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

• otherwise specified. Gaseous products were determined by a gas chromatograph equipped with two barrier discharge ionization detectors (GC–BID). Typically, the concentrations used for the first screening were: 1 mM for PS, 0.1 mM for catalyst 1, and 20 mM for BIH, and the bases used were either

• from Shimadzu (GC-2030) equipped with two barrier discharge ionization detectors (BID). Every test was repeated at least twice. The photon flux was evaluated with actinometry, according to a previously published procedure [42], and it was 0.025 µE s−1. Therefore, an apparent photoluminescent quantum

Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity

• Swagat K. Mohapatra,
• Khaled Al Kurdi,
• Samik Jhulki,
• Georgii Bogdanov,
• John Bacsa,
• Maxwell Conte,
• Tatiana V. Timofeeva,
• Seth R. Marder and
• Stephen Barlow

Beilstein J. Org. Chem. 2023, 19, 1651–1663, doi:10.3762/bjoc.19.121

• wide range of semiconductors, they must exhibit low ionization energies and thus air sensitivity. One approach to circumvent this issue is to identify systems where the electron-transfer process is coupled to other chemical reactions, increasing the kinetic stability of the dopant to air, and thus

• their Y = cyclohexyl counterparts, 1e+/1e• and 1h+/1h•, respectively. These differences are also similar to those previously seen in the comparison of Y = metallocenyl systems 1c+/1c• and 1d+/1d• with 1e+/1e• (and in the DFT-calculated ionization energies of 1c–e•) [14][50] and are perhaps surprising

Sulfur-containing spiroketals from Breynia disticha and evaluations of their anti-inflammatory effect

• Ken-ichi Nakashima,
• Naohito Abe,
• Masayoshi Oyama,
• Hiroko Murata and
• Makoto Inoue

Beilstein J. Org. Chem. 2023, 19, 1604–1614, doi:10.3762/bjoc.19.117

• electrospray ionization HRESIMS analysis, and quantum chemical electronic CD calculations. Furthermore, the absolute configurations of sugar residues were determined by derivatization of the hydrolysates with ʟ-cysteine methyl ester and o-tolyl isothiocyanate followed by HPLC analysis. The anti-inflammatory

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• , emitted from the surface of polymers [178]. When a high-energy photon impacts an atomic electron, part of the photon energy is transferred to the electron leading to excitation or ionization and radical formation, and a deflected photon with lower energy is emitted, ready to impact another electron. This

Two new lanostanoid glycosides isolated from a Kenyan polypore Fomitopsis carnea

• Winnie Chemutai Sum,
• Sherif S. Ebada,
• Didsanutda Gonkhom,
• Cony Decock,
• Rémy Bertrand Teponno,
• Josphat Clement Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2023, 19, 1161–1169, doi:10.3762/bjoc.19.84

• speed ETD ion trap mass spectrometer (Bruker Daltonics, Bremen, Germany) for HPLC-DAD/MS in positive and negative ionization modes. The HPLC (Dionex UltiMate 3000 UHPLC, Thermo Fisher Scientific Inc., Waltham, MA, USA) system’s stationary phase was composed of a C18 Acquity UPLC BEH column (Waters

• at 0.6 mL/min and the UV–vis detection made at 210 nm and 190–600 nm. The isolates were analyzed on a MaXis ESI-TOF (time-of-flight) mass spectrometer (Bruker Daltonics) for the HRESIMS data, in the positive ionization mode. This was coupled to an Agilent 1260 series HPLC–UV system (Agilent

Synthesis of aliphatic nitriles from cyclobutanone oxime mediated by sulfuryl fluoride (SO₂F₂)

• Xian-Lin Chen and
• Hua-Li Qin

Beilstein J. Org. Chem. 2023, 19, 901–908, doi:10.3762/bjoc.19.68

• nitriles 3ba–da in excellent yields. Interestingly, when the loading of CH3COOK was reduced to 2 equivalents, we obtained a mixture of unsaturated nitrile 3aa and saturated nitrile 4 after column chromatography (Scheme 4). We speculated that the reduction of the base equivalent may induce the ionization of

Recommendations for performing measurements of apparent equilibrium constants of enzyme-catalyzed reactions and for reporting the results of these measurements

