Tomislav Friščić and
• Audrey Moores

Beilstein J. Org. Chem. 2022, 18, 1203–1209, doi:10.3762/bjoc.18.125

• , mechanochemical synthesis of phosphorus-bridged heptazine-based carbon nitrides (g-h-PCN). The structure of these materials was determined through a combination of powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), 31P magic angle spinning nuclear magnetic resonance (MAS NMR), density

Cholyl 1,3,4-oxadiazole hybrid compounds: design, synthesis and antimicrobial assessment

• Anas J. Rasras,
• Mohamed El-Naggar,
• Nesreen A. Safwat and
• Raed A. Al-Qawasmeh

Beilstein J. Org. Chem. 2022, 18, 631–638, doi:10.3762/bjoc.18.63

• were obtained from piperidine and pyrrolidine, respectively, as secondary cyclic amine component (Figure 2). The structures of the newly synthesized compounds were confirmed on the basis of their spectral data in particular nuclear magnetic resonance (NMR) and mass spectrometry (MS) techniques. The 1H

Sesquiterpenes from the soil-derived fungus Trichoderma citrinoviride PSU-SPSF346

• Wiriya Yaosanit,
• Vatcharin Rukachaisirikul,
• Souwalak Phongpaichit,
• Sita Preedanon and
• Jariya Sakayaroj

Beilstein J. Org. Chem. 2022, 18, 479–485, doi:10.3762/bjoc.18.50

• using a Shimadzu UV-2600 UV–vis spectrophotometer in MeOH. ECD spectra were recorded on a JASCO J-815 polarimeter. 1H and 13C nuclear magnetic resonance (1H and 13C NMR) spectra were recorded on 300 and 500 MHz Bruker FTNMR Ultra ShieldTM spectrometers. Specific rotations were measured with a JASCO P

Synthesis of 3,4,5-trisubstituted isoxazoles in water via a [3 + 2]-cycloaddition of nitrile oxides and 1,3-diketones, β-ketoesters, or β-ketoamides

• Md Imran Hossain,
• Md Imdadul H. Khan,
• Seong Jong Kim and
• Hoang V. Le

Beilstein J. Org. Chem. 2022, 18, 446–458, doi:10.3762/bjoc.18.47

• polarity on the keto–enol equilibrium of the 1,3-diketones, which influences the results of the [3 + 2] cycloaddition reactions under mild basic conditions, via nuclear magnetic resonance (NMR) spectroscopy. The 1H NMR spectra of 1-phenyl-1,3-butanedione (2a) in CDCl3 and in methanol-d4 indicated that the

Synthesis of piperidine and pyrrolidine derivatives by electroreductive cyclization of imine with terminal dihaloalkanes in a flow microreactor

• Yuki Naito,
• Naoki Shida and
• Mahito Atobe

Beilstein J. Org. Chem. 2022, 18, 350–359, doi:10.3762/bjoc.18.39

• nuclear magnetic resonance (NMR) spectra were recorded on a spectrometer (DRX-500, Bruker; 500 MHz) using tetramethylsilane (TMS) as an internal standard with the solvent resonance (CDCl3: δ 7.26). The chemical shifts for 1H NMR spectra are given in δ (ppm) relative to the TMS internal standard

1,2-Naphthoquinone-4-sulfonic acid salts in organic synthesis

• Ruan Carlos B. Ribeiro,
• Patricia G. Ferreira,
• Amanda de A. Borges,
• Luana da S. M. Forezi,
• Fernando de Carvalho da Silva and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 53–69, doi:10.3762/bjoc.18.5

• phenethylamine derivatives (amphetamine, methamphetamine, 2,5-dimethoxy-4-methylamphetamine, mescaline, ephedrine, and norephedrine). The reaction products were separated by thin-layer chromatography and analyzed by elemental analysis, nuclear magnetic resonance, infrared spectroscopy, and mass spectrometry. In

Biological properties and conformational studies of amphiphilic Pd(II) and Ni(II) complexes bearing functionalized aroylaminocarbo-N-thioylpyrrolinate units

• Samet Poyraz,
• Samet Belveren,
• Sabriye Aydınoğlu,
• Mahmut Ulger,
• Abel de Cózar,
• Maria de Gracia Retamosa,
• Jose M. Sansano and
• H. Ali Döndaş

Beilstein J. Org. Chem. 2021, 17, 2812–2821, doi:10.3762/bjoc.17.192

• the IR spectra (recorded using a Nicolet 510 P-FT) are listed and wave numbers are given in cm−1. Nuclear magnetic resonance spectra and decoupling experiments were determined at 250 MHz on a Q.E 300 instrument, at 300 MHz on a Bruker Avance AC-300 and at 500 MHz on a Bruker AM500 spectrometer as

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

• stated. The dialysis tubings were purchased from Spectrum Labs (Spectra/PorTM, pre-wetted tubing, 3.5 kDa) and were rinsed with water before use. Nuclear magnetic resonance spectra were measured using a Bruker AC 300 (300 MHz) spectrometer at 298 K (Billerica, MA, USA). The chemical shift is given in

