Synthesis and characterization of a hyper-branched water-soluble β-cyclodextrin polymer

• Francesco Trotta,
• Fabrizio Caldera,
• Roberta Cavalli,
• Andrea Mele,
• Carlo Punta,
• Lucio Melone,
• Franca Castiglione,
• Barbara Rossi,
• Monica Ferro,
• Vincenza Crupi,
• Domenico Majolino,
• Valentina Venuti and
• Dominique Scalarone

Beilstein J. Org. Chem. 2014, 10, 2586–2593, doi:10.3762/bjoc.10.271

• collected in backscattering geometry in the wavenumber range of 100–3500 cm−1, by using an exciting radiation at 632.8 nm (He−Ne laser, power at the output ≈20 mW). The laser was focused onto the sample surface with a spot size of about 1 μm2 through the 80× objective (NA = 0.9) of a microprobe setup

• (Horiba-Jobin-Yvon LabRam HR800) consisting of a 80 cm focal length spectrograph using a 1800 grooves/mm grating and a charge-coupled device (CCD) detector cryogenically cooled by liquid nitrogen. The elastically scattered radiation was filtered by using a notch filter. In this configuration, the

Selenium halide-induced bridge formation in [2.2]paracyclophanes

• Laura G. Sarbu,
• Henning Hopf,
• Peter G. Jones and
• Lucian M. Birsa

Beilstein J. Org. Chem. 2014, 10, 2550–2555, doi:10.3762/bjoc.10.266

• Diffraction Xcalibur E diffractometer using monochromated Mo Kα radiation (λ = 0.71073 Å). Crystal data: C22H20Cl2, monoclinic, P21/c, a = 9.0685(3), b = 8.0240(3), c = 23.1441(8) Å, β = 93.423(3)° (at 100 K), Z = 4. Structure refinement: The structure was treated as a non-merohedral twin (by 180° rotation

Loose-fit polypseudorotaxanes constructed from γ-CDs and PHEMA-PPG-PEG-PPG-PHEMA

• Tao Kong,
• Lin Ye,
• Ai-ying Zhang and
• Zeng-guo Feng

Beilstein J. Org. Chem. 2014, 10, 2461–2469, doi:10.3762/bjoc.10.257

• . The radiation source was Ni-filtered, Cu Kα radiation with a wavelength of 0.154 nm. The voltage was set to 40 kV and the current to 40 mA. Samples were placed on a sample holder and scanned from 2θ = 4.5 to 60 ° at a speed of 5 ° min−1. Materials γ-CD (Wako, Japan) and PPO-PEO-PPO (comprised of a

Oxidative phenylamination of 5-substituted 1-hydroxynaphthalenes to N-phenyl-1,4-naphthoquinone monoimines by air and light “on water”

• Julio Benites,
• Juan Meléndez,
• Cynthia Estela,
• David Ríos,
• Luis Espinoza,
• Iván Brito and
• Jaime A. Valderrama

Beilstein J. Org. Chem. 2014, 10, 2448–2452, doi:10.3762/bjoc.10.255

• by on-water oxidative phenylamination of 1,5-dihydroxynaphthalene (1) and 5-acetylamino-1-hydroxynaphthalene (5) with oxygen-substituted phenylamines under aerobic conditions and either solar or green LED radiation, in the presence of rose bengal as singlet oxygen sensitizer. As compared to the

• radiation; Introduction The growing demand for the application of environmentally friendly technologies has led, in the last decades, to a great deal of research effort to develop low-impact alternative synthetic methods as well as to replace toxic and harmful solvents by more environmentally benign ones

• green route for the preparation of N-phenyl-1,4-naphthoquinone monoimines by on-water oxidative coupling reaction of 1-hydroxynaphthalene derivatives with oxygen-substituted phenylamines under solar light or green LEDs radiation, rose bengal as singlet oxygen sensitizer and aerobic conditions. Results

Molecular ordering at electrified interfaces: Template and potential effects

• Thanh Hai Phan and
• Klaus Wandelt

Beilstein J. Org. Chem. 2014, 10, 2243–2254, doi:10.3762/bjoc.10.233

• dicationic character of the DBV2+ building blocks of this cavitand structure was verified by ex situ XPS measurements using synchrotron radiation, namely by a dominant N(1s) signal at 402.1 eV [27]. Sweeping the electrode potential to a value below −200 mV vs RHE causes the disintegration of the cavitand

