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41.
One‐Pot Cannizzaro Cascade Synthesis of ortho‐Fused Cycloocta‐2,5‐dien‐1‐ones from 2‐Bromo(hetero)aryl Aldehydes
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Dr. Laurence Burroughs Lee Eccleshare John Ritchie Omkar Kulkarni Prof. Dr. Barry Lygo Prof. Dr. Simon Woodward Dr. William Lewis 《Angewandte Chemie (International ed. in English)》2015,54(36):10648-10651
An intramolecular Cannizzaro‐type hydride transfer to an in situ prepared allene enables the synthesis of ortho‐fused 4‐substituted cycloocta‐2,5‐dien‐1‐ones with unprecedented technical ease for an eight‐ring carboannulation. Various derivatives could be obtained from commercially available (hetero)aryl aldehydes, trimethylsilylacetylene, and simple propargyl chlorides in good yields. 相似文献
42.
J. W. Chalmers S. W. Hodson K. -H. A. Winkler P. R. Woodward N. J. Zabusky 《Fluid Dynamics Research》1988,3(1-4):392-394
We present high resolution simulations with the PPM code of shock-bubble interactions coresponding to the recent Haas-Sturtevant experiments. VCR cinemas show and diagnostic interpretations quantify the variety of shock-vortex interactions 相似文献
43.
Cover Picture: Electron–Proton Decoupling in Excited‐State Hydrogen Atom Transfer in the Gas Phase (Angew. Chem. Int. Ed. 50/2015)
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44.
Mulholland AR Woodward CP Langford SJ 《Chemical communications (Cambridge, England)》2011,47(5):1494-1496
An olefination approach to the construction of covalently linked cyclic metalloporphyrin trimers is presented using fullerenes such as C(60) or C(70) as a template. Yields of the trimer approach 60%. In the absence of a template, the major product is the cyclic dimer (50% yield) with only a small amount of trimer (<10%) formed, indicating this is a template-directed approach. 相似文献
45.
James F. Woodward 《Foundations of Physics Letters》1996,9(1):1-23
Theoretical consequences of the gravitational origin of inertial reaction forces, that is, Mach's principle, are explored. It is argued that Mach's principle leads to the conclusion that time, as we normally treat it in our common experience and physical theory, is not a part of fundamental reality; the past and future have a real, objective existence, as is already suggested by both special and general relativity theory. A laboratory scale experiment whereby Mach's principle, and thus radical timeless ness, can be established is mentioned. 相似文献
46.
Grace-Davidson silica pellets (SMR-057-015) are found to be optimal for surface grafting of (RO)3Si(CH2)3FG reagents. While loadings of up to 2.1 mmol g−1 can be attained (ca. 0.05 mmol per pellet) access of further reagents to the graft sites is problematic above loadings of 0.8 mmol g−1. 13C CPMAS NMR studies may be carried out on individual pellets (using natural abundance substrates) and the resulting spectra are diagnostic in identifying successful subsequent coupling reactions. 相似文献
47.
Crystals of poly-trans-1,4-butadiene of uniform size have been grown from three solvents (n-heptane, methyl isobutyl ketone, and toluene) by using a minimum dissolution temeprature technique. The percentage of double bonds available for reaction in the crystals was determined by epoxidation in suspension; crystal thicknesses were measured by electron microscopy. These values were used to calculate the number of monomer units per fold. The number of available double bonds was found to increase with decreasing molecular weight, evidence for the presence of non-reentrant chains (cilia) at the crystal surfaces. The nature of the chain fold in poly-trans-1,4-butadiene crystals is discussed. 相似文献
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The rangefinder described here is a self-contained instrument for hand-held operation by a diver for searching, tracking, navigation and surveying applications. It has four modes: 1 — to measure range to a passive target directly to ± 1 m; 2 — to measure range to a passive target indirectly to ± 0.1 m; 3 — to measure range to a coded transponder to either ± 1 m or ± 0.1 m; 4 — to indicate the presence of multiple targets downrange where each target occurs in a selected range interval. The pulse echo principle is employed, with pulses typically 250 μs long. The carrier frequency of 300 kHz can be altered easily if required by changing the transducer array. 相似文献