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

• . The advantages of this chemical method in comparison with other classical methods (e.g., oven drying or similar drying methods) is related to the selectivity for water (no other compounds such as solvents or volatiles will be detected), the controllable analysis temperature (room temperature or a

Effective immobilisation of a metathesis catalyst bearing an ammonium-tagged NHC ligand on various solid supports

• Krzysztof Skowerski,
• Jacek Białecki,
• Stefan J. Czarnocki,
• Karolina Żukowska and
• Karol Grela

Beilstein J. Org. Chem. 2016, 12, 5–15, doi:10.3762/bjoc.12.2

• metathesis (CM) reactions run with only 1 mol % of catalyst. Importantly, the residual ruthenium content in the crude products was very low (determined by ICP-MS method). Reaction work-up was performed solely by filtration of the reaction mixture through a piece of cotton and evaporation of the volatiles, to

Synthesis and structures of ruthenium–NHC complexes and their catalysis in hydrogen transfer reaction

• Chao Chen,
• Chunxin Lu,
• Qing Zheng,
• Shengliang Ni,
• Min Zhang and
• Wanzhi Chen

Beilstein J. Org. Chem. 2015, 11, 1786–1795, doi:10.3762/bjoc.11.194

• volatiles were evaporated under reduced pressure. The residue was washed with water and dried in vacuo. The yellow residue was dissolved in MeCN and concentrated to about 2 mL. The addition of Et2O induced precipitation of the product as a yellow solid. Yield: 190 mg, 53%. Anal. calcd for C16H20F12N8P2Ru: C

• mmol) and triphenylphosphine (262 mg, 1.0 mmol) in 5 mL CH3CN was stirred at 80 °C for 6 h. Then the mixture was filtered through Celite and all volatiles were evaporated under reduced pressure. The residue was washed with ethyl acetate and dried in vacuo. The yellow residue was dissolved in CH3CN and

Synthesis of racemic and chiral BEDT-TTF derivatives possessing hydroxy groups and their achiral and chiral charge transfer complexes

• Sara J. Krivickas,
• Chiho Hashimoto,
• Junya Yoshida,
• Akira Ueda,
• Kazuyuki Takahashi,
• John D. Wallis and
• Hatsumi Mori

Beilstein J. Org. Chem. 2015, 11, 1561–1569, doi:10.3762/bjoc.11.172

• the volatiles removed in vacuo to give the crude enantiopure diacetoxythione (S,S)-15 (32 mg, quantitative). The isolated product was used in the next step without further purification. 1H NMR (300 MHz, CDCl3) δ 2.12 (s, 6H), 3.79 (m, 2H), 4.32 (dd, J = 8.1, 11.4 Hz, 2H), 4.42 (dd, J = 6.0, 11.4 Hz

Preparation of a disulfide-linked precipitative soluble support for solution-phase synthesis of trimeric oligodeoxyribonucleotide 3´-(2-chlorophenylphosphate) building blocks

• Amit M. Jabgunde,
• Alejandro Gimenez Molina,
• Pasi Virta and
• Harri Lönnberg

Beilstein J. Org. Chem. 2015, 11, 1553–1560, doi:10.3762/bjoc.11.171

• precipitate by ESIMS (Table 1). Cleavage from tetravalent soluble support: To the solution of support-bound trimer 9 (0.0061 mmol, 0.045 g) in MeOH (1 mL), triethylamine (1.44 mmol, 0.2 mL) and tris(2-carboxyethyl)phosphine (0.027 mmol, 0.008 g), stirred for 3 h, and then volatiles were removed under reduced

Thermal and oxidative stability of the Ocimum basilicum L. essential oil/β-cyclodextrin supramolecular system

• Daniel I. Hădărugă,
• Nicoleta G. Hădărugă,
• Corina I. Costescu,
• Ioan David and
• Alexandra T. Gruia

Beilstein J. Org. Chem. 2014, 10, 2809–2820, doi:10.3762/bjoc.10.298

• formation was determined by thermal analysis (TG, DSC), FTIR and XRD. The quality of the encapsulation has been studied by gas chromatographic methods. Methylchavicol and other structurally related volatiles were also encapsulated in various natural CDs such as α- and β-CD, as well as in semisynthetic