Photorelease of phosphates: Mild methods for protecting phosphate derivatives

• Sanjeewa N. Senadheera,
• Abraham L. Yousef and
• Richard S. Givens

Beilstein J. Org. Chem. 2014, 10, 2038–2054, doi:10.3762/bjoc.10.212

• intact or rearrange to more strongly absorbing chromophores which compete for the effective radiation wavelengths, often resulting in incomplete conversions that compromise their synthetic utility. These chromophores and especially their photoproducts are also highly fluorescent, which frequently prove

• benzyl (30b–d) moieties, and naphthylacetyl [37] reportedly lowered the singlet and triplet state energies only modestly [10][11] and were unsuitable because these chromophores remained intact and in competition for incident radiation. Photolysis of 1,4-HNA DEP (14a) in 1% aq MeOH released DEP with

• competition for incident radiation by the unrearranged byproduct chromophore 12 or 15. The role of H2O and hydroxylic solvents observed in this series is in complete accord with solvent effects on the parent pHP photoreactions [6][13][15][40][41][42][43][44][45][46]. The photo-Favorskii reaction (Scheme 7) is

A new charge-tagged proline-based organocatalyst for mechanistic studies using electrospray mass spectrometry

• J. Alexander Willms,
• Rita Beel,
• Martin L. Schmidt,
• Christian Mundt and
• Marianne Engeser

Beilstein J. Org. Chem. 2014, 10, 2027–2037, doi:10.3762/bjoc.10.211

• to the reported procedure [54] and obtained as orange oil (using L-proline: 83%, using 1: 80%). Crystal structure determination: X-ray crystallographic analysis of 7 was performed on a Nonius KappaCCD diffractometer using graphite monochromated Mo Kα radiation (λ = 0.71073 Å). Intensities were

Photo, thermal and chemical degradation of riboflavin

• Muhammad Ali Sheraz,
• Sadia Hafeez Kazi,
• Sofia Ahmed,
• Zubair Anwar and
• Iqbal Ahmad

Beilstein J. Org. Chem. 2014, 10, 1999–2012, doi:10.3762/bjoc.10.208

• been identified that affect the stability of RF. These factors include radiation source, its intensity and wavelength, pH, presence of oxygen, buffer concentration and ionic strength, solvent polarity and viscosity, and use of stabilizers and complexing agents. A detailed review of the literature in

• number of factors that are discussed as follows: Radiation source, intensity and wavelengths The emission characteristics of the radiation source are an important factor that plays a significant role in the photodegradation of RF. Around 30% of RF is destroyed by sunlight in milk within only 30 minutes

• aerobic and anaerobic conditions [11][14][15][18][20][21][23][24][25][26][27][28][29][30][31][32][33][34][35][65]. A number of studies have been conducted by employing different low and high intensity radiation sources emitting at different wavelengths in the UV and visible regions for the photolysis of

Molecular recognition of surface-immobilized carbohydrates by a synthetic lectin

• Melanie Rauschenberg,
• Eva-Corrina Fritz,
• Christian Schulz,
• Tobias Kaufmann and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2014, 10, 1354–1364, doi:10.3762/bjoc.10.138

• software Drop Shape Analysis. X-ray photoelectron spectroscopy (XPS): X-ray photoelectron spectra were recorded on a Kratos Axis Ultra system (Kratos Analytical, Manchester/UK). Monochromatized Al Ka radiation (1486.6 eV) as the excitation source and a pass energy of 20 meV for narrow scans were used. The

On the mechanism of photocatalytic reactions with eosin Y

• Michal Majek,
• Fabiana Filace and
• Axel Jacobi von Wangelin

Beilstein J. Org. Chem. 2014, 10, 981–989, doi:10.3762/bjoc.10.97

• radiation events of several recent literature protocols by recording the quantum yields Φ [15][16][17][19][20][21]. Furthermore, we have learned along the way that the reactions appear to be strongly dependent on the pH of the solution and the type of lamp used for irradiation. Here, we present a detailed