• Robert N. Goldberg,
• Robert T. Giessmann,
• Peter J. Halling,
• Carsten Kettner and
• Hans V. Westerhoff

Beilstein J. Org. Chem. 2023, 19, 303–316, doi:10.3762/bjoc.19.26

• has occurred at a microscopic level and from both directions of reaction. Binding, ionization, and reactions that involve the formation of complexes often proceed rapidly. In such cases, the assumption is generally made that equilibrium has been achieved. In any case, any assumption regarding 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

• . Size exclusion chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry were performed to determine the molar mass of the resulting polymers. Our work shows clearly that the solvent is not inert under the conditions typically used for the cationic ring-opening

• 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

• ). Obtained data were processed with Win-GPC software. Matrix-assisted laser desorption/ionization time-of-flight mass spectra (MALDI-TOF MS) were recorded on an Autoflex II (Bruker Daltonics, Bremen, Germany) using an N2 laser (λ = 337 nm). All spectra were recorded in positive reflector mode. Detection was

Improving the accuracy of ³¹P NMR chemical shift calculations by use of scaling methods

• William H. Hersh and
• Tsz-Yeung Chan

Beilstein J. Org. Chem. 2023, 19, 36–56, doi:10.3762/bjoc.19.4

• complicated by water solvation, as well as ionization or aggregation of the phosphoric acid in water, and calculation as a gas-phase chemical shift is also unreasonable [51]. Because of these issues, other studies have used PH3 as an alternative theoretical reference standard [18][19], despite the fact that

Digyalipopeptide A, an antiparasitic cyclic peptide from the Ghanaian Bacillus sp. strain DE2B

• Adwoa P. Nartey,
• Aboagye K. Dofuor,
• Kofi B. A. Owusu,
• Anil S. Camas,
• Hai Deng,
• Marcel Jaspars and
• Kwaku Kyeremeh

Beilstein J. Org. Chem. 2022, 18, 1763–1771, doi:10.3762/bjoc.18.185

• to be C51H89N7O13 based on the high resolution electrospray ionization mass spectrometry (HRESIMSMS) at m/z 1008.6610 for [M + H]+ similar to the calculated value of m/z 1008.6591 with Δ = −1.9 ppm. The molecular formula indicated 11 degrees of unsaturation and the analyses of the 13C NMR spectrum

• and NOESY correlations for compound 1. Liquid chromatography high resolution electrospray ionization mass spectrometry (LC–HRESIMS) sequence tags for compound 1. The absolute stereochemistry of compound 1. Global natural products social molecular networking (GNPS). 1H NMR and 13C NMR spectroscopic

Synthesis of the biologically important dideuterium-labelled adenosine triphosphate analogue ApppI(d₂)

• Petri A. Turhanen

Beilstein J. Org. Chem. 2022, 18, 1466–1470, doi:10.3762/bjoc.18.153

• for the purification of ApppI(d2) [21]. HRMS spectra were recorded on a qTOF mass spectrometer using electrospray ionization (ESI) in negative mode. The purity of the products was determined from the 1H and 31P NMR spectra to be ≥95%, unless stated otherwise. ApppI(d2)⋅3.25 and ⋅5.25 TBA salts: ATP

Characterization of a new fusicoccane-type diterpene synthase and an associated P450 enzyme

• Jia-Hua Huang,
• Jian-Ming Lv,
• Liang-Yan Xiao,
• Qian Xu,
• Fu-Long Lin,
• Gao-Qian Wang,
• Guo-Dong Chen,
• Sheng-Ying Qin,
• Dan Hu and
• Hao Gao

Beilstein J. Org. Chem. 2022, 18, 1396–1402, doi:10.3762/bjoc.18.144

• ionization mass spectrometry (HRESIMS), the molecular formula of 1 was deduced as C20H32, indicating that 1 has five degrees of unsaturation. The 13C NMR spectrum showed that there are four olefinic carbons (δC 153.2, 137.4, 125.1, 118.6) in 1. We thus reasoned that 1 features a tricyclic system

Preparation of an advanced intermediate for the synthesis of leustroducsins and phoslactomycins by heterocycloaddition

