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排序方式: 共有120条查询结果,搜索用时 453 毫秒
1.
Kazuhiro Kobayashi Atsushi Takanohashi Kenichi Hashimoto Osamu Morikawa Hisatoshi Konishi 《Tetrahedron》2006,62(44):10379-10382
A facile synthetic method for 4,5-diaminopyrrolo[1,2-a]quinoline derivatives has been developed. Treatment of 2-(pyrrol-1-yl)benzaldehydes with secondary amine hydrochloride/NaI/TMSCl/Et3N in the presence of an isocyano compound leads to the formation of 4-alkyl(or aryl)amino-5-dialkylaminopyrrolo[1,2-a]quinolines. 相似文献
2.
Atsushi TatamiMasayuki Inoue Hisatoshi UeharaMasahiro Hirama 《Tetrahedron letters》2003,44(28):5229-5233
A concise route to the HIJKLM-ring fragment 10 of ciguatoxin (CTX) and 51-hydroxyCTX3C was developed in which oxiranyl anion addition and intramolecular carbonyl olefination were utilized as key transformations. The present procedure requires only 23 steps from the I-ring 5, while 35 steps were employed in a previous synthesis of the corresponding right wing 11 of CTX3C. The high efficiency of the present synthesis ensures a supply of 10 for total synthesis and biomedical applications. 相似文献
3.
A chiral water-soluble zinc porphyrin was optically resolved on a chiral HPLC column, and the binding of chiral amino acids and peptides to each of the enantiomers was examined spectrophotometrically in basic aqueous solution. The binding data apparently indicated that the zinc porphyrin has chiral selectivity for amino acids and dipeptides. This was reasonably explained in terms of the triple cooperation of coordination, Coulomb, and steric interactions of the chiral amino carboxylates with the porphyrin. A compensatory relationship among the thermodynamic parameters for chiral recognition was also shown. 相似文献
4.
The sequential Sonogashira reaction and the cyclization reaction of various 2-iodoanilines and terminal alkynes in the presence of a palladium catalyst and tetrabutylammonium fluoride (TBAF) gave the corresponding 2-substituted indoles in good yields. 相似文献
5.
Kazuhiro Kobayashi Yasutoshi Himei Shuhei Fukamachi Miyuki Tanmatsu Osamu Morikawa Hisatoshi Konishi 《Tetrahedron》2007,63(20):4356-4359
Heating mixtures of 2-(pyrrol-1-yl)benzaldehydes and aryl amines under argon afforded 9-arylamino-9H-pyrrolo[1,2-a]indoles, via cyclization of the resulting 2-(pyrrol-1-yl)benzaldimine intermediates. Heating in the presence of oxygen afforded (Z)-9-arylimino-9H-pyrrolo[1,2-a]indoles, which were successfully hydrolyzed with hydrochloric acid to give pyrrolo[1,2-a]indol-9-ones. 相似文献
6.
7.
Hisatoshi Kura Kan Fujihara Akira Kimura Teruhisa Ohno Michio Matsumura Yoshinori Hirata Tadashi Okada 《Journal of Polymer Science.Polymer Physics》2001,39(23):2937-2946
The anthracene‐sensitized photodecomposition of diphenyliodonium hexafluorophosphate was studied in an epoxy matrix. From steady‐state photolysis, the generation of protons, which are considered to be the actual initiators of the polymerization of epoxides, was confirmed. In addition, 9‐phenylanthracene was detected as a main product from anthracene. From time‐resolved laser‐flash photolysis, a broad absorption band with a peak at about 500 nm was observed that was thought to be due to the precursor of 9‐phenylanthracene. On the basis of these results, we propose electron transfer from anthracene in the excited singlet state to the diphenyliodonium cation as the initial step of photoacid generation. This process is followed by fast chemical reactions, which generate 9‐phenylanthracene and protons, and back electron transfer from the diphenyliodine radical to the anthracene cation radical. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2937–2946, 2001 相似文献
8.
Hisatoshi Ikai 《Linear algebra and its applications》2011,434(4):1094-1106
Based on the relation of exponential maps and interior products in exterior algebras, some formulas of Pfaffians, including expansion formulas and the Cayley-Jacobi formula for determinants of alternating matrices, are deduced with new proofs. As an application, Pfaffian powers of alternating bilinear forms [O. Loos, Discriminant algebras and adjoints of quadratic forms, Beiträge Algebra Geom. 38 (1997) 33-72] are interpreted in terms of exponential maps in algebras of alternating multi-linear forms. 相似文献
9.
Hisatoshi Ikai 《Monatshefte für Mathematik》2003,139(1):33-60
Usual constructions of spin and Clifford groups, restricted to the case where the basic quadratic spaces is hyperbolic, are
examined as those of group schemes over a commutative ring. Not surprisingly they yield indeed smooth and reductive group
schemes, but the proof involves a lot of calculation and uses a connection with Jordan pairs. Maximal tori and their associated
root data are also constructed explicitly.
Received November 6, 2001; in revised form September 5, 2002
Published online May 9, 2003 相似文献
10.
Spectroscopic measurements of excited particles in a N2 gas RF plasma-assisted carbon laser ablation
M.A. Bratescu N. Sakura D. Yamaoka Y. Sakai H. Sugawara Y. Suda 《Applied Physics A: Materials Science & Processing》2004,79(4-6):1083-1088
In this work, we investigated a carbon plasma plume produced by laser ablation of a graphite target in a nitrogen gas environment. The spatial distributions of C and N atoms were measured by time-resolved absorption spectroscopy. The spatial distributions of the relative densities of CN radicals, C2, and C3 molecules were measured using time-resolved emission spectroscopy. We determined that nitrogen gas produced an increase in carbon atom and molecule densities in the ablation plume. It was observed that the addition of RF plasma to the plume increased the CN radicals and C atom densities, and decreased the C2 and C3 molecule densities. The RF plasma changed the evolution of various fractional species of C, N, CN, C2, and C3 in the ablation plume. The chemical reactions with and without RF plasma were explained using the evolution and density of the fractional species of C, N, CN, C2, and C3in the plume. PACS 52.38.Mf; 42.62.Fi; 33.20.-t; 81.05.Uw 相似文献