2,4-Bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridines: synthesis and photophysical properties

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli,
• Noureddine Chaaben,
• Kamel Alimi,
• Stefan Jopp and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 1629–1640, doi:10.3762/bjoc.17.115

• group. Consequently, they influence the electronic situation of the prepared tetrahydroacridines and are expected to change their structural proprieties. Hence, some structural parameters including gap (Eg), ionization potential (IP), electron affinity (EA) and dipole moments (µ) were deduced on the

• polarity difference. In fact, derivative 4f shows the highest dipole moment of 4.276 D as compared to 4a (0.698 D). As shown in Table 5, the ionization potential (IP) and electron affinity (EA) of tetrahydroacridines are almost identical. In addition, EHOMO and ELUMO do not change notably and the

Synthesis of 1-indolyl-3,5,8-substituted γ-carbolines: one-pot solvent-free protocol and biological evaluation

• Premansh Dudhe,
• Mena Asha Krishnan,
• Kratika Yadav,
• Diptendu Roy,
• Krishnan Venkatasubbaiah,
• Biswarup Pathak and
• Venkatesh Chelvam

Beilstein J. Org. Chem. 2021, 17, 1453–1463, doi:10.3762/bjoc.17.101

• -Performance LC-MS (electrospray ionization quadrupole time-of-flight) spectrometer. X-ray structure analysis was carried out at a Bruker KAPPA APEXII single crystal X-ray diffractometer. Melting points (mp) are uncorrected and were measured on a Veego melting point apparatus (capillary method). Analytical

Structural effects of meso-halogenation on porphyrins

• Keith J. Flanagan,
• Maximilian Paradiz Dominguez,
• Zoi Melissari,
• Hans-Georg Eckhardt,
• René M. Williams,
• Dáire Gibbons,
• Caroline Prior,
• Gemma M. Locke,
• Alina Meindl,
• Aoife A. Ryan and
• Mathias O. Senge

Beilstein J. Org. Chem. 2021, 17, 1149–1170, doi:10.3762/bjoc.17.88

• quadrupole time-of-flight (Q-TOF) mass spectrometer equipped with Z-spray electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI) sources either in a positive or negative mode with DCTB (trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malononitrile) as the matrix. UV

Chiral isothiourea-catalyzed kinetic resolution of 4-hydroxy[2.2]paracyclophane

• David Weinzierl and
• Mario Waser

Beilstein J. Org. Chem. 2021, 17, 800–804, doi:10.3762/bjoc.17.68

• -resolution mass spectra were obtained using a Thermo Fisher Scientific LTQ Orbitrap XL with an Ion Max API Source. Analyses were made in the positive ionization mode if not otherwise stated. HPLC was performed using a Thermo Scientific Dionex Ultimate 3000 system with diode array detector with a CHIRAL ART

DNA with zwitterionic and negatively charged phosphate modifications: Formation of DNA triplexes, duplexes and cell uptake studies

• Yongdong Su,
• Maitsetseg Bayarjargal,
• Tracy K. Hale and
• Vyacheslav V. Filichev

Beilstein J. Org. Chem. 2021, 17, 749–761, doi:10.3762/bjoc.17.65

• was confirmed by electrospray ionization mass spectrometry (ESIMS) in the negative mode (Table 1). For clarity, we introduced the following nomenclature of the ONs synthesised. The prefix 5ʼ- or 3ʼ- with either N+ or Ts- means that the first phosphate at the 5ʼ- or 3ʼ-end was modified; m-N+ or m-Ts

Designed whole-cell-catalysis-assisted synthesis of 9,11-secosterols

• Marek Kõllo,
• Marje Kasari,
• Villu Kasari,
• Tõnis Pehk,
• Ivar Järving,
• Margus Lopp,
• Arvi Jõers and
• Tõnis Kanger

Beilstein J. Org. Chem. 2021, 17, 581–588, doi:10.3762/bjoc.17.52

• 6540 UHD Accurate-Mass QTOF LC/MS spectrometer by using AJ-ESI as an ionization method. Construction of biocatalyst Plasmid cloning and amplification were performed in E. coli DH5 strain. E. coli strain BL21 (DE3) was used for biocatalysis experiments. Lysogeny broth (LB) medium was used for all cell

