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991.
992.
Allyl aryl ethers can be easily cleaved by the use of 10% Pd/C under mild and basic conditions. The present reaction would involve a SET process rather than a π-allyl-palladium complex. The scope and limitation of this new deprotective methodology is also described. 相似文献
993.
K Mitani T Yoshida T Suzuki E Koshinaka H Kato Y Ito T Fujita 《Chemical & pharmaceutical bulletin》1988,36(2):776-783
994.
Osamu Iyama 《Advances in Mathematics》2007,210(1):51-82
We study Auslander correspondence from the viewpoint of higher-dimensional analogue of Auslander-Reiten theory [O. Iyama, Higher dimensional Auslander-Reiten theory on maximal orthogonal subcategories, Adv. Math. 210 (1) (2007) 22-50 (this issue)] on maximal orthogonal subcategories. We give homological characterizations of higher dimensional analogue of Auslander algebras in terms of global dimension, Auslander-type conditions and so on. Especially we give an answer to a question of M. Artin [M. Artin, Maximal orders of global dimension and Krull dimension two, Invent. Math. 84 (1) (1986) 195-222]. They are also closely related to Auslander's representation dimension of Artin algebras [M. Auslander, Representation dimension of Artin algebras, in: Lecture Notes, Queen Mary College, London, 1971] and Van den Bergh's non-commutative crepant resolutions of Gorenstein singularities [M. Van den Bergh, Non-commutative crepant resolutions, in: The Legacy of Niels Henrik Abel, Springer, Berlin, 2004, pp. 749-770]. 相似文献
995.
996.
The rate constants for the reaction of NO3· with sulfur compounds in acetonitrile have been determined by the flash photolysis method. The rate constant for dimethyl sulfone (2.7 × 104 M?1s?1 at ?10°C) is larger than that of the deuterium derivative, indicating that NO3· abstracts the hydrogen atom from dimethyl sulfone. In the case of dimethyl sulfide, the rate constant was evaluated to be 1.5 × 109 M?1 s?1 at ?10°C; the transient absorption band attributable to the cation radical was observed after the decay of NO3·, suggesting the electron transfer reaction from the sulfide to NO3·. For diphenyl sulfide and dimethyl disulfide, the electron transfer reactions were also confirmed. For dimethyl sulfoxide, the reaction rate constant of 1.2 × 109 M?1 s?1 (at ?10°C) was not practically affected by the deuterium substitution, suggesting that NO3· adds to sulfur atom forming (CH3)2?(O)-ONO2. On the other hand, for diphenyl sulfoxide, the electron transfer reaction occurs. By the comparison of these rate constants in acetonitrile solution with the reported rate constants in the gas phase, the change of the reaction paths was revealed. 相似文献
997.
K. Asahi H. Okuno H. Ueno H. Sato J. Kura T. Kubo T. Nakamura N. Inabe A. Yoshida Y. Ohkubo M. Adachi T. Ichihara M. Ishihara T. Shimoda H. Miyatake N. Takahashi D. Beaumel D. J. Morrissey W. -D. Schmidt-Ott 《Hyperfine Interactions》1992,75(1-4):101-108
Ejectile nuclei in the fragmentation of intermediate-energy heavy-ion projectiles were found to be largely spin polarized.
The observed polarization as a function of the outgoing momentum was nicely explained by a simple kinematical argument based
on the participant-spectator model of projectile fragmentation. The measurements extended to cover several different targets,
incident energies, exit channels, and emission angles revealed that substantial polarization shows up widely in projectile
fragmentation reactions. Furthermore, this polarization exhibits an interesting behavior which may be interpreted as a manifestation
of a gradual change in the deflection angle from positive to negative values as the energy increases and/or the target-Z decreases. The present polarization results also suggests various applications of spin polarized radioactive beams. As the
first example of such an application, we present a recent result on theg-factor measurements on neutron-rich nuclei. 相似文献
998.
The effects of foreign impurity ions in the conduction plane on the β″-Al2O3 lattice have been analyzed by molecular dynamics. As impurity ions, K and Ca ions were chosen and Na sites in the conduction plane were replaced with these ions. Results are summarized as follows: (1) The β″-Al2O3 lattice expands perpendicular to the conduction plane when K ions are doped; (2) Ca ions do not contribute to expansions of the β″-Al2O3 lattice; (3) both K and Ca ions reduce the mean square displacement of Na ions, which can be attributed to decreased Na ion diffusion. 相似文献
999.
Crotonothioamide, sorbothioamide, and cinnamothioamide undergo a threo selective aldol condensation via their enolates generated by a Michael addition of organometallics. 相似文献
1000.
Yoshinao Tamaru Hirofumi Ochiai Tatsuya Nakamura Kazunori Tsubaki Zen-ichi Yoshida 《Tetrahedron letters》1985,26(45):5559-5562
2-Carboethoxyethylzinc iodide and 3-carboethoxypropylzinc iodide are generated by the reaction of the corresponding iodoesters with Zn-Cu couple and utilized for the palladium catalyzed coupling reaction with acid chloride to quantitatively provide gamma- and delta- keto esters, respectively. 相似文献