Solution phase synthesis of short oligoribonucleotides on a precipitative tetrapodal support

• Alejandro Gimenez Molina,
• Amit M. Jabgunde,
• Pasi Virta and
• Harri Lönnberg

Beilstein J. Org. Chem. 2014, 10, 2279–2285, doi:10.3762/bjoc.10.237

• acid-catalyzed methanolysis with HCl in a mixture of MeOH and dioxane. Removal of volatiles under reduced pressure and treatment of the residue with diethyl ether gave the deprotected support (8b) as a white powder. The homogeneity of 8b was verified by RP-HPLC (see Supporting Information File 1). The

Facile synthesis of 1-alkoxy-1H-benzo- and 7-azabenzotriazoles from peptide coupling agents, mechanistic studies, and synthetic applications

• Mahesh K. Lakshman,
• Manish K. Singh,
• Mukesh Kumar,
• Raghu Ram Chamala,
• Vijayender R. Yedulla,
• Domenick Wagner,
• Evan Leung,
• Lijia Yang,
• Asha Matin and
• Sadia Ahmad

Beilstein J. Org. Chem. 2014, 10, 1919–1932, doi:10.3762/bjoc.10.200

• compound was synthesized from Bt-OTs (1.16 g, 4.0 mmol), 1-phenylethanol (580 μL, 4.8 mmol), and DBU (720 μL, 4.8 mmol) in anhydrous THF (20 mL) over 24 h at room temperature. The volatiles were evaporated and the crude material was purified on a silica gel column using 6% EtOAc in hexanes as eluting

Synthesis and bioactivity of analogues of the marine antibiotic tropodithietic acid

• Patrick Rabe,
• Tim A. Klapschinski,
• Nelson L. Brock,
• Christian A. Citron,
• Paul D’Alvise,
• Lone Gram and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2014, 10, 1796–1801, doi:10.3762/bjoc.10.188

• TDA. The introduction of sulfur proceeds via nucleophilic attack of S-thiocysteine to the Michael acceptor of tropone-2-carboxylic acid coenzyme A ester and oxidative elimination of cysteine. The second sulfur atom is introduced by analogous attack to the vinylogous Michael acceptor. The volatiles

Streptopyridines, volatile pyridine alkaloids produced by Streptomyces sp. FORM5

• Ulrike Groenhagen,
• Michael Maczka,
• Jeroen S. Dickschat and
• Stefan Schulz

Beilstein J. Org. Chem. 2014, 10, 1421–1432, doi:10.3762/bjoc.10.146

• and related compounds. We investigated the strain for the production of volatiles using the CLSA (closed-loop stripping analysis) method. Liquid and agar plate cultures revealed the formation of new 2-alkylpyridines (streptopyridines), structurally closely related to the already known 2

• components. In the gas phase, only the streptopyridines could be detected. Therefore, an orthogonal set of analysis is needed to assess the metabolic profile of bacteria, because volatile compounds are obviously overlooked by traditional analytical methods. The streptopyridines are strain specific volatiles

• that are accompanied by a broad range of headspace constituents that occur in many actinomycetes. Volatiles might be of ecological importance for the producing organism, and, as biosynthetic intermediates or shunt products, they can be useful as indicators of antibiotic production in a bacterium

Structure elucidation of female-specific volatiles released by the parasitoid wasp Trichogramma turkestanica (Hymenoptera: Trichogrammatidae)

• Armin Tröger,
• Teris A. van Beek,
• Martinus E. Huigens,
• Isabel M. M. S. Silva,
• Maarten A. Posthumus and
• Wittko Francke

Beilstein J. Org. Chem. 2014, 10, 767–773, doi:10.3762/bjoc.10.72

• -diene and (2E,4E,6S,8S,10S)-4,6,8,10-tetramethyltrideca-2,4-dien-1-ol or their enantiomers as sex specific volatiles. The structures were assigned on the basis of GC–MS investigations using synthetic reference compounds. Keywords: natural products; structure elucidation; sex specific; Trichogramma

Asymmetric total synthesis of a putative sex pheromone component from the parasitoid wasp Trichogramma turkestanica

