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A Visible Light Photocatalytic Cross‐Dehydrogenative Coupling/Dehydrogenation/6π‐Cyclization/Oxidation Cascade: Synthesis of 12‐Nitroindoloisoquinolines from 2‐Aryltetrahydroisoquinolines 下载免费PDF全文
Fabian Rusch Lisa‐Natascha Unkel Dirk Alpers Dr. Frank Hoffmann Prof. Dr. Malte Brasholz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(23):8336-8340
A visible light‐induced photocatalytic dehydrogenation/6π‐cyclization/oxidation cascade converts 1‐(nitromethyl)‐2‐aryl‐1,2,3,4‐tetrahydroisoquinolines into novel 12‐nitro‐substituted tetracyclic indolo[2,1‐a]isoquinoline derivatives. Various photocatalysts promote the reaction in the presence of air and a base, the most efficient being 1‐aminoanthraquinone in combination with K3PO4. Further, the 12‐nitroindoloisoquinoline products can be accessed directly from C1‐unfunctionalized 2‐aryl‐1,2,3,4‐tetrahydroisoquinolines by extending the one‐pot protocol with a foregoing photocatalytic cross‐dehydrogenative coupling reaction, resulting in a quadruple cascade transformation. 相似文献
13.
Ruben Canton‐Vitoria Tobias Scharl Anastasios Stergiou Alejandro Cadranel Raul Arenal Dirk M. Guldi Nikos Tagmatarchis 《Angewandte Chemie (International ed. in English)》2020,59(10):3976-3981
Molybdenum disulfide nanosheets covalently modified with porphyrin were prepared and fully characterized. Neither the porphyrin absorption nor its fluorescence was notably affected by covalent linkage to MoS2. The use of transient absorption spectroscopy showed that a complex ping‐pong energy‐transfer mechanism, namely from the porphyrin to MoS2 and back to the porphyrin, operated. This study reveals the potential of transition‐metal dichalcogenides in photosensitization processes. 相似文献
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Karg M Schelero N Oppel C Gradzielski M Hellweg T von Klitzing R 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(16):4648-4654
A novel, simple, and very efficient method to prepare hydrophobically modified gold particles is presented. Gold nanoparticles of different sizes and polydispersities were prepared. The diameter of the gold particles ranges from 5 to 37 nm. All systems were prepared in aqueous solution stabilized by citrate and afterwards transferred into an organic phase by using amphiphilic alkylamine ligands with different alkyl chain lengths. The chain length was varied between 8 and 18 alkyl groups. Depending on the particle size and the alkylamine, different transfer efficiencies were obtained. In some cases, the phase transfer has a yield of about 100%. After drying, the particles can be redispersed in different organic solvents. Characterization of the particles before and after transfer was performed by using UV/Vis spectroscopy, transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS) techniques. The effect of organic solvents with various refractive indices on the plasmon band position was investigated. 相似文献
16.
Dimitrios V. Stergiou Spyros C. Karkabounas Panayotis G. Veltsistas Nicholaos P. Evmiridis Athanasios G. Vlessidis 《Mikrochimica acta》2007,158(1-2):59-64
A kinetic-potentiometric method is described for the quantitative assay of formaldehyde (HCHO) in pharmaceutical and industrial
preparations. It is based on the reaction of HCHO with (ethylenediamine)-Cu(II)-sulfate [Cu(CH2NH2)2(H2O)2] · SO4. The changes in potential, resulting from the release of the Cu(II) cations, are monitored with a Cu(II)-ion selective electrode.
The calibration curve for the HCHO is linear in the concentration range 50–250 mg L−1, with a limit of detection of 8.5 mg L−1. The method shows very good reproducibility with an RSD of 2.6% for successive injections (n = 5) of 150 mg L−1 HCHO primary solution, while it is interference free. The method was successfully tested in various industrial and pharmaceutical
preparations. 相似文献
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M. Barth E. A. De Wolf P. Theocharopoulos H. Drevermann Y. Goldschmidt-Clermont M. Spyropoulou-Stassinaki R. T. Ross G. Vassiliadis C. Caso R. Contri F. Fontanelli J. F. Baland J. Beaufays F. Grard L. Gatignon A. Stergiou R. T. Van de Walle P. V. Chliappnikov A. B. Fenyuk L. N. Gerdyukov I. A. Gritsaenko T. C. Makharadze V. I. Nikolaenko Y. L. Petrovikh V. M. Ronjin 《Zeitschrift fur Physik C Particles and Fields》1984,22(1):23-31
Inclusive and semi-inclusive cross sections and distributions of γ's and π0's inK + p interactions at 70 GeV/c are presented. The results are compared to other experiments and to the Lund model for low-p T hadron collisions. 相似文献
20.
P.V. Chliapnikov L.N. Gerdyukov O.G. Tchikilev A.P. Vorobjev G. Ciapetti W. Dunwoodie Y. Goldschmidt-Clermont A. Grant Z. Sekera A. Stergiou J. Tuominieni N. Yamdagni J.N. Carney D.C. Colley M. James G.T. Jones D. Sherbatt F. Grard D. Vignaud 《Physics letters. [Part B]》1975,55(2):237-240
The reaction K+p→Δ++(1236) + anything is studied at a beam momentum of 16.0 GeV/c. The total and topological cross sections for K+π? interactions are estimated by a Chew-Low extrapolation from threshold to the c.m. energy of 3.4 GeV by the maximum likelihood method. 相似文献