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

• optimized conditions the epoxidation of styrene (1a) was stopped at 20% conversion (20 min), the catalyst filtered off and the resulting filtrate was allowed to react for 6 additional hours. Analysis by GC–MS of the crude reaction mixture revealed a conversion of only 33% into styrene oxide (2a), thus

• internal reference. Mass spectra (EI) were obtained at 70 eV on a Agilent HP-7890B GC/MS instrument equipped with a Agilent 5977A selective mass detector. Infrared (FTIR) spectra were obtained on a Nicolet-Nexus spectrophotometer. The purity of volatile compounds and the chromatographic analyses (GC) were

Identification of volatiles from six marine Celeribacter strains

• Anuj Kumar Chhalodia,
• Jan Rinkel,
• Dorota Konvalinkova,
• Jörn Petersen and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 420–430, doi:10.3762/bjoc.17.38

• , Inhoffenstraße 7b, 38124 Braunschweig, Germany 10.3762/bjoc.17.38 Abstract The volatiles emitted from six marine Rhodobacteraceae species of the genus Celeribacter were investigated by GC–MS. Besides several known compounds including dimethyl trisulfide and S-methyl methanethiosulfonate, the sulfur-containing

• Celeribacter strains are capable of methionine and DMSP degradation to widespread sulfur volatiles, but the analysis of trace compounds in natural samples must be taken with care. Keywords: GC–MS; isotopes; Roseobacter; sulfur metabolism; volatiles; Introduction Bacteria from the roseobacter group belong to

• 27375T, C. halophilus DSM 26270T and C. indicus DSM 27257T, were collected through a closed-loop stripping apparatus (CLSA) on charcoal [37]. After extraction with dichloromethane the obtained extracts were analyzed by GC–MS (Figure 1). The compounds were identified by the comparison of the recorded EI

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

• accessible; however, it is possible that important biotransformation products may not to be detected using these techniques. For example, the fluorometabolites detected upon fungal degradation of cyhalothrin were not observed by GC–MS of culture supernatants. When the nature of the degradation products is

• . [110] investigated the bacterial degradation of pentafluorosulfanyl (SF5)-substituted aminophenols and via 19F NMR analysis of culture extracts was able to determine the production of new fluorinated metabolites (Figure 16). Subsequent analysis by GC–MS was required to further characterize the products

Selective synthesis of α-organylthio esters and α-organylthio ketones from β-keto esters and sodium S-organyl sulfurothioates under basic conditions

• Jean C. Kazmierczak,
• Roberta Cargnelutti,
• Thiago Barcellos,
• Claudio C. Silveira and
• Ricardo F. Schumacher

Beilstein J. Org. Chem. 2021, 17, 234–244, doi:10.3762/bjoc.17.24

• results by Bolm et al. [45] and Wang et al. [47], we turned to conduct the reaction under an oxygen atmosphere (Table 1, entry 22). To our delight, the product 3a was obtained selectively in 86% yield. In this case, even GC–MS analysis of the crude sample did not show the presence of 4a. With the best

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

• ® SMP11 melting point apparatus. Reactions were monitored by TLC and GC. Mass spectra were measured via a Thermo Scientific GC/MS DSQ II device, which contained a column: EC-5 30 m × 0.25 mm i.d. × 0.25 µm or using the direct-infusion method using a Waters® ACQUITY® TQD system with a tandem quadrupole

On the mass spectrometric fragmentations of the bacterial sesterterpenes sestermobaraenes A–C

• Anwei Hou and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2020, 16, 2807–2819, doi:10.3762/bjoc.16.231

• enzymatic conversion of the correspondingly 13C-labelled isoprenyl diphosphate precursors with the sestermobaraene synthase from Streptomyces mobaraensis. The main compounds sestermobaraenes A, B, and C were analysed by gas chromatography–mass spectrometry (GC–MS), allowing for a deep mechanistic