Helicene synthesis by Brønsted acid-catalyzed cycloaromatization in HFIP [(CF₃)₂CHOH]

• Takeshi Fujita,
• Noriaki Shoji,
• Nao Yoshikawa and
• Junji Ichikawa

Beilstein J. Org. Chem. 2021, 17, 396–403, doi:10.3762/bjoc.17.35

• metal catalysts. Recently, we have developed a Brønsted acid-catalyzed cycloaromatization in 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP) as solvent [20][21][22]. Fluoroalcohols, such as HFIP, exhibit high ionization power and low nucleophilicity, based on the electron-withdrawing inductive effect of

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

• environment will be scrutinized. The chapter will summarize kinetic studies and concomitant theoretical investigations on the cations formation and stability data as well as synthetic perspectives offered by the studied carbenium ions. Any discussion of the results coming from the ionization of perfluorinated

• spectroscopic evidence for the complete ionization of several α-(trifluoromethyl) alcohol precursors 9a–c in a superacidic FSO3H–SbF5–SO2 medium. They also brought experimental 19F NMR variation values up to Δδ = +24.8 ppm (Scheme 3). This suggests a partial stabilization of the cationic center by

• hyperconjugation and/or fluorine lone pair interaction, resulting in a certain degree of a positive charge of one fluorine atom. Interestingly, at least one phenyl substituent was required to allow the ionization of the starting alcohols into the corresponding carbenium ions. When the aromatic substituent was

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

• ionization and ion mobility), CD spectroscopy and atomic force microscopy, the authors were able to obtain detailed information about the size and secondary structure associated with some of the soluble intermediates. These included: large β-sheet oligomers formed immediately after solubilization (oligomer

Control over size, shape, and photonics of self-assembled organic nanocrystals

• Chen Shahar,
• Yaron Tidhar,
• Yunmin Jung,
• Haim Weissman,
• Sidney R. Cohen,
• Ronit Bitton,
• Iddo Pinkas,
• Gilad Haran and
• Boris Rybtchinski

Beilstein J. Org. Chem. 2021, 17, 42–51, doi:10.3762/bjoc.17.5

• applicability of organic nanocrystals. Experimental General information The 1H and 13C NMR spectra were recorded at 20 °C on a 300 MHz NMR spectrometer (Bruker). Electrospray ionization (ESI) mass spectrometry was performed using a Micromass Platform instrument. UV–vis absorption and fluorescence measurements

Construction of pillar[4]arene[1]quinone–1,10-dibromodecane pseudorotaxanes in solution and in the solid state

• Xinru Sheng,
• Errui Li and
• Feihe Huang

Beilstein J. Org. Chem. 2020, 16, 2954–2959, doi:10.3762/bjoc.16.245

• . Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI–TOF MS) was conducted to investigate the complexation properties. However, no signal related to the complex but only peaks of H were found, implying weak host–guest interactions between H and G (Figures S3 and S4

Synthesis of imidazo[1,5-a]pyridines via cyclocondensation of 2-(aminomethyl)pyridines with electrophilically activated nitroalkanes

• Dmitrii A. Aksenov,
• Nikolai A. Arutiunov,
• Vladimir V. Maliuga,
• Alexander V. Aksenov and
• Michael Rubin

Beilstein J. Org. Chem. 2020, 16, 2903–2910, doi:10.3762/bjoc.16.239

• DMSO-d6, using TMS as an internal standard. High-resolution mass spectra were obtained using a Bruker Maxis spectrometer (electrospray ionization, MeCN solution, using HCO2Na/HCO2H for calibration). Melting points were measured with a Stuart smp30 apparatus. All reactions were performed in oven-dried

A heterobimetallic tetrahedron from a linear platinum(II)-bis(acetylide) metalloligand

• Matthias Hardy,
• Marianne Engeser and
• Arne Lützen

Beilstein J. Org. Chem. 2020, 16, 2701–2708, doi:10.3762/bjoc.16.220

• , correlation of the proton. Low- and high-resolution electrospray ionization mass spectrometry (ESIMS) spectra were recorded on a Bruker Daltonic LTQ Orbitrap XL. The UV–vis spectrum was recorded on a Specord 200 spectrometer (Analytik Jena AG) at ambient temperature. 4-Ethynylaniline (1) [50], trans-[Pt(PBu3