• Danny Geerdink,
• Jeffrey Buter,
• Teris A. van Beek and
• Adriaan J. Minnaard

Beilstein J. Org. Chem. 2014, 10, 761–766, doi:10.3762/bjoc.10.71

• of 4.4%. Keywords: asymmetric catalysis; copper; deoxypropionates; natural products; sex pheromone; Trichogramma turkestanica; Introduction Communication by means of pheromones is common in many animal species. For instance, many insects secrete air-borne volatiles to attract a mate for generating

• that only virgin females are able to trigger casting behavior in males, which has led to the assumption that virgin females of Trichogramma turkestanica produce a sex pheromone. Analysis of headspace volatiles of virgin females, collected via solid-phase microextraction, showed the presence of two sex

Simple two-step synthesis of 2,4-disubstituted pyrroles and 3,5-disubstituted pyrrole-2-carbonitriles from enones

• Murat Kucukdisli,
• Dorota Ferenc,
• Marcel Heinz,
• Christine Wiebe and
• Till Opatz

Beilstein J. Org. Chem. 2014, 10, 466–470, doi:10.3762/bjoc.10.44

• aminoacetonitrile hydrochloride (1.10 g, 11.76 mmol, 1.48 equiv, 2). The suspension was heated to reflux for 15 h. The mixture was cooled down, diluted with ethyl acetate, washed with saturated aqueous NaHCO3, and dried over anhydrous Na2SO4. All volatiles were removed in vacuo and the crude product was purified by

[²H₂₆]-1-epi-Cubenol, a completely deuterated natural product from Streptomyces griseus

• Christian A. Citron and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 2841–2845, doi:10.3762/bjoc.9.319

• eight to ten days of incubation until fully grown, reflecting the significantly slowed metabolism due to a strong deuterium kinetic isotope effect. After full growth of the culture the volatiles emitted by S. griseus were collected on charcoal traps by use of a closed-loop stripping apparatus (CLSA) [25

• volatiles liquid cultures were inoculated and incubated at 28 °C for 2 d (65.GYM) or 8–10 d (DMM). From these cultures 1 mL was transferred onto agar plates containing the same medium, and incubation was continued for 2 d (65.GYM) or 7–10 d (DMM). The volatile products emitted by the agar plate cultures

• –24 h. The absorbed volatiles were eluted with analytically pure dichloromethane (40–50 μL) and the extract (1 μL) was immediately analyzed by GC–MS. The rest was stored at −80 °C for future reference. GC–MS. GC–MS analyses were carried out on an Agilent 7890A connected with an Agilent 5975C inert

Halogenated volatiles from the fungus Geniculosporium and the actinomycete Streptomyces chartreusis

• Tao Wang,
• Patrick Rabe,
• Christian A. Citron and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 2767–2777, doi:10.3762/bjoc.9.311

• Tao Wang Patrick Rabe Christian A. Citron Jeroen S. Dickschat Institut für Organische Chemie, TU Braunschweig, Hagenring 30, 38106 Braunschweig, Germany 10.3762/bjoc.9.311 Abstract Two unidentified chlorinated volatiles X and Y were detected in headspace extracts of the fungus Geniculosporium

• structure elucidation all possible constitutional isomers for X and Y were obtained by synthesis or from commercial suppliers. Comparison of mass spectra and GC retention times rigorously established the structures of the two chlorinated volatiles. Chlorinated volatiles are not very widespread, but

• brominated or even iodinated volatiles are even more rare. Surprisingly, headspace extracts from Streptomyces chartreusis contained methyl 2-iodobenzoate, a new natural product that adds to the small family of iodinated natural products. Keywords: constitutional isomerism; GC-MS; natural products

New syntheses of 5,6- and 7,8-diaminoquinolines

• Maroš Bella and
• Viktor Milata

Beilstein J. Org. Chem. 2013, 9, 2669–2674, doi:10.3762/bjoc.9.302

• ; N, 18.00. Pyrido[2,3-f]quinoxaline (8). Diimine 7 (113 mg, 0.51 mmol) was added to a stirred solution of hydrochloride 5 (100 mg, 0.51 mmol) in MeOH (8 mL) and stirring was continued at room temperature for 1.5 h. The volatiles were evaporated under reduced pressure and the residue was purified by