• water, simple alcohols. These volatile compounds can efficiently be trapped by specialised methods including the closed-loop stripping apparatus (CLSA) [4] technique or solid-phase microextraction (SPME) [5][6], and then analysed by gas chromatography–mass spectrometry (GC–MS) [7]. Through these and

• allows to identify interesting candidate genes coding for terpene synthases for further studies by genome mining. A major difficulty in the GC–MS-based identification of terpenes is associated with the high similarity of the mass spectra of structurally related terpenes. For this reason, the unambiguous

3-Acetoxy-fatty acid isoprenyl esters from androconia of the ithomiine butterfly Ithomia salapia

• Florian Mann,
• Daiane Szczerbowski,
• Lisa de Silva,
• Melanie McClure,
• Marianne Elias and
• Stefan Schulz

Beilstein J. Org. Chem. 2020, 16, 2776–2787, doi:10.3762/bjoc.16.228

• esters identified in two subspecies, Ithomia salapia aquinia and I. s. derasa. The major components were identified as isoprenyl (3-methyl-3-butenyl) (Z)-3-acetoxy-11-octadecenoate, isoprenyl (Z)-3-acetoxy-13-octadecenoate (12) and isoprenyl 3-acetoxyoctadecanoate (11) by GC/MS and GC/IR analyses

• the wing androconia of I. s. derasa and I. s. aquinia were analyzed by GC/MS. The extracts consisted predominately of fatty acid esters with few other compounds (Table 1). While most ithomiines possess PA-derivatives in the androconia [10][11][12][18][19], only two of the five samples of I. s. aquinia

• formed from hedycaryol (7) during GC/MS analysis by a Cope-rearrangement [20][21], indicating that 7 might be originally present in the hairpencils. That said, we cannot disprove that this rearrangement could also occur in the androconia. Hedycaryol is an early product of sesquiterpene biosynthesis

Synthesis of purines and adenines containing the hexafluoroisopropyl group

• Viacheslav Petrov,
• Rebecca J. Dooley,
• Alexander A. Marchione,
• Elizabeth L. Diaz,
• Brittany S. Clem and
• William Marshall

Beilstein J. Org. Chem. 2020, 16, 2739–2748, doi:10.3762/bjoc.16.224

• (with minimal contribution from such forces as hydrogen bonding or solvent interactions), and the relative enthalpy of activation for each compound (major to minor vs minor to major) are roughly similar to the difference in total enthalpy for the two rotamers for each compound. Experimental GC and GC–MS

Regiodivergent synthesis of functionalized pyrimidines and imidazoles through phenacyl azides in deep eutectic solvents

• Paola Vitale,
• Luciana Cicco,
• Ilaria Cellamare,
• Filippo M. Perna,
• Antonio Salomone and
• Vito Capriati

Beilstein J. Org. Chem. 2020, 16, 1915–1923, doi:10.3762/bjoc.16.158

• are reported in parts per million (δ); CDCl3, (CD3)2CO and (CD3)2SO were used as solvents. GC–MS analyses were performed on a HP 6890 gas chromatograph, Series II by using a HP1 column (methyl siloxane; 30 m × 0.32 mm × 0.25 μm film thickness) equipped with a mass-selective detector operating at 70 eV

Tuneable access to indole, indolone, and cinnoline derivatives from a common 1,4-diketone Michael acceptor

• Dalel El-Marrouki,
• Sabrina Touchet,
• Abderrahmen Abdelli,
• Hédi M’Rabet,
• Mohamed Lotfi Efrit and
• Philippe C. Gros

Beilstein J. Org. Chem. 2020, 16, 1722–1731, doi:10.3762/bjoc.16.144

• 7053 – L2CM) for the HRMS and GC–MS experiments and related discussions. They thank also the Université de Lorraine and the CNRS for their support. Funding The University of Tunis El Manar and the Tunisian Ministry of Higher Education and Scientific Research are acknowledged for a grant to D. M.

