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61.
62.
Akio Fukuzawa Hideki Matsue Mitsuhiko Ikura Tadashi Masamune 《Tetrahedron letters》1985,26(45):5539-5542
The structure of two new nortriterpenes, glycinoeclepins B and C, isolated from the aqueous extracts of roots of kidney bean and related structurally to glycinoeclepin A, a natural hatching stimulus for the soybean cyst nematode, has been elucidated to be formulas 2 and 3, respectively. 相似文献
63.
64.
(1,4,7,10-Tetraazacyclododecane) [diamine or (S)-alanine]-cobalt(III) complexes [diamine = ethylenediamine, 2-(aminomethyl)pyridine, (R)-1,2-propanediamine, (R,R)-1,2-diaminocyclohexane, trimethylenediamine and 2-methyl-1,3-diaminopropane] are prepared and characterized spectroscopically. The ligand field transitions occur at lower energies than those of the corresponding tetraamine analogues. Severe distortions caused by the too small size of the cyclic ligand are one of the origins. The distortions also exert influence upon circular dichroism spectra. 相似文献
65.
Yui T Tsuchino T Itoh T Ogawa M Fukushima Y Takagi K 《Langmuir : the ACS journal of surfaces and colloids》2005,21(7):2644-2646
Composite films of a meso-(tetramethylpyridinium)porphyrin (TMPyP) hybrid incorporated in mesoporous silica (MPS) and cast on a methyl viologen (MV2+)/titania nanosheet hybrid were synthesized and a light-induced charge separation between the two could be observed. These composite thin films were able to initiate a one-electron reduction of the MV2+ ions accompanied by the simultaneous decomposition of the TMPyP organic dye within the mesoporous silica channels. 相似文献
66.
A large macrocyclic compound with six para-phenylene rings and six amide moieties, which are alternately secondary and tertiary, was synthesized. In a stepwise synthesis, the final cyclization step was successful because a combination of three tertiary amides, which prefer a cis conformation, and two linear secondary amides would arrange both amino and carboxyl ends close to each other, while various sizes of macrocyclic compounds including the target cyclic trimer were generated in one-pot synthesis where three secondary amide bonds were formed. 相似文献
67.
The preparation of the angular and linear isomers of benzo-fused 1,4-dimethyl-2(1H)-quinolinones 3a–5a and their spectral data including 13C-nmr data are reported. Structural difference among 3a–5a is confirmed from the proximity effect in 1H- and 13C-nmr data and from the uv spectral pattern. 相似文献
68.
Takeshi Tsumuraya Scott A. Batcheller Satoru Masamune 《Angewandte Chemie (International ed. in English)》1991,30(8):902-930
The organometallic chemistry of the Group 14 elements E = Si, Ge, Sn in the 1980's is highlighted by the successful construction and characterization of three systems previously thought to be too reactive to exists: (1) three-membered ring compounds including cyclotrisilane, cyclotrigermane, and cyclotristannane, (2) molecules containing E? E double bonds including disilene, digermene, and distannene, and (3) strained polycycles containing a skeleton of Group 14 elements, such as bicyclo[1.1.0]tetrasilane, hexagemaprismane, and octasilacubane. The majority of these numerous compounds now available are fully substituted with bulky ligands to suppress the reactivity intrinsic to the systems. These compounds permit examinations of (1) the variation of physical and chemical properties of a system with these elements and also with the ligands and (2) how two systems are interrelated thermally and photochemically with the intermediacy of the divalent (carbene-like) species. Theoretical calculations on virtually all of the parent compounds discussed in this review are evaluated alongside the experimental results. Some polycycles may constitute a stepping-stone on the way to compounds with a triple bond. 相似文献
69.
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
70.
Mitsuo Takasugi Shigemitsu Nagao Tadashi Masamune Akira Shirata Kokichi Takahashi 《Tetrahedron letters》1979,20(48):4675-4678
The structures and antifungal activity of four new mulberry phytoalexins, designated as moracins E, F, G, and H, are described. 相似文献