Constrained thermoresponsive polymers – new insights into fundamentals and applications

• Patricia Flemming,
• Alexander S. Münch,
• Andreas Fery and
• Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

A new and efficient methodology for olefin epoxidation catalyzed by supported cobalt nanoparticles

• Lucía Rossi-Fernández,
• Viviana Dorn and
• Gabriel Radivoy

Beilstein J. Org. Chem. 2021, 17, 519–526, doi:10.3762/bjoc.17.46

• , 240–400 mesh). Thin-layer chromatography (TLC) was performed on precoated silica gel plates (Merck 60, F254, 0.25 mm). Instrumentation and analysis Nuclear magnetic resonance (NMR) spectra were recorded on a Bruker ARX-300 spectrophotometer using CDCl3 as the solvent and tetramethylsilane (TMS) as

¹⁹F NMR as a tool in chemical biology

• Diana Gimenez,
• Aoife Phelan,
• Cormac D. Murphy and
• Steven L. Cobb

Beilstein J. Org. Chem. 2021, 17, 293–318, doi:10.3762/bjoc.17.28

• ]. Furthermore, owing to the lack of naturally-occurring fluorinated compounds, fluorine is a useful probe to investigate structure and mechanism of biological molecules. Central to these studies is fluorine-19 nuclear magnetic resonance spectroscopy (19F NMR), which allows the user to readily visualize changes

Molecular basis for protein–protein interactions

• Brandon Charles Seychell and
• Tobias Beck

Beilstein J. Org. Chem. 2021, 17, 1–10, doi:10.3762/bjoc.17.1

• methods. These methods are summarised in Figure 1. Atomic resolution methods focus on the structure determination of protein complexes and elucidating the PPIs at a near-atomic resolution. Such methods include X-ray crystallography [12], nuclear magnetic resonance (NMR) [13], and cryogenic electron

Naphthalonitriles featuring efficient emission in solution and in the solid state

• Sidharth Thulaseedharan Nair Sailaja,
• Iván Maisuls,
• Jutta Kösters,
• Alexander Hepp,
• Andreas Faust,
• Jens Voskuhl and
• Cristian A. Strassert

Beilstein J. Org. Chem. 2020, 16, 2960–2970, doi:10.3762/bjoc.16.246

• characterized by nuclear magnetic resonance spectroscopy (NMR, Supporting Information File 1, Figures S1–S24) as well as exact electrospray mass spectrometry (EM–ESIMS, Supporting Information File 1, Figures S25–S30) and appear as white to faint yellow solids. Only the dimethylamino-substituted product shows a

Leveraging glycomics data in glycoprotein 3D structure validation with Privateer

• Haroldas Bagdonas,
• Daniel Ungar and
• Jon Agirre

Beilstein J. Org. Chem. 2020, 16, 2523–2533, doi:10.3762/bjoc.16.204

• glycoproteins Several experimental techniques can be used to obtain 3D structures of glycoproteins: X-ray crystallography (MX, which stands for macromolecular crystallography), nuclear magnetic resonance spectroscopy (NMR) and electron cryomicroscopy (cryo-EM). As of publication date, the overwhelming majority

• and the chain length. However, the in-depth analysis of a glycan typically requires the integration of complementary analytic techniques, such as nuclear magnetic resonance (NMR) and capillary electrophoresis (CE). Nevertheless, depending on the sample, advanced mass spectrometry techniques can be

Computational tools for drawing, building and displaying carbohydrates: a visual guide

• Kanhaya Lal,
• Rafael Bermeo and
• Serge Perez

Beilstein J. Org. Chem. 2020, 16, 2448–2468, doi:10.3762/bjoc.16.199

• areas of chemical and biochemical fragmentations followed by analysis using mass spectroscopy, nuclear magnetic resonance, crystallography and computational modelling. There have been some initiatives by independent research groups worldwide, that pushed the development of visual tools to improve some

Development of fluorinated benzils and bisbenzils as room-temperature phosphorescent molecules

• Shigeyuki Yamada,
• Takuya Higashida,
• Yizhou Wang,
• Masato Morita,
• Takuya Hosokai,
• Kaveendra Maduwantha,
• Kaveenga Rasika Koswattage and
• Tsutomu Konno

Beilstein J. Org. Chem. 2020, 16, 1154–1162, doi:10.3762/bjoc.16.102

• . Interestingly, stirring 1a in DMSO solution in the presence of 30 mol % of PdCl2 at 140 °C for 17 h produced two products (56% yield for the more polar product and 37% yield for the less polar product) after purification with column chromatography. Spectroscopic analyses (i.e., 1H, 19F, and 13C nuclear magnetic

• resonance (NMR) spectroscopy, infrared spectroscopy, and high-resolution mass spectrometry) successfully identified the more polar product as the half-oxidized benzil 2a and the less polar one as the fully oxidized bisbenzil 3a. Fluorinated bistolane 1b, bearing a hexyloxy chain, also underwent PdCl2