Disposable cartridge concept for the on-demand synthesis of turbo Grignards, Knochel–Hauser amides, and magnesium alkoxides

• Mateo Berton,
• Kevin Sheehan,
• Andrea Adamo and
• D. Tyler McQuade

Beilstein J. Org. Chem. 2020, 16, 1343–1356, doi:10.3762/bjoc.16.115

• GC–MS, after being washed with pentane at 0 °C and dried under vacuum, showed no evidence of organic compounds. It seemed that TMPMgCl⋅LiCl coordinated less LiCl than the corresponding iPrMgCl⋅LiCl and triggered LiCl crystallization. To solve this issue, the packed-bed column temperature was decrease

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

• fluorescence quenching studies, UV–vis spectroscopy experiments, calculation of the quantum yield, a cutoff experiment below 400 nm, GC–MS analysis, and NMR spectroscopic mechanistic experiments. They also concluded that an energy transfer mechanism could not be possible since the solvent employed affected the

Photocatalytic deaminative benzylation and alkylation of tetrahydroisoquinolines with N-alkylpyrydinium salts

• David Schönbauer,
• Carlo Sambiagio,
• Timothy Noël and
• Michael Schnürch

Beilstein J. Org. Chem. 2020, 16, 809–817, doi:10.3762/bjoc.16.74

• after 60 h reaction time (34 and 35). For the cyclohexylation the yield was even lower and conversion stopped after 48 h (26%, 36). When [Ru(bpy)3]Cl2 was used as the catalyst, GC–MS analysis of the crude material showed considerably less conversion in comparison. We found that Katritzky salts deriving

Rhodium-catalyzed reductive carbonylation of aryl iodides to arylaldehydes with syngas

• Zhenghui Liu,
• Peng Wang,
• Zhenzhong Yan,
• Suqing Chen,
• Dongkun Yu,
• Xinhui Zhao and
• Tiancheng Mu

Beilstein J. Org. Chem. 2020, 16, 645–656, doi:10.3762/bjoc.16.61

• direct coupling products (namely, benzene and biphenyl) were detected as the main byproducts by GC–MS. This observation also explains why the conversions were always higher than the yields. Effects of ligands Ligands play a decisive role in adjusting the catalytic ability of metal cations [12][13][41][42

• the sources of the carbonyl group and hydrogen in the formyl group. C6H513CHO, C6H5CDO, and C6H513CDO could be verified by the molecular ion peaks at m/z 107, 107, and 108 in the GC–MS spectrum of the reaction solution (for the spectrum, see Supporting Information File 1). This result confirmed that

• by GC–MS to determine the structures of the aromatic aldehyde products. Then, CH2Cl2 (5 mL) was added to the reaction mixture, after which deionized water (10 mL) was added to extract the solvent DMA for 5 times. The organic layer was dried over anhydrous Na2SO4, concentrated by rotary evaporation

Synthesis of disparlure and monachalure enantiomers from 2,3-butanediacetals

• Adam Drop,
• Hubert Wojtasek and
• Bożena Frąckowiak-Wojtasek

Beilstein J. Org. Chem. 2020, 16, 616–620, doi:10.3762/bjoc.16.57

• of the Wittig reaction. Supporting Information Supporting Information File 239: Experimental procedures of the synthesized compounds. Supporting Information File 240: Copies of 1H NMR and 13C NMR spectra. Acknowledgements We thank Dr Marietta Białoń for performing the GC–MS analysis. Funding A.D

KOt-Bu-promoted selective ring-opening N-alkylation of 2-oxazolines to access 2-aminoethyl acetates and N-substituted thiazolidinones

• Qiao Lin,
• Shiling Zhang and
• Bin Li

Beilstein J. Org. Chem. 2020, 16, 492–501, doi:10.3762/bjoc.16.44

• this ring-opening N-alkylation. Then, when this reaction is performed in a mixed solvent system (DMC/H2O 8:2), only 40% yield of the desired product 3a was produced, while no labeled compound was detected by GC–MS in the 18O-labeled experiment (Scheme 7b and c). These important results revealed that

