The reductive decyanation reaction: an overview and recent developments

• Jean-Marc R. Mattalia

Beilstein J. Org. Chem. 2017, 13, 267–284, doi:10.3762/bjoc.13.30

• reduction by NaH [81]. Reductive decyanation catalyzed by nickel nanoparticles. Yields are given in weight % from GC–MS data [85]. Decyanation of 2-cyanobenzo[b]thiophene [87]. Simplified pathways involved in transition-metal-promoted reductive decyanations [93][95]. Fe-catalyzed reductive decyanation

• A, 14 examples, yield ≥ 20% and 1 synthetic application; method B, 12 examples, yield ≥ 17% and 1 synthetic application). Yields determined by GC–MS and 1H NMR spectroscopy [106][107]. Proposed catalytic cycle for the nickel complex 58 catalyzed decyanation (method A). Only the cycle for 63 is shown

Diels–Alder reactions of myrcene using intensified continuous-flow reactors

• Christian H. Hornung,
• Miguel Á. Álvarez-Diéguez,
• Thomas M. Kohl and
• John Tsanaktsidis

Beilstein J. Org. Chem. 2017, 13, 120–126, doi:10.3762/bjoc.13.15

• analyzed by GC–FID and GC–MS; details for both can be found in Supporting Information File 1. The GC–FID results were also used to confirm NMR conversions and to calculate GC-based yields. Batch Diels–Alder reaction The following procedure is typical for the preparation of the Diels–Alder adduct of myrcene

Direct arylation catalysis with chloro[8-(dimesitylboryl)quinoline-κN]copper(I)

• Sem Raj Tamang and
• James D. Hoefelmeyer

Beilstein J. Org. Chem. 2016, 12, 2757–2762, doi:10.3762/bjoc.12.272

• equivalents KO(t-Bu) (Table 1, entry 1). After 10 hours the yield of biphenyl was 94% according to GC–MS analysis. A control reaction (Table 1, entry 4) of iodobenzene with benzene/DMF (10:1 v/v) using 2 mol % Cu(I)Br and 30 equivalents KO(t-Bu) gave 5% yield of biphenyl after 10 hours. Reactions performed in

• heterocoupling pathway. The coupling of benzene with p-iodoanisole at 2 mol % loading of catalyst 2 was evaluated (Table 1, entry 2). We were pleased to find that the reaction yielded 4-methoxybiphenyl according to GC–MS analysis, and the isolated yield after flash column chromatography was 77%. Encouraged by

• ]. All organic reagents and solvents were obtained from commercial sources and used without further purification. A GCMS-QP2010SE gas chromatograph–mass spectrometer (Shimadzu Corp., Kyoto, Japan) was used for GC–MS analyses. NMR spectra were recorded on an Avance 400 MHz spectrometer (Bruker, Billerica

Identification, synthesis and mass spectrometry of a macrolide from the African reed frog Hyperolius cinnamomeoventris

• Markus Menke,
• Pardha Saradhi Peram,
• Iris Starnberger,
• Walter Hödl,
• Gregory F.M. Jongsma,
• David C. Blackburn,
• Mark-Oliver Rödel,
• Miguel Vences and
• Stefan Schulz

Beilstein J. Org. Chem. 2016, 12, 2731–2738, doi:10.3762/bjoc.12.269

• synthesis of the identified compounds for biological testing. Because of the small amount of natural material available, only GC–MS investigations can be used to identify the compounds. The analysis revealed unsaturated macrocyclic lactones to be major constituents of the secretion of the cinnamon-bellied

• EI mass spectra of unsaturated macrolactones, and 3) show how ring-closing metathesis reaction conditions can be selected to obtain either pure compounds or a library of compounds useful for evaluation of their mass spectra. Results and Discussion The GC–MS analysis of a gular gland extract of

• isomerized mixtures constitute a library of closely related macrolides differing slightly in position of double bonds and ring size. With the diagnostic mass spectrometric ions discussed above, each compound can be assigned a structure after GC–MS analysis. These mass spectra together with the gas

From betaines to anionic N-heterocyclic carbenes. Borane, gold, rhodium, and nickel complexes starting from an imidazoliumphenolate and its carbene tautomer

• Ming Liu,
• Jan C. Namyslo,
• Martin Nieger,
• Mika Polamo and
• Andreas Schmidt

Beilstein J. Org. Chem. 2016, 12, 2673–2681, doi:10.3762/bjoc.12.264

• range of 400 to 4000 cm−1. The mass spectra were obtained with a Varian 320 MS Triple Quad GC/MS/MS instrument with a Varian 450-GC. All electrospray ionisation mass spectra (ESIMS) were measured with a Hewlett-Packard/Agilent LCMSD series HP 1100 spectrometer with APIES. The compound samples were

