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101.
H Ohno M Anzai A Toda S Ohishi N Fujii T Tanaka Y Takemoto T Ibuka 《The Journal of organic chemistry》2001,66(14):4904-4914
Whereas palladium-catalyzed reaction of N-arylsulfonyl-alpha-amino allenes with an aryl iodide (4 equiv) in the presence of potassium carbonate (4 equiv) in DMF at around 70 degrees C affords the corresponding 3-pyrroline derivatives, the reaction in refluxing 1,4-dioxane under otherwise identical conditions yields exclusively or most predominantly the corresponding 2-alkenylaziridines bearing an aryl group on the double bond. Similarly, N-arylsulfonyl-beta-amino allenes can be also cyclized into the corresponding alkenylazetidines bearing a 2,4-cis-configuration under palladium-catalyzed cyclization conditions in DMF. 相似文献
102.
We discuss basic statistical properties of systems with multifractal structure. This is possible by extending the notion of the usual Gibbs-Shannon entropy into more general framework—Rényi’s information entropy. We address the renormalization issue for Rényi’s entropy on (multi)fractal sets and consequently show how Rényi’s parameter is connected with multifractal singularity spectrum. The maximal entropy approach then provides a passage between Rényi’s information entropy and thermodynamics of multifractals. Important issues such as Rényi’s entropy versus Tsallis-Havrda-Charvat entropy and PDF reconstruction theorem are also studied. Finally, some further speculations on a possible relevance of our approach to cosmology are discussed. 相似文献
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104.
Asai S. Azuelos G. Buttar C. Cavasinni V. Costanzo D. Cranmer K. Harper R. Jakobs K. Kanzaki J. Klute M. Mazini R. Mellado B. Quayle W. Richter-Ws E. Takemoto T. Vivarelli I. Wu Sau Lan 《The European Physical Journal C - Particles and Fields》2003,32(2):s19-s54
The European Physical Journal C - The potential for the discovery of a Standard Model Higgs boson in the mass range m H < 2 m Z in the vector boson fusion mode has been studied for the ATLAS... 相似文献
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107.
Yoshinori Shiobara Tomoko Iwata Mitsuaki Kodama Yoshinori Asakawa Tsunematsu Takemoto Yoshimasa Fukazawa 《Tetrahedron letters》1985,26(7):913-916
Dehydrocurdione, a sesquiterpene isolated from , was converted to curcumenol, isocurcumenol or new spirolactones in a highly selective manner and their absolute configurations were determined. 相似文献
108.
Akira Mori Kanji Kubo Manabu Takemoto Hayato Kitaura Seiji Ujiie 《Liquid crystals》2006,33(5):521-530
Two types of symmetric dimers with 5-(4-alkoxybenzoyloxy)tropone cores or with 4-(4-alkoxybenzoyloxy)phenyl cores were synthesized to evaluate the effect of the core structure and the length of the spacer on the mesomorphic properties. The former had smectic C phases whereas the latter had smectic C and F phases. Both types of dimer showed a remarkable odd-even effect on varying the spacer on the mesomorphic properties. Comparison of the thermal stability between them demonstrated that benzenoid twins are more stable than troponoid ones. The layer spacings of the smectic C phases were measured to determine the tilt angles of the core part, the spacer, and the side chains on changing the length of the spacer and the side chains. Troponoid dimers had a larger tilt angle of the core part of the smectic C phase than benzenoid twins, which lowered the thermal stability of the troponoid. Entropy changes of the smectic C phase to the isotropic liquid showed a contrast between troponoids and benzenoids. The former had smaller values and odd-even effects than the latter, which indicated that the former troponoids had a limited number of conformers in mesophases. 相似文献
109.
Ahmed E. Allam Alaa M. Nafady Toshinori Nakagawa Naomichi Takemoto 《Natural product research》2018,32(16):1920-1925
Two new flavonoid glycosides, kaempferol 3-O-α-L-rhamnopyranosyl (1→6) (3′′-acetyl)-β-D-galactopyranoside 1 and kaempferol 3-O-α-L-arabinopyranosyl-5-O-α-L-rhamnopyranoside 2, along with six known ones 3–8 were isolated from the flowers of Vicia faba L. (Fabaceae). Methanol extract and the isolated compounds were tested against lipase and melanogenesis inhibition activities and resulted in that compound 2 showed 53 and 77% lipase inhibition activity in concentrations of 400 and 800 μg/mL, respectively. For melanogenesis, compounds 2, 3 and 4 exhibited potent melanogenesis inhibition activity where the melanin content in melanoma cells was decreased to be about 57.5, 56 and 61%, respectively, with no obvious melanocytotoxicity. The rest of compounds showed weak to moderate activity. The results of melanogenesis inhibition activity of this study suggested the potential use of Vicia faba flowers as a skin-whitening agent and reveal the flowers to be a rich source of important phytochemicals with antilipase and melanogenesis inhibitory activity. 相似文献
110.
Treatment of a mixture of alkyl aldehydes (1) with acid chlorides (2) in the presence of zinc metal powder and a catalytic amount of chlorotrimethylsilane (TMSCl) in dichloromethane brought about highly facile and effective coupling to give selectively the corresponding α-haloacylation and gem-bisacylation products, α-haloalkyl carboxylates and 1,1-dicarboxylates (acylals), in good to excellent yields. 相似文献