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

Genome mining in Trichoderma viride J1-030: discovery and identification of novel sesquiterpene synthase and its products

• Xiang Sun,
• You-Sheng Cai,
• Yujie Yuan,
• Guangkai Bian,
• Ziling Ye,
• Zixin Deng and
• Tiangang Liu

Beilstein J. Org. Chem. 2019, 15, 2052–2058, doi:10.3762/bjoc.15.202

• by genome mining and determined the structure of its corresponding products. One new 5/6 bicyclic sesquiterpene and its esterified derivative were characterised by GC–MS and 1D and 2D NMR spectroscopy. To the best of our knowledge, this is the first well-identified sesquiterpene synthase from T

• characterised by GC–MS and 1D and 2D NMR, revealing a 5/6 bicyclic sesquiterpene and its C-11 esterified structure. Based on a literature search, to our knowledge, this is the first report of the characterisation of a sesquiterpene synthase in T. viride. In addition, this study demonstrates the effectiveness of

• spectrometry (GC–MS) [30][34]. In vitro assays clearly showed that Tvi09626 could use FPP as its only substrate to produce compound 1 (Figure 3 and Figure S3, Supporting Information File 1). Heterologous expression of Tvi09626 in S. cerevisiae To further verify the function of the putative terpene synthase, a

Analysis of sesquiterpene hydrocarbons in grape berry exocarp (Vitis vinifera L.) using in vivo-labeling and comprehensive two-dimensional gas chromatography–mass spectrometry (GC×GC–MS)

• Philipp P. Könen and
• Matthias Wüst

Beilstein J. Org. Chem. 2019, 15, 1945–1961, doi:10.3762/bjoc.15.190

Morphology-tunable and pH-responsive supramolecular self-assemblies based on AB₂-type host–guest-conjugated amphiphilic molecules for controlled drug delivery

• Yang Bai,
• Cai-ping Liu,
• Di Chen,
• Long-hai Zhuo,
• Huai-tian Bu and
• Wei Tian

Beilstein J. Org. Chem. 2019, 15, 1925–1932, doi:10.3762/bjoc.15.188

• the characteristic signals for BM and propargyl groups in 1H NMR spectrum (Figure S1B-c, Supporting Information File 1), accompanied with the GC–MS results (156.1), indicated the successful preparation of BM-Alk. Finally, the targeted monomer β-CD-BM2 was synthesized through the click reaction between

Metal-free mechanochemical oxidations in Ertalyte^® jars

• Andrea Porcheddu,
• Francesco Delogu,
• Lidia De Luca,
• Claudia Fattuoni and
• Evelina Colacino

Beilstein J. Org. Chem. 2019, 15, 1786–1794, doi:10.3762/bjoc.15.172

• the aldehyde was only detected in negligible amounts (GC–MS analyses). The (diacethoxyiodo)benzene acid (PIDA) allowed to further improve the alcohol-to-aldehyde conversion by a few percentage points (57%), but the formation of 2 equivalents of acetic acid makes it unsuitable for a mechanochemical

• %) and KBr (3.0 mol %) (Table 1, entry 6). Within 20 minutes, the alcohol was completely and selectively oxidized into the corresponding aldehyde (as assessed by GC–MS analyses). The use of NaCl, alone or in combination with NaHCO3, as an adsorbent [58] (Table 1, entries 1–5, 7) or bases (Na2CO3, Table 1

• corresponding ketones proceeded smoothly even without the necessity to use the nitrosyl catalyst (Scheme 6, ketones 17b–19b). With all benzylic alcohols examined, the GC–MS analyses showed that the reactions were nearly complete in about 15 minutes, ketones 17b–19b being isolated in high yields and purities

Different reactivity of phosphorylallenes under the action of Brønsted or Lewis acids: a crucial role of involvement of the P=O group in intra- or intermolecular interactions at the formation of cationic intermediates

• Stanislav V. Lozovskiy,
• Alexander Yu. Ivanov and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2019, 15, 1491–1504, doi:10.3762/bjoc.15.151

• hydrolysis strongly depend on the substituent X on the phosphorus atom. Ions containing a labile P–X bond (X = Cl, O, S), namely A, B, and F–H, gave unstable adducts 2 (registered by GC–MS), which are further transformed into acids 3. The structure of compound 3a was confirmed by X-ray analysis (see

Selenophene-containing heterotriacenes by a C–Se coupling/cyclization reaction

• Pierre-Olivier Schwartz,
• Sebastian Förtsch,
• Astrid Vogt,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2019, 15, 1379–1393, doi:10.3762/bjoc.15.138

• (doublet), t (triplet), m (multiplet). Coupling constants (J) relate to proton-proton couplings. GC–MS measurements were performed on a Shimadzu GCMS-QP2010 SE instrument. Melting points were measured via differential scanning calorimetric measurements (DSC) on a Mettler Toledo DSC823e under argon

One-pot activation–alkynylation–cyclization synthesis of 1,5-diacyl-5-hydroxypyrazolines in a consecutive three-component fashion