A detailed view on 1,8-cineol biosynthesis by Streptomyces clavuligerus

• Jan Rinkel,
• Patrick Rabe,
• Laura zur Horst and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2016, 12, 2317–2324, doi:10.3762/bjoc.12.225

• chromatography and used to convert both (R)- and (S)-(1-2H)GPP into (2H)-1 (in agreement with the findings described in reference [28], 1 is the only product from unlabelled GPP as was shown by GC–MS, Figure S2, Supporting Information File 1). The obtained products were analysed by HSQC spectroscopy (Figure 2

• , overlaid with 400 μL (2H6)benzene and further incubated overnight. The organic phase was separated, dried over MgSO4 and directly analysed by GC–MS and NMR. Incubation experiment with (2-13C)GPP Enzyme purification starting from an E. coli expression culture (0.5 L) was performed as described above. The

• was analysed directly by GC–MS and NMR. NMR spectroscopy To record NMR spectra, instruments AV Avance DMX-500 (500 MHz), DPX-400 (400 MHz) and AV III HD Cryo (700 MHz) from Bruker were used. Solvent signals were used to reference the spectra (1H NMR, residual proton signals: (2H6)benzene δ = 7.16; 13C

Tunable microwave-assisted method for the solvent-free and catalyst-free peracetylation of natural products

• Manuela Oliverio,
• Paola Costanzo,
• Monica Nardi,
• Carla Calandruccio,
• Raffaele Salerno and
• Antonio Procopio

Beilstein J. Org. Chem. 2016, 12, 2222–2233, doi:10.3762/bjoc.12.214

• activated and gave rise to moderate yields as in a typical equilibrium system. The reactions were monitored by TLC or GC–MS until the reagent disappeared and the work-up procedure was optimized in order to minimize the wastes of the process. Namely the reaction mixture was reacted with ethanol in order to

• quantitative conversion was registered and the obtained mixture of different acetylated derivatives was fully identified by GC–MS (see Supporting Information File 1). In this last case the change of the P-program was ineffective in increasing the yield of 9a in respect to the other acetylated forms (data not

• seal. Reactions were monitored by TLC using silica plates 60-F264 on alumina, commercially available from Merk. GC–MS spectra were recorded on a GC–MS Thermo Scientific workstation, formed by a Focus GC (30-m VARIAN-VF-5ms, 0.25 mm diameter capillary column, working on spitless mode, 1.2 mL/min He as

Regiocontroled Pd-catalysed C5-arylation of 3-substituted thiophene derivatives using a bromo-substituent as blocking group

• Mariem Brahim,
• Hamed Ben Ammar,
• Jean-François Soulé and
• Henri Doucet

Beilstein J. Org. Chem. 2016, 12, 2197–2203, doi:10.3762/bjoc.12.210

• expected coupling products 2–4 were obtained in moderate yields. On the other hand, with 4-bromoanisole as an electron-rich aryl bromide, the desired C5-arylated 2-bromothiophene could not be detected by GC–MS analysis of the crude mixture, and a large amount of unreacted 4-bromoanisole was recovered

Comparing blends and blocks: Synthesis of partially fluorinated diblock polythiophene copolymers to investigate the thermal stability of optical and morphological properties

• Pierre Boufflet,
• Sebastian Wood,
• Jessica Wade,
• Zhuping Fei,
• Ji-Seon Kim and
• Martin Heeney

Beilstein J. Org. Chem. 2016, 12, 2150–2163, doi:10.3762/bjoc.12.205

• THF) dropwise. After 30 min, the resulting Grignard monomer solution (0.28 M in THF) was ready for use as indicated by the near total consumption of starting material (<3% remaining by quenching a sample with methanol and analysing by GC–MS). Synthesis of P3OT-b-F-P3OT 2:1 In a sealed dry 2–5 mL

Solvent-free synthesis of novel para-menthane-3,8-diol ester derivatives from citronellal using a polymer-supported scandium triflate catalyst

• Lubabalo Mafu,
• Ben Zeelie and
• Paul Watts

Beilstein J. Org. Chem. 2016, 12, 2046–2054, doi:10.3762/bjoc.12.193

• C0 = quaternary carbon. Gas chromatography (GC–MS) spectrometry was performed on a HP F5890 series LL plus gas chromatograph coupled to an HP 5972 series mass selective detector. The GC was equipped with a HP-5 MS capillary column (30 mm × 0.25 mm i.d.) and ultra-high purity helium (99.999%) carrier

• : NMR, IR and GC–MS spectra of synthesized compounds. Acknowledgements We wish to thank InnoVenton: Institute of Chemical Technology and the National Research Fund (NRF) for their financial support.