Visible-light-induced addition of carboxymethanide to styrene from monochloroacetic acid

• Kaj M. van Vliet,
• Nicole S. van Leeuwen,
• Albert M. Brouwer and
• Bas de Bruin

Beilstein J. Org. Chem. 2020, 16, 398–408, doi:10.3762/bjoc.16.38

• trapping the radical by replacing styrene with TEMPO (2,2,6,6-tetramethylpiperidin-1-yl)oxyl). However, GC–MS analysis indicated full conversion of TEMPO to the adduct resulting from a radical coupling between a cyanomethanide radical and TEMPO (Scheme 3) for the highly reducing [Ir(ppy)3] (−1.73 V vs SCE

• the desired lactone, according to GC–MS analysis. The 1H NMR and mass spectra of the crude reaction mixture also demonstrated the formation of the ATRA product 4-chloro-4-phenylbutanoic acid. The two products were obtained in a combined yield of 49% (Table 1, entry 4). A further screening of nonpolar

Room-temperature Pd/Ag direct arylation enabled by a radical pathway

• Amy L. Mayhugh and
• Christine K. Luscombe

Beilstein J. Org. Chem. 2020, 16, 384–390, doi:10.3762/bjoc.16.36

• suppressed by the addition of TEMPO and BHT. Moreover, Ph-BHT was observed by GC–MS when BHT was added. Similar to the polymerization trials, coupling was inhibited when the standard conditions were run in the dark. Both the Ph-BHT adduct and continued poor reactivity in the dark provides growing evidence

• published results were replicated, then radical traps were introduced. In these cases, BHT completely eliminated the formation of product 12 and partially inhibited the conversion to product 13. In both cases the arene–BHT adduct was observed by GC–MS as shown in the inset of Scheme 4. While more extensive

p-Pyridinyl oxime carbamates: synthesis, DNA binding, DNA photocleaving activity and theoretical photodegradation studies

• Panagiotis S. Gritzapis,
• Panayiotis C. Varras,
• Nikolaos-Panagiotis Andreou,
• Katerina R. Katsani,
• Konstantinos Dafnopoulos,
• George Psomas,
• Zisis V. Peitsinis,
• Alexandros E. Koumbis and
• Konstantina C. Fylaktakidou

Beilstein J. Org. Chem. 2020, 16, 337–350, doi:10.3762/bjoc.16.33

• from Sigma–Aldrich Co. CT DNA stock solution was prepared according to standard procedures [84]. The CT DNA concentration was determined by the UV absorbance at 260 nm after 1:20 dilution using ε = 6600 M–1cm–1 [85]. High-resolution mass spectra (HRMS) were recorded on micrOTOF GC–MS QP 5050 Shimadzu

Two antibacterial and PPARα/γ-agonistic unsaturated keto fatty acids from a coral-associated actinomycete of the genus Micrococcus

• Amit Raj Sharma,
• Enjuro Harunari,
• Naoya Oku,
• Nobuyasu Matsuura,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 297–304, doi:10.3762/bjoc.16.29

• antimicrobial metabolites from an actinomycete [36] and a basidiomycete fungus [37]. In addition, long-chain saturated fatty acids possessing a keto group were detected in the solvent extract of Legionella by GC–MS analysis [38]. Fatty acid components in fresh water-derived Micrococcus species were

Emission and biosynthesis of volatile terpenoids from the plasmodial slime mold Physarum polycephalum

• Xinlu Chen,
• Tobias G. Köllner,
• Wangdan Xiong,
• Guo Wei and
• Feng Chen

Beilstein J. Org. Chem. 2019, 15, 2872–2880, doi:10.3762/bjoc.15.281

• flakes as nutrient source and subjected to volatile profiling at two time points: 8 days and 18 days after the transfer of plasmodia to a fresh agar plate. Volatiles were collected from the headspace using a solid phase-microextraction fiber and analyzed using gas chromatography–mass spectrometry (GC–MS