Cyclopamine analogs bearing exocyclic methylenes are highly potent and acid-stable inhibitors of hedgehog signaling

• Johann Moschner,
• Anna Chentsova,
• Nicole Eilert,
• Irene Rovardi,
• Philipp Heretsch and
• Athanassios Giannis

Beilstein J. Org. Chem. 2013, 9, 2328–2335, doi:10.3762/bjoc.9.267

• conditions. Therefore, they were exposed to a pH of approximately 1 (MeOH, 1 M HCl) for 24 h. After evaporation of all volatiles, 1H NMR spectra were acquired and compared to the initially obtained spectra of the pure compounds. While compounds 5, 6, 8, and 9 remained unchanged, compounds 19 and 23 showed

Synthesis of axially chiral gold complexes and their applications in asymmetric catalyses

• Yin-wei Sun,
• Qin Xu and
• Min Shi

Beilstein J. Org. Chem. 2013, 9, 2224–2232, doi:10.3762/bjoc.9.261

• functional group of NHT. Experimental Synthesis of NHC–Au(I) complexes (S)-15a and (S)-15b The compound (S)-13 (145 mg, 0.2 mmol) and AuCl·S(Me)2 (59 mg, 0.2 mmol), NaOAc (33 mg, 0.4 mmol) were heated under reflux in CH3CN (2 mL) overnight. The volatiles were then removed under reduced pressure and the

• , 1131, 894, 823, 743, 712, 681 cm−1; HRMS–ESI: [M + NH4]+ calcd for C36H26AuF6IN3, 938.0736; found, 938.0725. Synthesis of chiral P–Au(I) complexes (S)-18 and (S)-22 The compound (S)-17 (454 mg, 1.0 mmol) and AuCl·S(Me)2 (294 mg, 1.0 mmol) were stirred in CH3CN (10 mL) overnight. The volatiles were then

Acid, silver, and solvent-free gold-catalyzed hydrophenoxylation of internal alkynes

• Marcia E. Richard,
• Daniel V. Fraccica,
• Kevin J. Garcia,
• Erica J. Miller,
• Rosa M. Ciccarelli,
• Erin C. Holahan,
• Victoria L. Resh,
• Aakash Shah,
• Peter M. Findeis and
• Robert A. Stockland Jr.

Beilstein J. Org. Chem. 2013, 9, 2002–2008, doi:10.3762/bjoc.9.235

• microwave power (to rapidly heat the sample) lead to significant decomposition (gold metal). After cooling to room temperature, the volatiles were removed, and the title compounds were purified by column chromatography (basic alumina). The arylgold compounds were dissolved in CH2Cl2 and dried over molecular

• column chromatography, dried using molecular sieves (hexane/EtOAc solution), and isolated as oils or powders following removal of the volatiles. Preparation of 4-[[(1Z)-1-butyl-1-hexen-1-yl]oxy]nitrobenzene (16): General procedure B was followed (microwave heating) with 1 (0.0088 g, 0.014 mmol), 5-decyne

Iron-catalyzed decarboxylative alkenylation of cycloalkanes with arylvinyl carboxylic acids via a radical process

• Jincan Zhao,
• Hong Fang,
• Jianlin Han and
• Yi Pan

Beilstein J. Org. Chem. 2013, 9, 1718–1723, doi:10.3762/bjoc.9.197

• ) under a nitrogen atmosphere. Cycloalkane (2.0 mL, 15–25 mmol) and DTBP (di-tert-butyl peroxide, 0.6 mmol, 113 μL) were added under a nitrogen atmosphere and the resulting reaction mixture was stirred at 120 °C for 24 h. After cooling to room temperature and removal of volatiles, the products were

An organocatalytic route to 2-heteroarylmethylene decorated N-arylpyrroles

• Alexandre Jean,
• Jérôme Blanchet,
• Jacques Rouden,
• Jacques Maddaluno and
• Michaël De Paolis

Beilstein J. Org. Chem. 2013, 9, 1480–1486, doi:10.3762/bjoc.9.168

• temperature was introduced DBU (168 μL, 1.12 mmol). The mixture was allowed to react at this temperature for 1 h. Then, the volatiles were removed under reduced pressure and the crude was purified by flash column chromatography (CH2Cl2/MeOH 99:1) on silica gel to yield 5a (432 mg, 99%) as an orange oil. 1H

