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131.
Takahide Mizawa Katsuhiko Takenaka Tomoo Shiomi 《Journal of polymer science. Part A, Polymer chemistry》2000,38(1):237-246
The synthesis of heterotelechelic poly(methyl methacrylate) (PMMA) containing α‐maleimide‐ω‐dienyl end‐groups and its subsequent intramolecular cyclization are described. The anionic polymerization of methyl methacrylate was carried out with 3‐tert‐butyldimethylsilyloxypropyl‐1‐lithium and 5‐bromo‐1,3‐pentadiene as the initiator and terminator, respectively, to synthesize α‐hydroxy‐ω‐dienyl‐PMMA. The introduction of the maleimide group to the α chain end by the reaction of the sodium salt of the polymer with N‐(3‐chloromethylphenyl)‐maleimide or N‐(3‐bromomethylphenyl)‐maleimide was not successful because of the nucleophilic addition of alkoxide to the carbon carbon double bond of the maleimide group. When 4,4′‐bismaleimidediphenylether was allowed to react with the alkoxide, the aimed α‐maleimide‐ω‐dienyl‐PMMA was obtained in a good yield. Ring closure by the intramolecular Diels–Alder reaction was carried out by the heating of the dilute polymer solution in tetrahydrofuran. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 237–246, 2000 相似文献
132.
Safni Toyohide Takeuchi Tomoo Miwa Yoshimi Hashimoto Hiroyuki Moriyama 《Journal of chromatography. A》1999,850(1-2):65-72
Effects of eluent composition on retention behavior of inorganic anions have been investigated in ion chromatography using anion-exchangers modified with heparin. Both cation and anion of the eluent affected the retention of analyte anions and unusual retention behavior was observed on the modified stationary phase. The retention time of anions decreased with decreasing eluent concentration when sodium sulfate, magnesium sulfate and chlorides of alkali metals were used as the eluent, whereas it increased with decreasing eluent concentration when aluminum sulfate, copper sulfate and sulfuric acid were used as the eluent. The retention of nitrate increased in the order of Li+, Na+, K+, Rb+ and Cs+ when their chlorides were used as the eluent. When sodium perchlorate and chlorides of alkaline-earth metals were used as the eluent, the eluent should include heparin. Otherwise, the modifier was partially bled from the column. 相似文献
133.
Dr. Naoya Oku Atsumi Hasada Kenji Kimura Dr. Hideharu Honoki Prof. Dr. Ryo Katsuta Prof. Dr. Arata Yajima Prof. Dr. Tomoo Nukada Prof. Dr. Ken Ishigami Prof. Dr. Yasuhiro Igarashi 《化学:亚洲杂志》2021,16(11):1493-1498
Ether lipids are a minor group of glycerolipids but widespread in nature, playing a vital function as membrane lipids, signalling molecules, or buoyant material. We have discovered sulfoquinovosylchimyl alcohol ( 1 ), a sulfonate-substituted glyceroglycolipid, from a lake ball-forming green alga Aegagropilopsis moravica (family Pithophoraceae), with the guidance of antimicrobial activity. The structure of 1 , including absolute configurations of all sterogenic centers, was established by extensive NMR analysis, chemical degradation studies, and finally by total synthesis. Lipid 1 is an ether variant of a lyso-form of sulfoquinovosyldiacylglycerol, a chloroplast-specific membrane lipid, and thus represents a new lipid class, sulfoquinovosylglyceryl ether. A high occurrence of mobile life form in the family Pithophoraceae and a unique behaviour of chloroplasts reported in closely related Aegagropila linnaei, the famous lake-ball alga, implies a possible role of lipid 1 or its acyl derivatives in ecological adaptation to dysphotic niches. 相似文献
134.
135.
In this review, we describe the development by our research group of highly functionalized heterogeneous Olympic medal metal (gold, silver, and copper) nanoparticle catalysts using hydrotalcite as a support, aimed towards Green and Sustainable Chemistry. Olympic medal metal nanoparticles can cooperate with the basic sites on the hydrotalcite surface, providing unique and high performance catalysis in environmentally-benign organic transformations such as aerobic oxidation of alcohols, lactonization of diols and selective deoxygenation of epoxides and nitro aromatic compounds. 相似文献
136.
