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1.
Functionalised hydroxylamine derivatives of (S)-prolinol prepared by a Cope elimination have been found to undergo oxidation to the nitrone either in the presence of air or a catalytic quantity of TPAP. These undergo intramolecular cycloaddition to give tricyclic isoxazolidines with high diastereoselectivity. 相似文献
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C. O'Neil P. Galarneau M. -M. Denariez-Roberge 《Applied physics. B, Lasers and optics》1989,49(4):327-330
Degenerated four-wave mixing (DFWM) was realised in five commercial semiconductor-doped glasses (Corning CS3–66, CS3–67, CS3–68, CS3–69, CS3–70). The reflectivity obtained for each glass seems very dependent on the energy excess (E=hv–E
g) and relatively independant on l, the product of the absorption coefficient () by the sample thickness (l). The decay time of the DFWM signal was measured for each glass. The relaxation was found to be different when the photon energy is under or over the gap. 相似文献
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Hydroxylamine derivatives of (S)-prolinol have been generated using a Cope elimination. These undergo reverse-Cope elimination onto a pendant double bond to give morpholine N-oxides containing three contiguous chiral centres. 相似文献
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Björn C.G. Söderberg Jeremiah W. Hubbard Stacey R. Rector Shannon N. O'Neil 《Tetrahedron》2005,61(15):3637-3649
A route to 3,4-fused indoles via two consecutive palladium-catalyzed reactions; an intramolecular Heck reaction followed by a reductive N-heteroannulation is described. Using this route, a number of indoles have been prepared having a variety of ring sizes anchored to the 3- and 4-position of the indole nucleus. Furthermore, a number of functional groups, both carbon and heteroatom substituents can be introduced in (and on) the additional ring without any detrimental effects on the two reactions. 相似文献
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Joosten R Powell J Guo FQ Haustein PE Larimer R McMahan MA Norman EB O'Neil JP Rowe MW VanBrocklin HF Wutte D Xu XJ Cerny J 《Physical review letters》2000,84(22):5066-5069
A light-element radioactive ion-beam capability has been developed at the LBNL 88-Inch Cyclotron. The system is based on the coupled-cyclotrons method and utilizes short-lived species, e.g., 11C, 14O, 13N produced by (p,n) and (p,alpha) reactions at the LBNL Biomedical Isotope Facility Cyclotron. In a first experiment, 197Au(11C,xn)208-xAt excitation functions have been measured for energies ranging from the Coulomb barrier up to 110 MeV using a beam of 11C with intensities up to (1-2)x10(8) ions/sec on target. The results of this experiment are compared to measurements of 197Au(12C, xn)209-xAt excitation functions. 相似文献