• specified in the literature [19][21], the majority of commercial CFLs cover similar spectral ranges with the individual UV edge being significantly below 400 nm and with substantial radiation power in the region of 400–500 nm. A similar wavelength distribution is seen in the spectrum of commercial white

The influence of intraannular templates on the liquid crystallinity of shape-persistent macrocycles

• Joscha Vollmeyer,
• Ute Baumeister and
• Sigurd Höger

Beilstein J. Org. Chem. 2014, 10, 910–920, doi:10.3762/bjoc.10.89

• /min) from the isotropic liquid. 2D patterns were recorded by an area detector HIStar (Siemens/Bruker) using Ni-filtered Cu Kα radiation. The patterns of 1d, the compound without intraannular substitution, show in the isotropic liquid at 160 °C (Figure 5a) the usual outer diffuse scattering at about

Dimerisation, rhodium complex formation and rearrangements of N-heterocyclic carbenes of indazoles

• Zong Guan,
• Jan C. Namyslo,
• Martin H. H. Drafz,
• Martin Nieger and
• Andreas Schmidt

Beilstein J. Org. Chem. 2014, 10, 832–840, doi:10.3762/bjoc.10.79

• state of 298.15 K and 1 mol/dm3 concentration. Crystal structure determinations of 14c, 15e, 16b The single-crystal X-ray diffraction study was carried out on a Bruker-Nonius Kappa-CCD at 123(2) K using MoKα radiation (λ = 0.71073 Å). Direct Methods (SHELXS-97) [30] were used for structure solution and

Unusual polymorphism in new bent-shaped liquid crystals based on biphenyl as a central molecular core

• Anna Kovářová,
• Svatopluk Světlík,
• Václav Kozmík,
• Jiří Svoboda,
• Vladimíra Novotná,
• Damian Pociecha,
• Ewa Gorecka and
• Natalia Podoliak

Beilstein J. Org. Chem. 2014, 10, 794–807, doi:10.3762/bjoc.10.75

• system (CuKα radiation, Vantec 2000 area detector, MRI TCPU H heating stage) working in transmission mode and a Bruker GADDS system (CuKα radiation, Vantec 2000 area detector area detector) working in reflection mode. In both systems the temperature stability was 0.1 K. Powder samples for the Nanostar

Self-assembly of metallosupramolecular rhombi from chiral concave 9,9’-spirobifluorene-derived bis(pyridine) ligands

• Rainer Hovorka,
• Sophie Hytteballe,
• Torsten Piehler,
• Georg Meyer-Eppler,
• Filip Topić,
• Kari Rissanen,
• Marianne Engeser and
• Arne Lützen

Beilstein J. Org. Chem. 2014, 10, 432–441, doi:10.3762/bjoc.10.40

• Dual Source diffractometer equipped with an Atlas detector using mirror monochromated Mo Ka radiation (λ = 0.71073 Å). CrysAlisPro software [39] was used for data measurement and processing as well as to apply the numerical absorption correction. The structures were solved by direct methods (SIR97 [40

Intermediates in monensin biosynthesis: A late step in biosynthesis of the polyether ionophore monensin is crucial for the integrity of cation binding

• Wolfgang Hüttel,
• Jonathan B. Spencer and
• Peter F. Leadlay

Beilstein J. Org. Chem. 2014, 10, 361–368, doi:10.3762/bjoc.10.34

• (10) Å, b = 21.0283(3) Å, c = 21.1481(3) Å, V = 3718.56(9) Å3, Z = 4, ρcalcd = 1.1277 Mg m−3, space group P212121, Mo Kα radiation (λ = 0.71073 Å), μ(MoKα) = 0.105 mm−1, F(000) = 1552. Sodium dehydroxy-monensin A (5) crystallised from ethyl acetate/hexane as colourless needles, C36H61NaO10 (Mr

• = 676.85), empirical formula: C36H64NaO10·1.5H2O (Mr = 703.87, solvent estimated), crystal size 0.46 × 0.42 × 0.35 mm3, orthorhombic, a = 8.04150(10) Å, b = 21.3058(3) Å, c = 24.1816(3) Å, V = 4143.05(9) Å3, Z = 4, ρcalcd = 1.128 Mg m−3, space group P212121, Mo Kα radiation (λ = 0.71073 Å), μ(MoKα) = 0.091