• Anaïs Rousseau,
• Guillaume Vincent and
• Cyrille Kouklovsky

Beilstein J. Org. Chem. 2022, 18, 1385–1395, doi:10.3762/bjoc.18.143

• solvent using residual chloroform (7.26 ppm) as an internal reference. 13C NMR spectra were measured at 62.5, 75 or 90 MHz using residual chloroform (77.1 ppm) as an internal reference. High-resolution mass spectrometry (HRMS) analyses were conducted with electro spray ionization (ESI). 6

Cyclodextrin-based Schiff base pro-fragrances: Synthesis and release studies

• Attila Palágyi,
• Jindřich Jindřich,
• Juraj Dian and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2022, 18, 1346–1354, doi:10.3762/bjoc.18.140

• equipped with a flame-ionization detector using a DB624 column). The GC settings were set as follows: detector temperature, 250 °C; column temperature: 160 °C for benzaldehyde and 5-methylfurfural and 120 °C for heptanal. The retention times under the given conditions were 2.1 min for benzaldehyde (2d) and

Experimental and theoretical studies on the synthesis of 1,4,5-trisubstituted pyrrolidine-2,3-diones

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Nguyen Ngoc Tri,
• Luc Van Meervelt,
• Nguyen Tien Trung and
• Wim Dehaen

Beilstein J. Org. Chem. 2022, 18, 1140–1153, doi:10.3762/bjoc.18.118

• spectrometer (Synapt G2 HDMS, Waters, Milford, MA). Samples were infused at 3 μL/min and spectra were obtained in positive (or negative) ionization mode with a resolution of 15000 (FWHM) using leucine enkephalin as lock mass. Besides, exact mass measurements were also recorded on a SCIEX X500 QTOF with

• electrospray ionization (ESI) source in a positive mode. The temperatures of the source were set at 300 °C. Curtain gas (25 psi) chambers were filled with high-purity nitrogen. The capillary voltage was constantly kept at 5500 V. Collision energies was set at 10 V and zero collision energy spread. IDA mode was

Synthesis of N-phenyl- and N-thiazolyl-1H-indazoles by copper-catalyzed intramolecular N-arylation of ortho-chlorinated arylhydrazones

• Yara Cristina Marchioro Barbosa,
• Guilherme Caneppele Paveglio,
• Claudio Martin Pereira de Pereira,
• Sidnei Moura,
• Cristiane Storck Schwalm,
• Gleison Antonio Casagrande and
• Lucas Pizzuti

Beilstein J. Org. Chem. 2022, 18, 1079–1087, doi:10.3762/bjoc.18.110

• electrospray ionization (ESI) source (MicrOTOF-QII, Bruker Scientific) in positive mode. The compounds were individually dissolved in a solution of 50% chromatographic grade MeCN and 50% deionized H2O + 0.1% formic acid. General experimental procedure for the synthesis of hydrazones 1a–i In a 100 mL round

On Reuben G. Jones synthesis of 2-hydroxypyrazines

• Pierre Legrand and
• Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 935–943, doi:10.3762/bjoc.18.93

• description of the experimental set up is provided in Supporting Information File 1. The low-resolution mass spectra were obtained on an Agilent 1200 series LC/MSD system using an Agilent Jet-Stream atmospheric electrospray ionization system and the high-resolution mass spectra (HRMS) were obtained using a

Synthesis of a new water-soluble hexacarboxylated tribenzotriquinacene derivative and its competitive host–guest interaction for drug delivery

• Man-Ping Li,
• Nan Yang and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2022, 18, 539–548, doi:10.3762/bjoc.18.56

• recorded using either the ultrafleXtreme MALDI-TOF mass spectrometer (Bruker) with α-cyano-4-hydroxycinnamic acid (HCCA) as a matrix, or by electrospray ionization (ESI) on a Waters G2-XS QTOF instrument connected to a Waters H-class UPLC equipped with a Waters BEH C18 column using an eluent consisting of

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

• using an OptiMelt automated melting point system. Exact high-resolution mass determinations were analyzed on a JEOL AccuToF 4G LCplus atmospheric pressure ionization time-of-flight mass spectrometer (Jeol, Tokyo, Japan) fitted with direct analysis in real-time (DART) ion source (IonSense DART controller