Practical synthetic strategies towards lipophilic 6-iodotetrahydroquinolines and -dihydroquinolines

• David R. Chisholm,
• Garr-Layy Zhou,
• Ehmke Pohl,
• Roy Valentine and
• Andrew Whiting

Beilstein J. Org. Chem. 2016, 12, 1851–1862, doi:10.3762/bjoc.12.174

• %) according to GC–MS analysis, and the iodinated product 2 was difficult to isolate by chromatography. In light of these results, bromination was conducted with the aim of synthesising the corresponding aryl iodide 2 by halogen exchange (Scheme 3). After careful optimisation of the reaction conditions, the

Mechanistic investigations on six bacterial terpene cyclases

• Patrick Rabe,
• Thomas Schmitz and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2016, 12, 1839–1850, doi:10.3762/bjoc.12.173

• cloning by homologous recombination in yeast, followed by the heterologous expression in Escherichia coli, direct headspace sampling using a closed-loop stripping apparatus (CLSA) and compound identification by GC–MS [32][33]. Here we report on the purification of six of these bacterial sesquiterpene

• , Figure 1) by GC–MS analysis (Figure S1, Supporting Information File 1) [32], while the enzyme incubations with geranyl diphosphate (GPP) and geranylgeranyl diphosphate (GGPP) gave no products. Although 1 was isolated from vetiver oil (Vetiveria zizanioides, Gramineae) nearly five decades ago [38], the

• identified as T-muurolol by GC–MS [32], besides minor amounts of α-muurolene and δ-cadinene (Figure S1, Supporting Information File 1). The 13C NMR and 13C-DEPT135 spectra of purified 2 exhibited signals for four methyl groups, four methylene groups, five methine (four sp3-CH and one sp2-CH) as well as two

Cross-linked cyclodextrin-based material for treatment of metals and organic substances present in industrial discharge waters

• Élise Euvrard,
• Nadia Morin-Crini,
• Coline Druart,
• Justine Bugnet,
• Bernard Martel,
• Cesare Cosentino,
• Virginie Moutarlier and
• Grégorio Crini

Beilstein J. Org. Chem. 2016, 12, 1826–1838, doi:10.3762/bjoc.12.172

• of the sixteen PAHs was performed by liquid–liquid extraction with hexane followed by separation and detection on a system composed of a GC apparatus and a triple quadrupole spectrometer (GC-MS/MS, Agilent, Massy, France) according to a method described in detail by Crini and co-workers [36]. Three

• APs (4NP, 4nNP, 4tOP) were analyzed by a certified laboratory (CARSO LSEHL, Lyon, France), by liquid–liquid extraction followed by separation and detection on GC-MS/MS according to the standard NF EN ISO 18857-1. For the detailed analysis, 189 substances and 17 water parameters were analyzed, before

One-pot synthesis of 4′-alkyl-4-cyanobiaryls on the basis of the terephthalonitrile dianion and neutral aromatic nitrile cross-coupling

• Roman Yu. Peshkov,
• Elena V. Panteleeva,
• Wang Chunyan,
• Evgeny V. Tretyakov and
• Vitalij D. Shteingarts

Beilstein J. Org. Chem. 2016, 12, 1577–1584, doi:10.3762/bjoc.12.153

• )pentane – but the reaction mixture contained traces of compounds with molar masses of 325 and 352 (<1.5% according to GC–MS), which can be attributed to 4'-(5-phenylpentyl)-[1,1'-biphenyl]-4-carbonitrile and 4'-(5-(1-cyanocyclohexa-2,5-dien-1-yl)pentyl)-[1,1'-biphenyl]-4-carbonitrile, respectively. The

Microwave-assisted synthesis of (aminomethylene)bisphosphine oxides and (aminomethylene)bisphosphonates by a three-component condensation

• Erika Bálint,
• Ádám Tajti,
• Anna Dzielak,
• Gerhard Hägele and
• György Keglevich

Beilstein J. Org. Chem. 2016, 12, 1493–1502, doi:10.3762/bjoc.12.146

• 1 and 6, 7). The transesterified by-products (9-11 and 3c) were indentified by GC–MS (Figure 2) or LC–MS, and were proved by HRMS (Table 7). The composition of the reaction mixture for the experiment marked by Table 6, entry 6 was analyzed by 31P NMR (see Figure 3). It was observed that increasing

