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41.
Phipps RJ McMurray L Ritter S Duong HA Gaunt MJ 《Journal of the American Chemical Society》2012,134(26):10773-10776
Alkenes and arenes represent two classes of feedstock compounds whose union has fundamental importance to synthetic organic chemistry. We report a new approach to alkene arylation using diaryliodonium salts and Cu catalysis. Using a range of simple alkenes, we have shown that the product outcomes differ significantly from those commonly obtained by the Heck reaction. We have used these insights to develop a number of new tandem and cascade reactions that transform readily available alkenes into complex arylated products that may have broad applications in chemical synthesis. 相似文献
42.
Bernhard Pemmer Jochen G. Hofstaetter Florian Meirer Stephan Smolek Peter Wobrauschek Rolf Simon Robyn K. Fuchs Matthew R. Allen Keith W. Condon Susan Reinwald Roger J. Phipps David B. Burr Eleftherios P. Paschalis Klaus Klaushofer Christina Streli Paul Roschger 《Journal of synchrotron radiation》2011,18(6):835-841
Based on clinical trials showing the efficacy to reduce vertebral and non‐vertebral fractures, strontium ranelate (SrR) has been approved in several countries for the treatment of postmenopausal osteoporosis. Hence, it is of special clinical interest to elucidate how the Sr uptake is influenced by dietary Ca deficiency as well as by the formula of Sr administration, SrR versus strontium chloride (SrCl2). Three‐month‐old ovariectomized rats were treated for 90 days with doses of 25 mg kg?1 d?1 and 150 mg kg?1 d?1 of SrR or SrCl2 at low (0.1% Ca) or normal (1.19% Ca) Ca diet. Vertebral bone tissue was analysed by confocal synchrotron‐radiation‐induced micro X‐ray fluorescence and by backscattered electron imaging. Principal component analysis and k‐means clustering of the acquired elemental maps of Ca and Sr revealed that the newly formed bone exhibited the highest Sr fractions and that low Ca diet increased the Sr uptake by a factor of three to four. Furthermore, Sr uptake in bone of the SrCl2‐treated animals was generally lower compared with SrR. The study clearly shows that inadequate nutritional calcium intake significantly increases uptake of Sr in serum as well as in trabecular bone matrix. This indicates that nutritional calcium intake as well as serum Ca levels are important regulators of any Sr treatment. 相似文献
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Taylor Chin Ashley Phipps Frank R. Fronczek Ralph Isovitsch 《Journal of heterocyclic chemistry》2011,48(1):215-217
A novel triazene, 4‐[(E)‐2‐(4‐cyanophenyl)diazenyl]‐morpholine ( 1 ) was prepared via a diazonium ion coupling reaction between 4‐aminobenzonitrile and morpholine. The x‐ray structure of 1 was determined and evidenced π delocalization in the triazene subunit. The room temperature absorption spectrum of 1 in acetonitrile was dominated by an intense triazene‐centered π→π* transition at 325 nm. Compound 1 was observed to be luminescent, with an emission maximum at 434 nm in room temperature acetonitrile solution. The emission spectrum of 1 in propionitrile glass at 77K exhibited a narrowed emission band with a maximum at 449 nm. Broad emission from 400–700 nm with poorly resolved vibrational structure was observed from solid 1 at room temperature. J. Heterocyclic Chem., 2011. 相似文献
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Paddock VL Phipps RJ Conde-Angulo A Blanco-Martin A Giró-Mañas C Martin LJ White AJ Spivey AC 《The Journal of organic chemistry》2011,76(5):1483-1486
An efficient synthesis of (±)-trans,cis-4-hydroxy-5,6-di-O-isopropylidenecyclohex-2-ene-1-one (3) has been developed from acetonide-protected meso-1,2-dihydrocatechol derivative 1 via photooxygenation, then Kornblum-DeLaMare rearrangement. The product is unstable unless its 4-hydroxy group is protected, as it undergoes facile dimerization in solution to a 1:1 mixture of diastereoisomeric decahydrodibenzofurans 8 and 9. A new synthesis of the dihydrocatechol 1 from 1,3-cyclohexadiene has also been developed. 相似文献
50.
T. E. Phipps Jr. 《Foundations of Physics》1980,10(9-10):811-817
The Ehrenfest paradox is reviewed in order to categorize classes of “resolution” that are logically at least semiconsistent. Cantoni's candidate is analyzed with reference to such a taxonomy of resolutions. 相似文献