Synthesis and characterization of S,N-heterotetracenes

• Astrid Vogt,
• Florian Henne,
• Christoph Wetzel,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2020, 16, 2636–2644, doi:10.3762/bjoc.16.214

• -heterotetracenes and -hexacene were clearly identified, fully characterized, and their structures confirmed by 1H and 13C NMR spectroscopy and high-resolution mass spectrometry (HRMS) via matrix-assisted laser desorption/ionization (MALDI) (Supporting Information File 1, Figures S1–S5). In the 1H NMR spectra, the

Water-soluble host–guest complexes between fullerenes and a sugar-functionalized tribenzotriquinacene assembling to microspheres

• Si-Yuan Liu,
• Xin-Rui Wang,
• Man-Ping Li,
• Wen-Rong Xu and
• Dietmar Kuck

Beilstein J. Org. Chem. 2020, 16, 2551–2561, doi:10.3762/bjoc.16.207

• ppm in the 13C NMR spectrum were attributed to the acetylene protons and carbons, respectively. The electrospray ionization (ESI) mass spectrum showed the most intense peak at m/z 641.1923, which corresponds to the [M + Na]+ molecular adduct ion and matches well with the calculated value (m/z 641.1935

• Instruments Co., Ltd, Shanghai, China). Mass spectra were recorded using either electrospray ionization (ESI) on a LCMS-IT-TOF instrument (Shimadzu, Kyoto, Japan) or a matrix-assisted laser desorption/ionization (MALDI) on a RapifleX MALDI Tissuetyper system (Bruker Daltonik GmbH, Bremen, Germany). Raman

A new method for the synthesis of diamantane by hydroisomerization of binor-S on treatment with sulfuric acid

• Rishat I. Aminov and
• Ravil I. Khusnutdinov

Beilstein J. Org. Chem. 2020, 16, 2534–2539, doi:10.3762/bjoc.16.205

• × 0.25 mm, helium as the carrier gas, temperature programming from 40 to 300 °С at 8 °C/min, evaporation temperature of 280 °С, ion source temperature of 200 °С, and ionization energy of 70 eV). The elemental composition of the samples was determined on a Carlo Erba 1106 elemental analyzer. The course of

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

• ]. Typically, these analyses are based on mass spectrometry techniques, such as electrospray ionization mass spectrometry (ESIMS) and matrix-assisted laser desorption ionization MS (MALDIMS) [43]. Mass spectrometry techniques are best suited for the determination of the composition of monosaccharide classes

Styryl-based new organic chromophores bearing free amino and azomethine groups: synthesis, photophysical, NLO, and thermal properties

• Anka Utama Putra,
• Deniz Çakmaz,
• Nurgül Seferoğlu,
• Alberto Barsella and
• Zeynel Seferoğlu

Beilstein J. Org. Chem. 2020, 16, 2282–2296, doi:10.3762/bjoc.16.189

• ; doublet, d; doublet-doublet, dd; doublet-triplet, dt; triplet, t; multiplet, m. High-resolution mass spectra (HRMS) were recorded at Gazi University Faculty of Pharmacy using electron ionization (EI) mass spectrometry (Waters-LCT-Premier-XE-LTOF (TOF-MS) instruments; in m/z (rel. %). Elemental analysis

Photosensitized direct C–H fluorination and trifluoromethylation in organic synthesis

• Shahboz Yakubov and
• Joshua P. Barham

Beilstein J. Org. Chem. 2020, 16, 2151–2192, doi:10.3762/bjoc.16.183

• , metabolic stability, adsorption and excretion properties of the compound [16][17]. For example, the pharmacokinetics of drugs are mostly regulated by the balance of the lipophilicity, hydrophilicity and ionization state. Since C–H/C–F substitution in a drug molecule enhances the lipophilicity [18], this has

Clustering and curation of electropherograms: an efficient method for analyzing large cohorts of capillary electrophoresis glycomic profiles for bioprocessing operations

• Ian Walsh,
• Matthew S. F. Choo,
• Sim Lyn Chiin,
• Amelia Mak,
• Shi Jie Tay,
• Pauline M. Rudd,
• Yang Yuansheng,
• Andre Choo,
• Ho Ying Swan and
• Terry Nguyen-Khuong