• Christina Görgen,
• Katharina Boden,
• Guido J. Reiss,
• Walter Frank and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2019, 15, 1360–1370, doi:10.3762/bjoc.15.136

• diphenylbut-3-yne-1,2-dione (3a) increased from 63 to 76%. The terminal cyclization step, consisting of a Michael addition of benzoyl hydrazide (4b) to diphenylbut-3-yne-1,2-dione (3a) followed by a cyclizing addition of the central hydrazide nitrogen atom to the carbonyl group, was monitored by GC–MS and

Phylogenomic analyses and distribution of terpene synthases among Streptomyces

• Lara Martín-Sánchez,
• Kumar Saurabh Singh,
• Mariana Avalos,
• Gilles P. van Wezel,
• Jeroen S. Dickschat and
• Paolina Garbeva

Beilstein J. Org. Chem. 2019, 15, 1181–1193, doi:10.3762/bjoc.15.115

• culture headspace extracts by GC–MS [31]. Compound 4 was also isolated from in vitro incubations of FPP with the recombinant enzyme and its optical rotation was shown to be opposite to the material from Eucalyptus [32], but the absolute configuration remains unknown. Production of this sesquiterpene by S

Insertion of [1.1.1]propellane into aromatic disulfides

• Robin M. Bär,
• Gregor Heinrich,
• Martin Nieger,
• Olaf Fuhr and
• Stefan Bräse

Beilstein J. Org. Chem. 2019, 15, 1172–1180, doi:10.3762/bjoc.15.114

• reaction conditions was performed (Scheme 2). The screening reaction was set up with 1.0 equiv of diphenyl disulfide (10a) and 1.0 equiv of 1 in diethyl ether at room temperature and the consumption of the starting material was monitored by GC–MS over a period of 1 h (Figure 1). In this first screening

• particularly interesting if the two sulfides of the product can be modified individually. This approach to unsymmetrically substituted BCPs will be further investigated. Optimization of the reaction conditions. The relative conversion was determined by GC–MS. The use of a radical initiator (di-tert-butyl

Novel (2-amino-4-arylimidazolyl)propanoic acids and pyrrolo[1,2-c]imidazoles via the domino reactions of 2-amino-4-arylimidazoles with carbonyl and methylene active compounds

• Victoria V. Lipson,
• Tetiana L. Pavlovska,
• Nataliya V. Svetlichnaya,
• Anna A. Poryvai,
• Nikolay Yu. Gorobets,
• Erik V. Van der Eycken,
• Irina S. Konovalova,
• Svetlana V. Shiskina,
• Alexander V. Borisov,
• Vladimir I. Musatov and
• Alexander V. Mazepa

Beilstein J. Org. Chem. 2019, 15, 1032–1045, doi:10.3762/bjoc.15.101

• as internal standard. The mass spectra were recorded on a Varian 1200L GC–MS instrument, ionization by EI at 70 eV. Fast atom bombardment (FAB) mass spectrometry was performed on a VG 70-70EQ mass spectrometer, equipped with an argon primary atom beam, and a m-nitrobenzyl alcohol matrix was used. LC

Mechanistic investigations on multiproduct β-himachalene synthase from Cryptosporangium arvum

• Jan Rinkel and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2019, 15, 1008–1019, doi:10.3762/bjoc.15.99

• . Whereas the latter diphosphate did not lead to any terpene product, the incubation with FPP showed a smooth conversion into several sesquiterpenes (Figure 1A) with compound 1 as the major peak after GC–MS analysis. However, also the incubations with GPP (Figure 1B) and GGPP (Figure 1C) led to several less

• deprotonation at the same carbon atom gives α-longipinene (6). For the main product 1, the deprotonation was followed by an incubation of HcS and FPPS with (2-2H)GPP [39] and IPP, which resulted in unlabelled 1 as observed by GC–MS (Figure 3). In case of a deprotonation at a methylene group, relevant for the

• formation of compounds 3, 5 and 6, the stereochemical course of these final steps could be followed by stereoselective deuterations. GC–MS analysis of the products obtained from the incubations with HcS, FPPS, DMAPP and (Z)- or (E)-(4-13C,4-2H)IPP showed a specific loss of HZ in all cases (Figure 4

Stereochemical investigations on the biosynthesis of achiral (Z)-γ-bisabolene in Cryptosporangium arvum

• Jan Rinkel and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2019, 15, 789–794, doi:10.3762/bjoc.15.75

• , Supporting Information File 1) and incubated with the common terpene precursors geranyl- (GPP, C10), farnesyl- (FPP, C15), geranylgeranyl- (GGPP, C20) and geranylfarnesyl (GFPP, C25) diphosphate. With hexane extraction and GC–MS analysis, only the incubation with FPP yielded a terpene product (Figure 2) that

• Grignard reaction of geranylacetone with vinylmagnesium bromide. The two NPP samples featuring a well-defined stereocentre, and (rac)-NPP, were incubated with recombinant BbS, the experiments were extracted with hexane and analysed by GC–MS (Figure 3). A selective product formation was observed for the two