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Anti-markovnikov N-H and O-H additions to electron-deficient olefins catalyzed by well-defined Cu(I) anilido, ethoxide, and phenoxide systems 总被引:1,自引:0,他引:1
The monomeric Cu(I) complexes (IPr)Cu(Z) (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, Z = NHPh, OEt, or OPh) react with YH (Y = PhNH, PhCH2NH, EtO, or PhO) to catalytically add Y-H bonds across the C=C bond of electron-deficient olefins to yield anti-Markovnikov organic products. Catalytic activity has been observed for olefins CH2C(H)(X) with X = CN, C(O)Me, or CO2Me as well as crotononitrile. Preliminary studies implicate an intermediate in which the C-Y bond forms through a nucleophilic addition pathway. 相似文献
3.
J. S. Vincent A. H. Dougan D. L. Lyster J. W. Blue 《Journal of Radioanalytical and Nuclear Chemistry》1981,65(1-2):17-29
A facility for the continuous production of iodine-123 by spallation of elemental caesium by 482 MeV protons has been in operation
at a TRIUMF beam dump for about 2 years. Radioxenon from the target is efficiently trapped on alumina which is subsequently
used to remove the121Te decay product. The yield is 100 mCi/h from a 20 gm/cm2 target at 10 μA. Impurities are125I<2% and121Te<0.2% at 27 hours after end of production. The123I consists mainly of iodide along with significant iodate impurity. The product is used extensively in Canadian clinics for
thyroid analyses and for labelling radiopharmaceuticals. 相似文献
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M.D. Blue 《Radiation measurements》1996,26(6):807-815
Possible causes of degradation of electro-optic systems operating in a space environment include not only the effects of radiation but also the effects of temperature, temperature cycling, atomic oxygen effects (for low-Earth orbits), micrometeoroid impacts, and contamination effects. For the majority of electro-optic components, the radiation environment in space does not present a significant problem. For a few components, or for electro-optic systems that must operate in a high radiation environment, special precautions must be observed. The effects of radiation, as well as other problems of the space environment, on electro-optic components, including recent results from the LDEF satellite experiments and some later measurements, are reviewed. Guidelines for materials and component selection shielding are presented. 相似文献
6.
D.J. Morrissey W. Benenson E. Kashy B. Sherrill A.D. Panagiotou R.A. Blue R.M. Ronningen J. van der Plicht H. Utsunomiya 《Physics letters. [Part B]》1984,148(6):423-427
An effective temperature inferred from the slope of kinetic energy spectra of the emitted fragments is not reflected in the relative populations of excited states of the emitted nuclei. We found that the excited state populations of 6Li, 7Li and 7Be emitted near 90° in the lab from the reaction of 490 MeV 14N with Ag are significantly lower than those expected on the basis of their effective temperature. 相似文献
7.
V. J. Sodd K. L. Scholz J. W. Blue 《Journal of Radioanalytical and Nuclear Chemistry》1982,68(1-2):277-280
A procedure is described for the liquid extraction of ingrown201Tl from its precursor201Pb using N-benzylaniline. The yield for a double extraction averaged 95.9±3.2% for thallium; 2.9±4.2% for lead. Yields for
back extraction into acetic acid averaged 93.7±1.5%. 相似文献
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Munro-Leighton C Delp SA Alsop NM Blue ED Gunnoe TB 《Chemical communications (Cambridge, England)》2008,(1):111-113
Monomeric Cu(I) amido and thiolate complexes that are supported by the N-heterocyclic carbene ligand 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) catalyze the hydroamination and hydrothiolation of electron-deficient vinylarenes with reactivity patterns that are consistent with an intermolecular nucleophilic addition of the amido/thiolate ligand of (IPr)Cu(XR) (X = NH or S; R = Ph, CH2Ph) to free vinylarene. 相似文献
10.
K. Yirak J.M. Foster P. Hartigan B.H. Wilde M.R. Douglas R. Paguio B.E. Blue D. Martinez D. Farley P.A. Rosen A. Frank 《High Energy Density Physics》2013,9(2):251-257
Recent time-series observations of shock waves in stellar jets taken with the Hubble Space Telescope reveal localized bright knots that persist over nearly 15 years. While some of these features represent shock fronts caused by variable velocities in the flow, others appear at the intersection points between distinct bow shocks. Theoretically, when the angle between two intersecting shocks exceeds a certain critical value, a third shock (Mach stem) should form. Because Mach stems form perpendicular to the direction of flow, incoming particles encounter a normal shock instead of an oblique one, which results in brighter emission at this location. To study this phenomenon in a controlled laboratory setting, we have carried out experiments on the Omega laser aimed at understanding the formation, growth, and destruction of Mach stems in the warm dense plasma regime. Our experimental results indicate how the growth rate depends upon included angle, and numerical simulations indicate that it may be possible to stabilize an already-formed Mach stem below the critical angle when certain conditions are satisfied. 相似文献