Beilstein J. Org. Chem. 2020, 16, 2087–2099, doi:10.3762/bjoc.16.176

• of m/z 400–2000 was used, with an acquisition speed of 1 Hz, and the mass spectrometry was set at the following conditions: 2.75 kV electrospray ionization capillary voltage, 15 V cone voltage, 120 °C ion source temperature, 300 °C desolvation temperature, 800 L/h desolvation gas flow. A lockspray

A dynamic combinatorial library for biomimetic recognition of dipeptides in water

• Florian Klepel and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2020, 16, 1588–1595, doi:10.3762/bjoc.16.131

• most significant for FF, followed by YY and AA, respectively (Figure 2b, Scheme 2a). For the first peak, however, the effect of FF is the weakest. This could indicate a selectivity of the binding to the isomer of the second peak, though it is more likely that ionization at the first peak is suppressed

Synthesis and properties of quinazoline-based versatile exciplex-forming compounds

• Rasa Keruckiene,
• Simona Vekteryte,
• Ervinas Urbonas,
• Matas Guzauskas,
• Eigirdas Skuodis,
• Dmytro Volyniuk and
• Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 1142–1153, doi:10.3762/bjoc.16.101

• compounds, based on theoretical calculations and experimental measurements, as well as the electrochemical and thermal properties, are discussed. The synthesized compounds form glasses with glass-transition temperatures ranging from 116 °C to 123 °C. The ionization potentials estimated by cyclic voltammetry

• summarized in Table 1. The ionization potential (IPCV) and electron affinity (EACV) values were estimated accordingly from the oxidation and reduction onset potentials against ferrocene (Eox/Ered,onset vs Fc). The IPCV values demonstrated the similar and collaborative electron-donating effect of the

• the derivatives 1–3 correlated with electrochemically estimated ones and with the ionization potential values discussed above. The photophysical characteristics determined from the UV–vis absorption and photoluminescence spectra are collected in Table 2. The emission spectra of diluted toluene

Palladium-catalyzed regio- and stereoselective synthesis of aryl and 3-indolyl-substituted 4-methylene-3,4-dihydroisoquinolin-1(2H)-ones

• Valeria Nori,
• Antonio Arcadi,
• Armando Carlone,
• Fabio Marinelli and
• Marco Chiarini

Beilstein J. Org. Chem. 2020, 16, 1084–1091, doi:10.3762/bjoc.16.95

• ppm) or tetramethylsilane (δ = 0 ppm). Mass spectrometry was performed using a MALDI–TOF spectrometer AB SCIEX TOF/TOF 5800 system using 3-hydroxycoumarin or α-cyano-4-hydroxycinnamic acid as a matrix in combination with KI for the ionization. Unless otherwise stated, all starting materials, catalysts

Aryl-substituted acridanes as hosts for TADF-based OLEDs

• Naveen Masimukku,
• Dalius Gudeika,
• Oleksandr Bezvikonnyi,
• Ihor Syvorotka,
• Rasa Keruckiene,
• Dmytro Volyniuk and
• Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 989–1000, doi:10.3762/bjoc.16.88

• possessed relatively high thermal stability with glass-transition temperatures being in the range of 79–97 °C. The compounds showed oxidation bands arising from acridanyl groups in the range of 0.31–038 V. Ionization potentials of the solid films ranged from 5.39 to 5.62 eV. The developed materials were

• compounds. During the anodic oxidation sweeps, compounds 3–6 showed single reversible oxidation speaks, which could be tributed to the oxidation of the acridanyl moiety. Also close values of ionization potentials (IPcv) of the compounds 3–6 obtained from the onset potentials of their oxidation signals were

• found in the range of 5.11–5.18 eV. The electron affinity values were deduced from the IPcv and energy gap (Egopt) obtained from the onsets of the UV–vis absorption spectra. The ionization potentials IPPES of the solid films of derivatives 3–6 were estimated by photoelectron emission spectrometry (PES

Aldehydes as powerful initiators for photochemical transformations

• Maria A. Theodoropoulou,
• Nikolaos F. Nikitas and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2020, 16, 833–857, doi:10.3762/bjoc.16.76

• three possible dissociation pathways that can be followed (Scheme 5). Moreover, Reilly and co-workers observed the decomposition of benzaldehyde (8) into benzene (21) and carbon monoxide (22) (reaction (3) in Scheme 5) after the irradiation at 258.9 nm via laser ionization mass spectrometry and