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排序方式: 共有344条查询结果,搜索用时 15 毫秒
71.
72.
J. Nokami T. Mandai Y. Imakura K. Nishiuchi M. Kawada S. Wakabayashi 《Tetrahedron letters》1981,22(45):4489-4490
The reaction of phenylsulfinylacetonitrile 1 with ketones or aldehydes gave 4-hydroxy-2-alkenenitriles which were converted to 2- and/or 3-substituted furans by the treatment with diisobutylaluminumhydride(DIBAL) followed by acid hydrolysis. 相似文献
73.
Triethylborane-induced intramolecular 1,4-aryl migration from tin to a carbon-centered radical is described. Treatment of 3-iodoalkyldimethylphenylstannanes with Et(3)B in benzene at reflux followed by an addition of MeMgI provides 3-phenylalkyltrimethylstannanes in good yield via a radical atom-transfer process. 相似文献
74.
Organometallic polymers containing tricarbonyl(η4-diene)-ruthenium(0) and -iron(0) as pendant groups
Hajime Yasuda Yoshitsugu Morita Ippei Noda Kyoko Sugi Akira Nakamura 《Journal of organometallic chemistry》1981,205(2):C9-C13
Vinyl ethers containing tricarbonyl(14-η4-1,3-pentadiene)-ruthenium(0) and -iron(0) species were prepared utilizing selective dienylation with penta-dienylpotassium and were polymerized with cationic initiators to give high molecular weight polymers. The diene-metal moieties were converted into tricarbonyl(13-η3-allyl)metal species by protonation with dry HCl. Tricarbonyl(3-allyl-14-η4-1,3-pentadiene)iron(0) also undergoes cationic polymerization but the presence of its isomer, tricarbonyl(3-propenyl-14-η4-1,3-pentadiene)iron(0) inhibits the polymerization. 相似文献
75.
Suzuki M Watanabe K Fujiwara S Kurasawa T Wakabayashi T Tsuzuki M Iguchi K Yamori T 《Chemical & pharmaceutical bulletin》2003,51(6):724-727
Two norcarotenoids, 1 and 2, related to peridinin (3) were isolated from the cultured dinoflagellate of the genus Symbiodinium, a symbiont of the Okinawan soft coral Clavularia viridis, which contains in abundance antitumor marine prostanoids such as clavulones. The structures of 1 and 2 were elucidated on the basis of spectroscopic analysis. These compounds showed significant growth-inhibitory activity in vitro toward cancer cells. Analysis of fatty acids of the dinoflagellate was also carried out, suggesting that the marine prostanoids are produced by the host soft coral itself. 相似文献
76.
Ishikawa H Sugiyama M Baba I Setaka W Kira M Mikami N 《The journal of physical chemistry. A》2005,109(40):8959-8961
An equilibrium structure of the charge-transfer (CT) state of (p-cyanophenyl)pentamethyldisilane was determined by transient infrared absorption spectroscopy of its CH stretching vibration region, and by the spectral simulation with quantum chemical calculations. It was found that a pattern of the CH stretching vibration bands of the CT state is substantially different from that of the S0 state. This band feature of the CT state was well reproduced assuming the planar sigma(Si-Si)pi* state, where the disilanyl group and the phenyl ring lie in the same plane. Considering that the disilanyl group in the S0 and the locally excited pipi* states lie in the plane perpendicular to the phenyl ring, an occurrence of a twisting-type structural change during the ICT process was experimentally identified in the present study. 相似文献
77.
A high-performance liquid chromatographic determination of idebenone, a new cerebral metabolism-improving agent, in rat serum and brain has been developed. After separation of idebenone on a reversed-phase column, idebenone was reduced once in a platinum catalyst reduction column connected on-line, then monitored quantitatively by electrochemical detection. A linear relationship between the peak-height ratio of idebenone to the internal standard and idebenone concentration was observed in the range 0.015-50 ng with a detection limit of 5 pg (signal-to-noise ratio = 5). This method was satisfactorily rapid and sensitive, and was successfully applied to the determination of idebenone in rat serum and brain tissues. 相似文献
78.
The viscosities of aqueous solutions of Bu
4-n
Ph
n
PBr n=0–4 have been measured over the concentration range 0.01–0.2 M at 15, 25 and 35°C, to examine the differences in ion-water interactions of these quaternary cations. The viscosity data were treated by the extended Jones-Dole equation, including the square term in solute concentration, Dc2. A decrease in the B coefficient with increase in the number of phenyl groups n, and with increasing temperature is observed. Nearly linear dependence of the B coefficient on n was found, in contrast with partial molal volumes for which non-linear relations with n have been found. D decreases with increasing temperature but becomes independent of n at higher temperatures. 相似文献
79.
Masataka Mochizuki Takako Anjo Yuko Wakabayashi Toshie Sone Masashi Okada 《Tetrahedron letters》1980,21(18):1761-1764
N-alkyl-N-(1-hydroperoxyalkyl)nitrosamines were prepared by treatment of the corresponding 1-acetoxyalkyl nitrosamines with hydrogen peroxide in acetic acid through an acid-catalyzed nucleophilic substitution. 相似文献