• continuous darkness. Headspace collection and GC–MS analysis On the 8th day and 18th day after the transfer of plasmodia to a fresh agar plate, volatiles were collected from the headspace of plasmodia on the agar plate using solid phase microextraction (SPME) (https://www.sigmaaldrich.com). After collection

• analyzed using GC–MS as described for volatile profiling. Plasmodia of P. polycephalum emit a mixture of volatiles predominated by terpenoids. A) GC chromatograms of volatiles collected from plasmodia of P. polycephalum grown at 8 and 18 days after transferring to a fresh agar plate. This experiment was

In water multicomponent synthesis of low-molecular-mass 4,7-dihydrotetrazolo[1,5-a]pyrimidines

• Irina G. Tkachenko,
• Sergey A. Komykhov,
• Vladimir I. Musatov,
• Svitlana V. Shishkina,
• Viktoriya V. Dyakonenko,
• Vladimir N. Shvets,
• Mikhail V. Diachkov,
• Valentyn A. Chebanov and
• Sergey M. Desenko

Beilstein J. Org. Chem. 2019, 15, 2390–2397, doi:10.3762/bjoc.15.231

• spectra were measured on a GC–MS Varian 1200L (ionizing voltage 70 eV, direct input of the sample) instrument. Elemental analysis was realized on a EuroVector EA-3000. Analytical samples of the compounds were obtained by crystallization from water and further drying at room temperature in air. Microwave

Thermal stability of N-heterocycle-stabilized iodanes – a systematic investigation

• Andreas Boelke,
• Yulia A. Vlasenko,
• Mekhman S. Yusubov,
• Boris J. Nachtsheim and
• Pavel S. Postnikov

Beilstein J. Org. Chem. 2019, 15, 2311–2318, doi:10.3762/bjoc.15.223

• cyclic (33) diaryliodonium salt. Pseudocyclic salt 25 was heated to 185 °C and the resulting oily residue was analyzed by GC–MS (Scheme 1a). Besides dearylation to aryl iodide 25a we observed the formation of an N-arylated product 25b in significant amounts. In a similar experiment compound 33 was heated

Harnessing enzyme plasticity for the synthesis of oxygenated sesquiterpenoids

• Melodi Demiray,
• David J. Miller and
• Rudolf K. Allemann

Beilstein J. Org. Chem. 2019, 15, 2184–2190, doi:10.3762/bjoc.15.215

• ]. Both of these alcohols were methylated with methyl iodide to yield 16 and 17 [32]. To produce the final FDP analogues, THP was removed to generate alcohols 18 and 19, and subsequently diphosphorylated via halogenated intermediates (Scheme 2 and Supporting Information File 1) [33][34][35]. GC–MS

• (21) (Scheme 3B). Due to the racemic nature of the starting diphosphate 11b it is, however, also possible that each enzymatic product arises independently from the individual enantiomers. GC–MS analysis of the organic soluble products generated from an incubation of ADS with 12-methoxy-FDP (12

Regioselective Pd-catalyzed direct C1- and C2-arylations of lilolidine for the access to 5,6-dihydropyrrolo[3,2,1-ij]quinoline derivatives

• Hai-Yun Huang,
• Haoran Li,
• Thierry Roisnel,
• Jean-François Soulé and
• Henri Doucet

Beilstein J. Org. Chem. 2019, 15, 2069–2075, doi:10.3762/bjoc.15.204

• lilolidines were detected in very low yields by GC–MS analysis of the crude mixtures. The structure of 20 was confirmed by X-ray diffraction. As α-arylated lilolidines can be easily obtained under the reaction conditions shown in Scheme 2, the synthesis of α,β-diarylated 5,6-dihydropyrrolo[3,2,1-ij]quinolines