IBD-mediated oxidative cyclization of pyrimidinylhydrazones and concurrent Dimroth rearrangement: Synthesis of [1,2,4]triazolo[1,5-c]pyrimidine derivatives

• Caifei Tang,
• Zhiming Li and
• Quanrui Wang

Beilstein J. Org. Chem. 2013, 9, 2629–2634, doi:10.3762/bjoc.9.298

• for X-ray measurements and G. Tang for acquiring high-resolution mass spectrometry data.

Synthesis of the reported structure of piperazirum using a nitro-Mannich reaction as the key stereochemical determining step

• James C. Anderson,
• Andreas S. Kalogirou,
• Michael J. Porter and
• Graham J. Tizzard

Beilstein J. Org. Chem. 2013, 9, 1737–1744, doi:10.3762/bjoc.9.200

• structure and relative stereochemistry were elucidated by high resolution mass spectrometry, infrared, 1D and 2D NMR spectroscopy [46]. Retrosynthetically we envisaged that the C-3 stereocentre could be set up by hydrogenation from the less hindered face of α-iminolactam 3 or α,β-unsaturated lactam 4

Stability of SG1 nitroxide towards unprotected sugar and lithium salts: a preamble to cellulose modification by nitroxide-mediated graft polymerization

• Guillaume Moreira,
• Laurence Charles,
• Mohamed Major,
• Florence Vacandio,
• Yohann Guillaneuf,
• Catherine Lefay and
• Didier Gigmes

Beilstein J. Org. Chem. 2013, 9, 1589–1600, doi:10.3762/bjoc.9.181

• supporting electrolyte (NaCLO4 or TBAPF6) 0.1 mol·L−1. High-resolution mass spectrometry experiments were performed by using a QStar Elite mass spectrometer (Applied Biosystems SCIEX, Concord, ON, Canada) equipped with an electrospray ionization source operated in the positive mode. The capillary voltage was

Multivalent display of the antimicrobial peptides BP100 and BP143

• Imma Güell,
• Rafael Ferre,
• Kasper K. Sørensen,
• Esther Badosa,
• Iteng Ng-Choi,
• Emilio Montesinos,
• Eduard Bardají,
• Lidia Feliu,
• Knud J. Jensen and
• Marta Planas

Beilstein J. Org. Chem. 2012, 8, 2106–2117, doi:10.3762/bjoc.8.237

• (Bruker Daltonics). High-resolution mass spectrometry (HRMS) was recorded on a Bruker MicroToF-Q MALDI instrument by using a hybrid quadrupole time-of-flight mass spectrometer (University of Zaragoza). Circular dichroism (CD) measurements were obtained using a Jasco spectropolarimeter (J-810, Easton, MD

Copper-catalyzed CuAAC/intramolecular C–H arylation sequence: Synthesis of annulated 1,2,3-triazoles

• Rajkumar Jeyachandran,
• Harish Kumar Potukuchi and
• Lutz Ackermann

Beilstein J. Org. Chem. 2012, 8, 1771–1777, doi:10.3762/bjoc.8.202

• shifts (δ) are given in parts per million (ppm). All IR spectra were taken on a Bruker FTIR Alpha device. MS: EIMS-spectra were recorded with Finnigan MAT 95, 70 eV; high-resolution mass spectrometry (HRMS) with APEX IV 7T FTICR, Bruker Daltonic. Melting points were determined with a Stuart melting-point

Approaches to α-amino acids via rearrangement to electron-deficient nitrogen: Beckmann and Hofmann rearrangements of appropriate carboxyl-protected substrates

• Sosale Chandrasekhar and
• V. Mohana Rao

Beilstein J. Org. Chem. 2012, 8, 1393–1399, doi:10.3762/bjoc.8.161

• fully characterized spectroscopically (including high resolution mass spectrometry, HRMS) apart from X-ray diffraction in the cases mentioned earlier. The final N-benzoyltrioxaadamantylmethylamine products 5 represent α-amino acids which are protected at both the carboxyl and the amine centers. The

Binaphthyl-anchored antibacterial tripeptide derivatives with hydrophobic C-terminal amino acid variations