• extracted with AcOEt (3×), and the combined organic layers were washed with brine, dried over MgSO4, and filtered. The volatiles were removed under reduced pressure to give 58 mg of the crude product, which was purified by flash column chromatography (CH2Cl2/MeOH 99:1) on silica gel to yield 9a (49 mg, 71

Synthesis of guanidinium–sulfonimide ion pairs: towards novel ionic liquid crystals

• Martin Butschies,
• Manuel M. Neidhardt,
• Markus Mansueto,
• Sabine Laschat and
• Stefan Tussetschläger

Beilstein J. Org. Chem. 2013, 9, 1093–1101, doi:10.3762/bjoc.9.121

• was filtered with a Rotilabo-syringe filter. After removal of all volatiles in vacuo, the residue was recrystallized from ethyl acetate to give the pure salts 3a,b. N-(4-(Dodecyloxy)phenyl)-N’,N’,N”,N”-tetramethylguanidinium ((4-(dodecyloxy)phenyl)sulfonyl)((trifluoromethyl)sulfonyl)amide (3a): Yield

Isotopically labeled sulfur compounds and synthetic selenium and tellurium analogues to study sulfur metabolism in marine bacteria

• Nelson L. Brock,
• Christian A. Citron,
• Claudia Zell,
• Martine Berger,
• Irene Wagner-Döbler,
• Jörn Petersen,
• Thorsten Brinkhoff,
• Meinhard Simon and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 942–950, doi:10.3762/bjoc.9.108

• sulfur source for the MeSH volatiles, whereas incorporation of labeling from sulfate was not observed. Moreover, the utilization of selenite and selenate salts by marine alphaproteobacteria for the production of methylated selenium volatiles was explored and resulted in the production of numerous

• methaneselenol-derived volatiles via reduction and methylation. The pathway of selenate/selenite reduction, however, proved to be strictly separated from sulfate reduction. Keywords: dimethylsulfoniopropionate; Roseobacter clade; selenium metabolism; sulfur metabolism; volatiles; Introduction The Roseobacter

• ]. This is reflected by their volatile bouquets that are dominated by sulfur compounds such as polysulfides 1 and 2 (Figure 1), thiosulfonates 3, thioesters 4, or sulfones 5, and phenylacetate-derived volatiles such as the moderately antibacterial compounds tropone (6) and tropone hydrate 7 [3][4][5][6

A peptidic hydrogel that may behave as a “Trojan Horse”

• Nicola Castellucci,
• Giorgio Sartor,
• Natalia Calonghi,
• Carola Parolin,
• Giuseppe Falini and
• Claudia Tomasini

Beilstein J. Org. Chem. 2013, 9, 417–424, doi:10.3762/bjoc.9.44

• solution of Boc-L-Lys(Dansyl)-OBn (0.22 mmol, 0.13 g) and TFA (4.06 mmol, 0.31 mL) in dry dichloromethane (10 mL) was stirred at room temperature for 4 h, then the volatiles were removed under reduced pressure and the corresponding amine salt was obtained pure in quantitative yield without further

• chloride (10 mL) was stirred at room temperature for 4 h, then the volatiles were removed under reduced pressure and the corresponding amine salt was obtained pure in quantitative yield without further purification. A solution of azelaic acid (0.12 mmol, 0.02 g) and HBTU (0.26 mmol, 0.1 g) in dry

N-Heterocyclic carbene–palladium catalysts for the direct arylation of pyrrole derivatives with aryl chlorides

• Ismail Özdemir,
• Nevin Gürbüz,
• Nazan Kaloğlu,
• Öznur Doğan,
• Murat Kaloğlu,
• Christian Bruneau and
• Henri Doucet

Beilstein J. Org. Chem. 2013, 9, 303–312, doi:10.3762/bjoc.9.35

• benzimidazolium salts (10 mmol) in DMSO (5 mL) was added palladium(II) diacetate (5 mmol) under argon, and the resulting mixture was stirred at room temperature for 2 h, then at 60 °C for 4 h, at 80 °C for 2 h and finally at 110 °C for 2 h. Volatiles were removed in vacuo, and the residue was washed twice with