Cyclic phosphonium ionic liquids

• Sharon I. Lall-Ramnarine,
• Joshua A. Mukhlall,
• James F. Wishart,
• Robert R. Engel,
• Alicia R. Romeo,
• Masao Gohdo,
• Sharon Ramati,
• Marc Berman and
• Sophia N. Suarez

Beilstein J. Org. Chem. 2014, 10, 271–275, doi:10.3762/bjoc.10.22

• would be exposed to extreme conditions, such as environmental exposure to high temperatures or exposure to extreme electromagnetic radiation (as in a dye-sensitized solar cell or ionizing radiation as in the recycling of spent nuclear fuel). ILs can play important roles in both of these latter areas [16

• ]. While dialkylimidazolium ILs can be efficient extraction media for nuclear separations [17][18][19], the imidazolium cation is also a good acceptor of radiolytically produced excess electrons. The resultant radical participates in radiation damage mechanisms that alter the IL's properties [20]. On the

• other classes of ILs bearing benzyl groups [32]. This family of cations may have the useful attributes for reducing radiation-induced damage of the IL owing to the stabilization of excess charges on the phenyl groups. Conclusion We have successfully prepared a series of new cyclic phosphonium ILs that

The regioselective synthesis of spirooxindolo pyrrolidines and pyrrolizidines via three-component reactions of acrylamides and aroylacrylic acids with isatins and α-amino acids

• Tatyana L. Pavlovskaya,
• Fedor G. Yaremenko,
• Victoria V. Lipson,
• Svetlana V. Shishkina,
• Oleg V. Shishkin,
• Vladimir I. Musatov and
• Alexander S. Karpenko

Beilstein J. Org. Chem. 2014, 10, 117–126, doi:10.3762/bjoc.10.8

• /сm3, μ(Mo Kα) = 3.040 mm−1, F(000) = 328. Intensities of 6411 reflections (3942 independent, Rint = 0.018) were measured on an «Xcalibur-3» diffractometer (graphite monochromated Mo Kα radiation, CCD detector, ω-scaning, 2Θmax = 60°). The colourless crystals of 6a (C21H19N2O5BrCl2) are triclinic. At

• «Xcalibur-3» diffractometer (graphite monochromated Mo Kα radiation, CCD detector, ω-scaning, 2Θmax = 50°). The structures were solved by direct methods using the SHELXTL package [43]. The absorption correction was performed using the multi-scan method (Tmin = 0.582, Tmax = 0.751 for 4a and Tmin = 0.563

Less reactive dipoles of diazodicarbonyl compounds in reaction with cycloaliphatic thioketones – First evidence for the 1,3-oxathiole–thiocarbonyl ylide interconversion

• Valerij A. Nikolaev,
• Alexey V. Ivanov,
• Ludmila L. Rodina and
• Grzegorz Mlostoń

Beilstein J. Org. Chem. 2013, 9, 2751–2761, doi:10.3762/bjoc.9.309

• for column chromatography. Reaction monitoring and Rf measurements were performed at Silufol UV-254 (Kavalier, ČSSR) plates. Single crystal X-ray data were collected with a Bruker SMART CCD diffractometer (MoKα radiation, λ = 0.71073 Å, graphite monochromator). Diazodicarbonyl compounds 2a–c were

• a Nonius KappaCCD area-detector diffractometer [28] by using graphite-monochromated Mo Kα radiation (λ 0.71073 Å) and an Oxford Cryosystems Cryostream 700 cooler. The view of the molecule is shown in Figure 2. Data reduction was performed with HKL Denzo and Scalepack [29]. The intensities were

Advancements in the mechanistic understanding of the copper-catalyzed azide–alkyne cycloaddition

• Regina Berg and
• Bernd F. Straub

Beilstein J. Org. Chem. 2013, 9, 2715–2750, doi:10.3762/bjoc.9.308

• ) than with the standard catalyst systems, i.e. copper(II) salts plus reducing agent or copper(I) salts [14]. This method can be significantly sped up by applying microwave radiation [43]. It is also beneficial to add copper(II) sulfate, but this is usually not mandatory as the patina on the copper

Silica sulfuric acid: a reusable solid catalyst for one pot synthesis of densely substituted pyrrole-fused isocoumarins under solvent-free conditions

