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The triphenyl phosphite-palladium complex was found to effect catalytic substitution reactions of allylic alcohols via a direct C-O bond cleavage. The dehydrative etherification proceeded efficiently without any cocatalysts and bases to give allylic ethers in good to excellent yields. 相似文献
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A kinetic study on enzymatic S-oxygenation of sulfoxides to sulfones was carried out by a reconstited system with purified cytochrome P-450. A linear correlation observed between log(Vmax)'s and the one-electron oxidation potentials of sulfoxides suggests that the oxygenation of sulfoxides proceeds via one electron transfer process to the active “oxenoid” intermediate of the enzyme. 相似文献
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S. Shinkai M. Ishihara K. Ueda O. Manabe 《Journal of inclusion phenomena and macrocyclic chemistry》1984,2(1-2):111-118
New photoresponsive crown ethers (1H+) having a crown ring and an ammoniumalkyl (H3N+(CH2)n
–, n=4,6,10) group attached to the two sides of an azobenzene have been synthesized. Photoresponsive properties (thermal isomerization, metal extraction, membrane transport, etc.) were examined, and the results were compared with those of other photoresponsive crown ethers and complexons. 相似文献
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Atsuyoshi Ohno Yuji Ishihara Satoshi Ushida Shinzaburo Oka 《Tetrahedron letters》1982,23(31):3185-3188
Benzaldehyde are reduced to benzyl alcohol by a model compound of NAD(P)H almost quantitatively. Reductions of some other aldehydes are also mentioned. 相似文献
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Takimiya K Kunugi Y Konda Y Niihara N Otsubo T 《Journal of the American Chemical Society》2004,126(16):5084-5085
2,6-Diphenylbenzo[1,2-b:4,5-b']dichalcogenophenes including thiophene, selenophene, and tellurophene analogues as organic semiconductors for field-effect transistors were effectively synthesized in three steps from commercially available 1,4-dibromobenzene. All three benzodichalcogenophenes acted as good p-type semiconductors, and particularly the selenophene analogue, 2,6-diphenylbenzo[1,2-b:4,5-b']diselenophene, showed high FET mobility of 0.17 cm2 V-1 s-1. 相似文献
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Koketsu M Choi SY Ishihara H Lim BO Kim H Kim SY 《Chemical & pharmaceutical bulletin》2002,50(12):1594-1596
This study reports depigmenting potency of 1,3-selenazol-4-one derivatives, which would be based upon the finding of direct inhibition to mushroom tyrosinase. 1,3-Selenazol-4-one derivatives exhibited inhibitory effect on dopa oxidase activity of mushroom tyrosinase. In this study, inhibitory effects of six kinds of 1,3-selenazol-4-one derivatives (A, B, C, D, E and F) on mushroom tyrosinase were investigated. Compounds at a concentration of 500 microM exhibited 33.4-62.1% of inhibition on dopa oxidase activity of mushroom tyrosinase. Their inhibitory effects were higher than that of kojic acid (31.7%), a well known tyrosinase inhibitor. 2-(4-Methylphenyl)-1,3-selenazol-4-one (A) exhibited the strongest inhibitory effect among them dose-dependently and in competitive inhibition manner. 相似文献