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1.
Tomooka K Komine N Fujiki D Nakai T Yanagitsuru S 《Journal of the American Chemical Society》2005,127(35):12182-12183
Remarkably stable planar chirality was found in a nine-membered diallylic cyclic ether. Enantiomerically enriched ether was prepared by a kinetic resolution of a racemic one, which is valuable as a novel type of chiral building block. 相似文献
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Retention behavior of bile acid derivatives using cyclodextrin in the mobile phase in high-performance liquid chromatography 总被引:1,自引:0,他引:1
The retention behavior of 3-(1-anthroyl)bile acids together with bile acid glucuronides, sulfates, and 12-dehydro derivatives is examined by the addition of cyclodextrin to the mobile phase in reversed-phase high-performance liquid chromatography. The data suggest that the functional group at the 12 position of the steroid moiety may be the important factor for the formation of the inclusion complex from the solute and cyclodextrin. The separation of these bile acid derivatives is much improved by this inclusion chromatography. 相似文献
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Katsuhiko Tomooka Nobuyuki Komine Tomoya Sasaki Hideo Shimizu Takeshi Nakai 《Tetrahedron letters》1998,39(52):2362-9718
Treatment of (E)-6-phenyl-5-hexenyl carbamates with s-BuLi/(−)-sparteine is shown to afford the trans-1,2-disubstituted cyclopentane derivatives in high % ee, along with the bicyclo[3.1.0]hexanes (bicyclization products). 相似文献
5.
Dr. Tatsuya Nishimaru Dr. Kohei Eto Dr. Keita Komine Prof. Dr. Jun Ishihara Prof. Dr. Susumi Hatakeyama 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(33):7927-7934
The first total synthesis of lajollamycin B, a structurally novel nitro-tetraene spiro-β-lactone/γ-lactone antibiotic, is described. The convergent synthesis involves the construction of the C8′–C11′ nitrodienylstannane and its coupling with the segment prepared from the C1′–C7′ ω-iodoheptadienoic acid and the right-hand heterocyclic fragment, which has been utilized for our previous syntheses of oxazolomycin A. The revision of the geometry of the terminal Δ10′, 11′-double bond from E to Z is also described for the structure of natural lajollamycin B. 相似文献
6.
Regioselective palladium-catalyzed monoarylation of azoles was achieved using iodobenzoate immobilized on an insoluble polymer support. The positional selectivity for the coupling reaction was dramatically influenced by the presence of CuI. No diarylation was observed in either case. Unsymmetrical diarylation was also obtained with the polymer support using sequential coupling reactions. 相似文献
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We have designed and operated a positive branch 6.3 mm diameter rod Nd:YAG unstable resonator oscillator with a 12 nsec, 200 mJ Q-switched output at 10 Hz repetition rate. When followed by a single 9 mm diameter Nd:YAG amplifier output energies up to 750 mJ were obtained with a divergence less than 0.5 mrad. 相似文献
8.
Stable crack growth and fracture at the interface of undensified LI-900 reusable surface insulation (RSI) tile and the Nomex strain isolation pad (SIP) of the space-shuttle thermal-protection system (TPS) were modeled by double-edged notch-tension specimens. These specimens were loaded under uniaxial tension or 50-Hz cyclic loading and the resultant stable crack growth leading to eventual fracture was monitored by a videocamera. These tests showed that successive local tear-outs due to local tensile overload in the RSI tile resulted in the interfacial fracture where the cracktip opening angle, CTOA, of the SIP was related to initiation and intermittent stable crack propagation. Fractures in similar static and dynamic test specimens using densified LI-900 RSI tiles occurred in the undensified regions of the RSI tiles. These failures were consistent with the above failure mechanism based on the local tensile strength of the undensified LI-900 RSI tile. The intermittent stable crack growth of undensified LI-900 RSI tile was reproduced by a deterministic, two-dimensional finite-element model with SIP of variable elastic moduli. 相似文献
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A higher generation dendron with a long-alkyl chain thiol (DA2-SH) induced the formation of nanoparticles with a small core with quite a narrow size distribution (1.5 +/- 0.1 nm), the self-assembly of one-dimensional arrays of these gold nanoparticles (DA2-Au), and the stabilization for the formation of the radical cation of the phenothiazine of DA2-Au nanoparticles from the interfacial one-electron oxidation of the nanoparticles with NOBF4. 相似文献
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Fumihiko Maekawa Okiru Komine Katsushige Sato Tomoyuki Kanamatsu Motoaki Uchimura Kohichi Tanaka Hiroko Ohki-Hamazaki 《BMC neuroscience》2006,7(1):1-13