Hitoshi Ohta S. Okubo N. Souda M. Tomoo T. Sakurai T. Yoshida E. Ohmichi M. Fujisawa H. Tanaka R. Kato 《Applied magnetic resonance》2009,35(3):399-410
A multiextreme (high-field, low-temperature, high-pressure and nanoscale) electron spin resonance (ESR) measurement system
is under development in Kobe. In this connection, our recent development is introduced and two applications of our high-frequency
high-field ESR are described. High-frequency high-field ESR measurements of dioptase (Cu6Si6O18·6H2O), which has an interesting antiferromagnetic Cu2+ network, have been performed using a pulsed magnetic field of up to 55 T. Antiferromagnetic resonances (AFMR) are clearly
observed at 4.2 K with the light sources of up to 1017 GHz. However, a deviation from the conventional two-sublattice AFMR
theory is observed in the high field. Temperature dependence of the X-band and high-frequency ESR has been also observed in
the triangular lattice antiferromagnet EtMe3P[Pd(dmit)2]2 which shows the spin-Peierls-like transition below T
c = 25 K. The preliminary field dependence of the spin gap estimated from the analyses of our ESR results has been shown in
connection with the previous magnetic susceptibility results. 相似文献
137.
Yukiko Maekawa Makiko Sugiura Atsuko Takeuchi Koji Tomoo Toshimasa Ishida Miyoko Kamigauchi 《Helvetica chimica acta》2010,93(5):991-998
The Advanced Glycation End Products (AGEs) are the causative substances of lifestyle‐habit illness. To elucidate the glycation mechanism of the protein, the reaction of lysozyme with D ‐glucose was analyzed by the fluorescence, TOF‐MS, and 13C‐NMR spectroscopy under the physiological condition. The fluorescence intensity of lysozyme in the glycation solution increased proportionally with a reaction time of ten weeks. The MALDI‐TOF‐MS spectra of the reaction solution after two weeks showed a peak at m/z 15066, which indicated the presence of a larger molecule than the native lysozyme (m/z 14331), and new peaks at m/z 30105 (dimer) and 45000 (trimer) were also observed. The spectral analysis supported the assumption of a continuous glycation reaction of D ‐glucose with lysozyme and a 30% transformation of lysozyme to the dimeric form during ten weeks. The 13C‐NMR spectra of lysozyme showed six [13C]‐labeled signals by the glycation reaction with [13C]‐glucose after two weeks of reaction. The combined analysis of TOF‐MS and 13C‐NMR spectra uncovered that first products of the glycation reaction of lysozyme with D ‐glucose can be observed already three hours after starting the reaction and that nine D ‐glucose units are attached during ten weeks at 37°. 相似文献
138.
Kohki Ebitani Masaki Kato Ken Motokura Tomoo Mizugaki Kiyotomi Kaneda 《Research on Chemical Intermediates》2006,32(3-4):305-315
Montmorillonite-enwrapped titanium hydroxide species (Ti4+-mont) acted as a highly efficient heterogeneous acid catalyst for the acylation of aromatic compounds with acid anhydrides or carboxylic acids. The catalytic activity of the Ti4+-mont was higher than those of other acid catalysts such as zeolites, SO 4 2? /ZrO2 and p-toluenesulfonic acid. For example, the reaction of anisole with dodecanoic acid in the presence of the Ti4+-mont catalyst gave 1-(4-methoxyphenyl)-1-dodecanone in 97% yield. Furthermore, the Ti4+-mont catalyst was easily separated from the reaction mixture and was recyclable. 相似文献
139.
Hara T Kanai S Mori K Mizugaki T Ebitani K Jitsukawa K Kaneda K 《The Journal of organic chemistry》2006,71(19):7455-7462
A calcium vanadate apatite (VAp), in which PO4(3-) of hydroxyapatite (HAP), Ca10(PO4)6(OH)2, is completely substituted by VO4(3-) in the apatite framework, was synthesized. Physicochemical analysis of the VAp reveals the presence of isolated VO4 tetrahedron units with a pentavalent oxidation state. The VAp acts as a high-performance heterogeneous base catalyst for various carbon-carbon bond-forming reactions such as Michael and aldol reactions in aqueous media and the H-D exchange reactions using deuterium oxide. For example, a 200-mmol-scale Michael reaction under triphasic conditions proceeded rapidly, with an extremely high turnover number of up to 260 400 and an excellent turnover frequency of 48 s(-1). No vanadium leaching was detected during the above reactions, and the catalyst was readily recycled with no loss of activity. 相似文献
140.
Ryo Katsuta Mami Toyoda Arata Yajima Ken Ishigami Tomoo Nukada 《Tetrahedron letters》2018,59(11):1010-1013
The absolute stereochemistry of an aspergilli-derived peptide enamide, JBIR-81, was determined to be 12S, 15S by the first synthesis of (12S,15S)-JBIR-81 and its epimer. The overall yield was 56% over six steps from N-methyl-l-leucine. The (Z)-enamide structure was effectively constructed with use of a copper (I) catalyzed coupling reaction between a vinyl halide and a carboxamide. 相似文献