• John B. Bremner,
• Paul A. Keller,
• Stephen G. Pyne,
• Mark J. Robertson,
• K. Sakthivel,
• Kittiya Somphol,
• Dean Baylis,
• Jonathan A. Coates,
• John Deadman,
• Dharshini Jeevarajah and
• David I. Rhodes

Beilstein J. Org. Chem. 2012, 8, 1265–1270, doi:10.3762/bjoc.8.142

• and high-resolution mass spectrometry. Details of the synthesis and spectral data are given in the experimental section for the representative compound 2c. The experimental and spectroscopic data for all the other compounds are included in Supporting Information File 1. The peptidic dihydrochloride

Stereoselective synthesis of trans-fused iridoid lactones and their identification in the parasitoid wasp Alloxysta victrix, Part II: Iridomyrmecins

• Robert Hilgraf,
• Nicole Zimmermann,
• Lutz Lehmann,
• Armin Tröger and
• Wittko Francke

Beilstein J. Org. Chem. 2012, 8, 1256–1264, doi:10.3762/bjoc.8.141

• ]. Gas chromatography coupled with chemical ionization mass spectrometry (GC/CIMS) proved the molecular mass of the target compounds to be [M]+ = 168, while high resolution mass spectrometry (GC/HRMS) showed their atomic composition to be C10H16O2, confirming the compounds to be isomers of

Stereoselective synthesis of trans-fused iridoid lactones and their identification in the parasitoid wasp Alloxysta victrix, Part I: Dihydronepetalactones

• Nicole Zimmermann,
• Robert Hilgraf,
• Lutz Lehmann,
• Daniel Ibarra and
• Wittko Francke

Beilstein J. Org. Chem. 2012, 8, 1246–1255, doi:10.3762/bjoc.8.140

• analysis (GC/CIMS) showed the molecular mass of the compound to be M+ = 168, while high resolution mass spectrometry (GC/HRMS) proved its atomic composition to be C10H16O2, suggesting an oxygenated monoterpene as the target structure. The fragmentation pattern, exhibited in the 70 eV EI-mass spectrum

Mutational analysis of a phenazine biosynthetic gene cluster in Streptomyces anulatus 9663

• Orwah Saleh,
• Katrin Flinspach,
• Lucia Westrich,
• Andreas Kulik,
• Bertolt Gust,
• Hans-Peter Fiedler and
• Lutz Heide

Beilstein J. Org. Chem. 2012, 8, 501–513, doi:10.3762/bjoc.8.57

• phenazine, termed endophenazine E. The structure of endophenazine E was determined by high-resolution mass spectrometry and by one- and two-dimensional NMR spectroscopy. It represented a conjugate of endophenazine A (9-dimethylallylphenazine-1-carboxylic acid) and L-glutamine (L-Gln), with the carboxyl

• and E during seven days of cultivation is depicted in Figure S1 (Supporting Information File 1). Endophenazine E showed a molecular ion at m/z 421 ([M + H]+). Positive-ion-mode high-resolution mass spectrometry showed an exact mass of 421.186790 Dalton, indicating a molecular formula of C23H24N4O4

A novel high-yield synthesis of aminoacyl p-nitroanilines and aminoacyl 7-amino-4-methylcoumarins: Important synthons for the synthesis of chromogenic/fluorogenic protease substrates

• Xinghua Wu,
• Yu Chen,
• Herve Aloysius and
• Longqin Hu

Beilstein J. Org. Chem. 2011, 7, 1030–1035, doi:10.3762/bjoc.7.117

• performed on a Shimadzu LCMS 2010 system with Chromolith SpeedROD RP-18e column (50 × 4.6 mm) at 1 mL/min with a 10-min gradient of 10–90% acetonitrile containing 0.1% formic acid. High resolution mass spectrometry (HRMS) was performed on a Finnagen LTQ OrbiTrap mass spectrometer. Preparation of an

Multicomponent reaction access to complex quinolines via oxidation of the Povarov adducts