• , except two, all of them are new compounds. Furthermore, a few intermediates supporting the mechanism of the condensation, and several by-products were also identified. Effect of the quantity of dimethyl phosphite (DMP) on the product composition (from Table 6, entries 1–5.) GC–MS chromatogram for the

The hydrolysis of geminal ethers: a kinetic appraisal of orthoesters and ketals

• Sonia L. Repetto,
• James F. Costello,
• Craig P. Butts,
• Joseph K. W. Lam and
• Norman M. Ratcliffe

Beilstein J. Org. Chem. 2016, 12, 1467–1475, doi:10.3762/bjoc.12.143

• . HRMS–ESI calculated for [M + Na]+ 169.0835, found: 169.0836. The distribution of products resulting from the exchange reaction of 6 with dl- and meso-2,3-butanediol warrants brief comment; reaction of the former affords 10 [43], whereas the latter gives C(2) epimers 11 and 14. Both GC–MS and 1H NMR

The EIMS fragmentation mechanisms of the sesquiterpenes corvol ethers A and B, epi-cubebol and isodauc-8-en-11-ol

• Patrick Rabe and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2016, 12, 1380–1394, doi:10.3762/bjoc.12.132

• bacterial terpene cyclases corvol ether synthase from Kitasatospora setae, the epi-cubebol synthase from Streptosporangium roseum, and the isodauc-8-en-11-ol synthase from Streptomyces venezuelae. The enzyme products were analysed by GC–MS and GC–QTOF MS2 and the obtained data were used to delineate the

• standard. Furthermore, various high quality databases containing the EI mass spectra and retention indices of thousands of compounds are available that assist in automated compound identification [2][3]. If unknown compounds are detected in natural extracts, their structure elucidation by GC–MS is more

• . venezuelae ATCC 10712 [21], respectively. In previous work all used enzymes were mechanistically thoroughly studied, and therefore the locations of labellings in the obtained products are known [18][19][20][21][22]. The enzyme products were analysed via GC–MS, and for each of the 13C-labelled isotopomers of

Efficient syntheses of climate relevant isoprene nitrates and (1R,5S)-(−)-myrtenol nitrate

• Sean P. Bew,
• Glyn D. Hiatt-Gipson,
• Graham P. Mills and
• Claire E. Reeves

Beilstein J. Org. Chem. 2016, 12, 1081–1095, doi:10.3762/bjoc.12.103

• compared to the starting materials as well as GC–MS analysis (negative ion mode) corroborated the O-nitrate ester groups were present. Although the use of silver nitrate had been validated in our ‘test’ reaction, the use of isoprene as a starting material was clearly not as convenient as first envisaged

A convenient route to symmetrically and unsymmetrically substituted 3,5-diaryl-2,4,6-trimethylpyridines via Suzuki–Miyaura cross-coupling reaction

• Dariusz Błachut,
• Joanna Szawkało and
• Zbigniew Czarnocki

Beilstein J. Org. Chem. 2016, 12, 835–845, doi:10.3762/bjoc.12.82

• halogenated pyridines and pyrimidines. During our search for new "route markers" of amphetamine analogues synthesized by the Leuckart method, we focused our attention on two groups of heterocycles, that were preliminary identified by GC–MS analysis as 3,4,5-triaryl-2,6-dimethylpyridines P5 [32][33] and 3,5

• ratio of was analysed by GC–MS (Table 1, entries 4–9). Full conversion of the starting material 1 was accomplished within 1 hour. However, the transformation of intermediary bromophenylpyridine 3 into 4 required further 15 hours. It was observed that during the last hour of the reaction, a significant

• applied. The best outcome in terms of the reaction time, yield of the diarylated product 4 and the content of byproducts were obtained using Pd(OAc)2 as palladium source and Buchwald ligands S-Phos and X-Phos [53][54][55] in toluene in the presence of K3PO4. As it was shown by GC–MS, full conversion of

A practical way to synthesize chiral fluoro-containing polyhydro-2H-chromenes from monoterpenoids

• Oksana S. Mikhalchenko,
• Dina V. Korchagina,
• Konstantin P. Volcho and
• Nariman F. Salakhutdinov

Beilstein J. Org. Chem. 2016, 12, 648–653, doi:10.3762/bjoc.12.64

• (61%). These conditions (Table 1, entry 6) were chosen as suitable for further research. Preparative production under the chosen conditions provided 72% of 8a by GC–MS and after separation by column chromatography the target fluorinated product 8a was isolated in 69% yield; the yield of compound 2a

Supported bifunctional thioureas as recoverable and reusable catalysts for enantioselective nitro-Michael reactions

• José M. Andrés,
• Miriam Ceballos,
• Alicia Maestro,
• Isabel Sanz and
• Rafael Pedrosa

