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Koiso T Yamamoto K Hata Y Takahashi Y Kita E Ohshima K Okamura FP 《J Phys Condens Matter》1996,8(38):7059-7065
A structural study of [Formula: see text], grown from aqueous solution, was performed using anomalous x-ray scattering near the Cs K absorption edge to determine an absolute configuration of constituent atoms. The sense of the helical structure of the [Formula: see text] chain was found to be predominantly right-handed through a comparison of observed Bragg Bijvoet ratios with calculated ones. Assuming that [Formula: see text] consists of the two domains (i.e. right- and left-handed helices), we estimate that the volume fraction for the right-handed helix is [Formula: see text]. 相似文献
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New pyrrolylalkanethiolate-stabilized gold and palladium nanoparticles have been prepared: electrochemical polymerization of their metal nanoparticles and their TEMPO-derivatized metal nanoparticles gave the remarkably stable poly(pyrrole metal nanoparticle) films on metal electrodes. 相似文献
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Appropriately protected guanosine derivatives were successfully converted to the corresponding O6-substituted guanosine derivatives by treatment with dialkyl- or diaryl-phosphoryl halides, dialkyl- or diaryl-phosphinothioyl halides, arenesulfonyl chlorides, and trialkylsilyl chlorides. 相似文献
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Toshio Takido Sachiko Tamura Kenji Sato Haruo Kamijo Toshikatsu Nakazawa Manabu Seno Tadashi Hata 《Journal of heterocyclic chemistry》1998,35(2):437-443
The synthesis of hexahydrooxoepithiopyridinedicarboxyimide (5: X2 = N-Ph) by the reaction of thioamides 1 with N-substituted maleimide ( 2a ) was examined. The reaction of primary thioamides, such as thiobenzamide and p-toluthioamide with N-phenylmaleimide gives compounds 5 together with corresponding 4-hydroxy-1,3-thiazoles 4 . However, a similar reaction of secondary thioamides, such as N-methylthioacetamide, thiobenzanilide, with N-phenylmaleimide did not provide compounds 5 without addition of acid. The reaction pathway and the configuration of 5 were also investigated. 相似文献
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Nambu H Hata K Matsugi M Kita Y 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(2):719-727
The combination of the water-soluble radical initiator, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (VA-044) and the surfactant, cetyltrimethyl-ammonium bromide (CTAB), was found to be the most suitable condition for the effective and direct synthesis of useful active thioesters (pentafluorophenyl thioesters) in water. In addition, the direct amidation of aldehydes was achieved by the addition of the amines to the thioesterification reaction mixture in water. 相似文献