• Esther Vicente-García,
• Rosario Ramón,
• Sara Preciado and
• Rodolfo Lavilla

Beilstein J. Org. Chem. 2011, 7, 980–987, doi:10.3762/bjoc.7.110

• single quantum coherence) and long-range 1H,13C-COSY (HMBC: heteronuclear multiple bond connectivity). IR spectra were recorded using a Thermo Nicolet Nexus spectrometer and are reported in wavenumbers (cm−1). High resolution mass spectrometry was performed by the University of Barcelona Mass

Synthesis and self-assembly of 1-deoxyglucose derivatives as low molecular weight organogelators

• Guijun Wang,
• Hao Yang,
• Sherwin Cheuk and
• Sherman Coleman

Beilstein J. Org. Chem. 2011, 7, 234–242, doi:10.3762/bjoc.7.31

• using a 400 MHz Varian NMR spectrometer. High resolution mass spectrometry data were measured on the Q-Tof of the Mass Spectrometry lab at the University of Illinois after the low resolution masses were confirmed. The ionization technique used was ESI (electrospray ionization). Melting points were

Templated versus non-templated synthesis of benzo-21-crown-7 and the influence of substituents on its complexing properties

• Wei Jiang and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2010, 6, No. 14, doi:10.3762/bjoc.6.14

• coupling constants (J) are in Hertz. The following abbreviations were used for signal multiplicities: s, singlet; d, doublet; t triplet; m, multiplet. Electrospray-ionization time-of-flight high-resolution mass spectrometry (ESI-TOF-HRMS) experiments were conducted on an Agilent 6210 ESI-TOF, Agilent

Prediction of reduction potentials from calculated electron affinities for metal-salen compounds

• Sarah B. Bateni,
• Kellie R. England,
• Anthony T. Galatti,
• Handeep Kaur,
• Victor A. Mendiola,
• Alexander R. Mitchell,
• Michael H. Vu,
• Benjamin F. Gherman and
• James A. Miranda

Beilstein J. Org. Chem. 2009, 5, No. 82, doi:10.3762/bjoc.5.82

• ligand were allowed to reflux for 1 h before the crude metal-salen was recrystallized in 95% ethanol. Each metal-salen was characterized by IR and High Resolution-Mass Spectrometry. Voltammetry: Cyclic Voltammetry was carried out at room temperature at 100 mV s−1 at a glassy carbon electrode in spectral

Synthesis of phosphonate and phostone analogues of ribose-1-phosphates

• Pitak Nasomjai,
• David O'Hagan and
• Alexandra M. Z. Slawin

Beilstein J. Org. Chem. 2009, 5, No. 37, doi:10.3762/bjoc.5.37

• . Infra red (IR) spectra were recorded on Nicolet Avatar 360 FT-IR. High resolution mass spectrometry (HRMS) was carried out using a Micromass LCT (Manchester, UK) mass spectrometer with electrospray ionization (ESI) operating in positive and negative modes. Optical rotations were measured on Perkin-Elmer

Synthesis of rigidified flavin–guanidinium ion conjugates and investigation of their photocatalytic properties

• Harald Schmaderer,
• Mouchumi Bhuyan and
• Burkhard König

Beilstein J. Org. Chem. 2009, 5, No. 26, doi:10.3762/bjoc.5.26

• 35–70 μm, 60 Å from Acros. NMR spectra were recorded at a Bruker Avance 300 spectrometer (300 MHz) or at a Bruker Avance 600 spectrometer (600 MHz). Electrospray ionisation (ES-MS) mass spectra were measured on ThermoQuest Finnigan TSQ 7000 spectrometer. High resolution mass spectrometry (HRMS) was

Synthesis of 2,3,6,7-tetrabromoanthracene

• Christian Schäfer,
• Friederike Herrmann and
• Jochen Mattay

Beilstein J. Org. Chem. 2008, 4, No. 41, doi:10.3762/bjoc.4.41

• -cyclohexadiene as hydrogen donor. In this case, the structure and the purity of 4 were proven by NMR and high resolution mass spectrometry. The UV/VIS-spectra of 2,3,6,7-tetrabromoanthracene and anthracene in cyclohexane are shown in Figure 1. At first glance, both spectra resemble each other; however, all