Beilstein J. Org. Chem. 2016, 12, 628–635, doi:10.3762/bjoc.12.61

• , analytical columns (250 × 4.6 mm) by using mixture of n-hexane/isopropanol as eluent. UV detection was monitored at 220 or at 254 nm. ESI mass spectra were obtained on an Agilent 5973 inert GC/MS system. Commercially available organic and inorganic compounds were used without further purification. Solvents

Antibiotics from predatory bacteria

• Juliane Korp,
• María S. Vela Gurovic and
• Markus Nett

Beilstein J. Org. Chem. 2016, 12, 594–607, doi:10.3762/bjoc.12.58

• associated pathway, (+)-O-methylkolavelool was identified as a metabolic product. Subsequent GC–MS analyses confirmed that this previously unknown diterpene is actually produced by the predatory bacterium [128]. From genomic data, it is evident that the genus Herpetosiphon harbors a significant potential for

Natural products from microbes associated with insects

• Christine Beemelmanns,
• Huijuan Guo,
• Maja Rischer and
• Michael Poulsen

Beilstein J. Org. Chem. 2016, 12, 314–327, doi:10.3762/bjoc.12.34

• on the outer cocoon surface. Subsequent gas chromatography–mass spectrometry (GC–MS) analyses and expression studies revealed that the production of both antibiotics peaked within the first two weeks after cocoon spinning [45]. Although expression levels decreased shortly afterwards, the antibiotic

Thermal and oxidative stability of Atlantic salmon oil (Salmo salar L.) and complexation with β-cyclodextrin

• Daniel I. Hădărugă,
• Mustafa Ünlüsayin,
• Alexandra T. Gruia,
• Cristina Birău (Mitroi),
• Gerlinde Rusu and
• Nicoleta G. Hădărugă

Beilstein J. Org. Chem. 2016, 12, 179–191, doi:10.3762/bjoc.12.20

• FAs (and the corresponding glycerides) are easily degraded by oxidation, especially at higher temperatures. An appropriate method for evaluating the overall FA profile is the gas chromatography–mass spectrometry (GC–MS) analysis of the FAs, derivatized to the corresponding methyl esters. The relative

• triglycerides from ASO of 899.5 g/mol (according to GC–MS analysis) and 1310 g/mol for β-CD hydrate (according to KFT analysis of water content of commercial β-CD). First, 1 mmol (or 3 mmol) of β-CD hydrate (1.313 ± 0.0007 g or 3.939 ± 0.0004 g) was suspended in 12 mL of distilled water and heated to 50 °C in

• mixture was thoroughly milled for 15 min. Afterwards the mixture was cooled to room temperature, washed with ethanol (1 mL) to remove surface oil, and dried to constant mass in a desiccator over MS 4Å. The kneaded complexes were prepared in duplicates. GC–MS analysis of the raw and degraded ASO The FA

Copper-catalyzed arylation of alkyl halides with arylaluminum reagents

• Bijay Shrestha and
• Ramesh Giri

Beilstein J. Org. Chem. 2015, 11, 2400–2407, doi:10.3762/bjoc.11.261

• , 22.8, 29.4, 29.5, 29.6, 31.7, 32.0, 36.1, 125.7, 128.3, 128.5, 143.1; GC–MS (m/z) 190.1. 1-Dodecyl-3-methylbenzene (4): The title compound 4 was obtained as yellow oil (159 mg, 61% yield) after purification by silica gel column chromatography. 1H NMR (300 MHz, CDCl3) δ 0.90 (t, J = 6.3 Hz, 3H), 1.28

• –1.31 (m, 18H), 1.53–1.64 (m, 2H), 2.35 (s, 3H), 2.55–2.60 (m, 2H), 6.99–7.02 (m, 3H), 7.18 (t, J = 6.9 Hz, 1H); 13C NMR (75 MHz, CDCl3) δ 14.3, 21.6, 22.9, 27.1, 29.5, 29.6, 29.7, 29.8, 31.7, 32.1, 36.1, 45.3, 125.5, 126.4, 128.3, 129.4, 137.9, 143.1; GC–MS (m/z) 260.1. 1-Isopentyl-3-methoxybenzene (5

• , 33.9, 40.8, 55.2, 110.9, 114.3, 120.9, 129.3, 144.9, 159.7; GC–MS (m/z) 178.1. 7-Octen-1-ylbenzene (6) [63]: The title compound 6 was obtained as a colorless oil (113 mg, 60% yield) after purification by silica gel column chromatography. 1H NMR (300 MHz, CDCl3) δ 1.33–1.41 (m, 6H), 1.60–1.65 (m, 2H