Cs₂CO₃-Promoted reaction of tertiary bromopropargylic alcohols and phenols in DMF: a novel approach to α-phenoxyketones

• Ol'ga G. Volostnykh,
• Olesya A. Shemyakina,
• Anton V. Stepanov and
• Igor' A. Ushakov

Beilstein J. Org. Chem. 2022, 18, 420–428, doi:10.3762/bjoc.18.44

• , thickness of stationary phase film 0.25 μm; injector temperature 250 °C, gas carrier – helium, flow rate 0.7 mL/min; detector temperature 250 °C; mass analyzer: quadrupole, electron ionization, electron energy: 70 eV, ion source temperature 200 °C; mass range 34–650 Da. The solvent was distilled DMF. Column

Mechanistic studies of the solvolysis of alkanesulfonyl and arenesulfonyl halides

• Malcolm J. D’Souza and
• Dennis N. Kevill

Beilstein J. Org. Chem. 2022, 18, 120–132, doi:10.3762/bjoc.18.13

• , in water as solvent, both electron-supplying and electron-withdrawing substituents decreased the rate of the hydrolysis of benzenesulfonyl chloride. They proposed, consistent with the claim by Hall [12], that with electron-supplying substituents the reaction proceeded, in part, by an ionization (SN1

• simple rationale for the high specific rate of solvolysis observed and a partial changeover to an SN1 pathway was proposed. Vizgert [14][15] had previously suggested that the favored pathway for the hydrolysis of this substrate was by an SN1 ionization mechanism [25]. This proposal was based on the lack

• of acceleration in aqueous dioxane when hydroxide ion was added. As the polarity of the medium is increased, so also is the solvent ionizing power (Y) and the ionization pathway could become of increasing importance and eventually dominant. Forbes and Maskill, first in a communication [26] and then

Bifunctional thiourea-catalyzed asymmetric [3 + 2] annulation reactions of 2-isothiocyanato-1-indanones with barbiturate-based olefins

• Jiang-Song Zhai and
• Da-Ming Du

Beilstein J. Org. Chem. 2022, 18, 25–36, doi:10.3762/bjoc.18.3

• an Agilent 6520 Accurate-Mass Q-TOF MS system equipped with an electrospray ionization (ESI) source. Optical rotations were measured with a Krüss P8000 polarimeter at the indicated concentration with the units of g/100 mL. Enantiomeric excesses were determined by chiral HPLC analysis using an Agilent

Halides as versatile anions in asymmetric anion-binding organocatalysis

• Lukas Schifferer,
• Martin Stinglhamer,
• Kirandeep Kaur and
• Olga García Macheño

Beilstein J. Org. Chem. 2021, 17, 2270–2286, doi:10.3762/bjoc.17.145

• compounds are coordinated to the H-bond catalyst, whereas anion-binding catalysis relies on the formation of an ion pair by binding to the counter-anion of an ionic substrate. The ionization of the corresponding substrate can either occur before the coordination to the anion or the catalyst itself directly

• participates in the ionization step by an anion abstraction-type process (Figure 2b). In the latter approach, the C–X bond cleavage can then either follow a SN1 or SN2 pathway. For enantioselective purposes, solvation of the ion pair is crucial for obtaining high stereoinduction. While more polar solvents give

• 61 was required to form the key aggregate involving two catalyst molecules and the substrate. This complex is the one involved in the rate and enantio-determining ionization step, allowing to furnish the desired products 60 in up to 93% ee. Finally, similar examples utilizing cation–π interactions

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

•  19D). In carbocyclic substrates the displacement of a C–F bond or ionization with a Lewis acid is difficult, but mesylates are stable and suitable for AlMe3 activation. As already mentioned, indoles are an important class of molecules with potential antidiabetic properties since they can act as GPR40

Development of N-F fluorinating agents and their fluorinations: Historical perspective

• Teruo Umemoto,
• Yuhao Yang and
• Gerald B. Hammond

Beilstein J. Org. Chem. 2021, 17, 1752–1813, doi:10.3762/bjoc.17.123