• Sudipta Pathak,
• Kamalesh Debnath and
• Animesh Pramanik

Beilstein J. Org. Chem. 2013, 9, 2344–2353, doi:10.3762/bjoc.9.269

• were collected with Mo Kα radiation at 296 K using the Bruker APEX-II CCD System. The crystals were positioned at 50 mm from the CCD. Frames were measured with a counting time of 5 s. Data analyses were carried out with the Bruker APEX2 and Bruker SAINT program. The structures were solved using direct

Synthesis and characterization of novel bioactive 1,2,4-oxadiazole natural product analogs bearing the N-phenylmaleimide and N-phenylsuccinimide moieties

• Catalin V. Maftei,
• Elena Fodor,
• Peter G. Jones,
• M. Heiko Franz,
• Gerhard Kelter,
• Heiner Fiebig and
• Ion Neda

Beilstein J. Org. Chem. 2013, 9, 2202–2215, doi:10.3762/bjoc.9.259

• ), 827 (s), 771 (m), 737 (w), 700 (s), 686 (m), 652 (w), 624 (w) cm−1. X-ray structure determinations Data are summarized in Table 2. Intensities were determined at 100 K on Oxford Diffraction diffractometers by using monochromated Mo Kα or mirror-focussed Cu Kα radiation. Structures were refined on F2

Structure of 1,5-benzodiazepinones in the solid state and in solution: Effect of the fluorination in the six-membered ring

• Marta Pérez-Torralba,
• Rosa M. Claramunt,
• M. Ángeles García,
• Concepción López,
• M. Carmen Torralba,
• M. Rosario Torres,
• Ibon Alkorta and
• José Elguero

Beilstein J. Org. Chem. 2013, 9, 2156–2167, doi:10.3762/bjoc.9.253

• , 3.15; N, 10.76. X-ray data collection and structure refinement. Data collection for all compounds was carried out at room temperature on a Bruker Smart CCD diffractometer using graphite-monochromated Mo Kα radiation (λ = 0.71073 Å) operating at 50 kV and 30 mA for 1 and 2. In all cases, data were

Temperature measurements with two different IR sensors in a continuous-flow microwave heated system

• Jonas Rydfjord,
• Fredrik Svensson,
• Magnus Fagrell,
• Jonas Sävmarker,
• Måns Thulin and
• Mats Larhed

Beilstein J. Org. Chem. 2013, 9, 2079–2087, doi:10.3762/bjoc.9.244

• popular in organic and medicinal chemistry [4][5][6], mostly owing to the development of computer-controlled dedicated reactors [7][8][9][10] that allow safe and rapid heating to high temperatures and elevated pressures. Microwave radiation directly heats the reaction mixture through two mechanisms

• than the walls [8]. Unfortunately, under microwave radiation the usual methods to directly measure the internal liquid temperature of a reaction mixture such as thermocouples or mercury thermometers are affected by the electromagnetic field and will thus not be possible to use in the radiated zone [14

Integrating reaction and analysis: investigation of higher-order reactions by cryogenic trapping

• Skrollan Stockinger and
• Oliver Trapp

Beilstein J. Org. Chem. 2013, 9, 1837–1842, doi:10.3762/bjoc.9.214

• ][26], an oxidizing agent [27] or by physical decomposition by radiation [28] or heating [29][30][31] of a precursor system. Here, we used benzenediazonium-2-carboxylate as a benzyne precursor, which thermally decomposes by elimination of nitrogen and carbon dioxide. Results and Discussion Initially

Self-assembly of 2,3-dihydroxycholestane steroids into supramolecular organogels as a soft template for the in-situ generation of silicate nanomaterials

• Valeria C. Edelsztein,
• Andrea S. Mac Cormack,
• Matías Ciarlantini and
• Pablo H. Di Chenna

Beilstein J. Org. Chem. 2013, 9, 1826–1836, doi:10.3762/bjoc.9.213

• diffraction measurements: Diffraction patterns were obtained by using a Siemens D5000 diffractometer with Cu Kα radiation (λ = 1.54056 Å), the stepsize was 0.025° with a measurement time of 6 s per step. Scanning electron microscopy: SEM measurements were performed in a similar manner as described in [25