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151.
Shinji Tanimori Tatsuya Sunami Kouji Fukubayashi Mitsunori Kirihata 《Tetrahedron》2005,61(9):2481-2492
A reaction of chiral enyne 22 derived from l-proline with a catalytic amount of cobalt (0) octacarbonyl in the presence of N-methylmorphorine N-oxide gave tricyclic enone 24 in 54% yield (73% based on consumed starting material). Treatment of enone 11 with aqueous methylamine followed by silica gel afforded bridged tetracyclic indolidine 1, a common structural motif of natural metabolites, an asperparaline series of compounds and also a potential intermediate for the synthesis of a paralytic alkaloid, asperparaline C (4), in 70% yield. 相似文献
152.
The radical addition of enolizable carbonyl compounds such as malonates and malononitrile to alkenes was successfully achieved through a catalytic process using the Mn(II)/Co(II)/O(2) system to afford the corresponding adducts in fair to good yields. Dimethyl malonate added to 1,5-cyclooctadiene to produce a fused bicycle compound. 相似文献
153.
Masahiko Okada Kouji Tachikawa Keigo Aoi 《Journal of polymer science. Part A, Polymer chemistry》1997,35(13):2729-2737
A series of polyesters were synthesized by the bulk polycondensations of the respective combinations of two difuranic diesters, i.e., bis(5-(methoxycarbonyl)-2-furyl)methane ( 4a ) and 1,1-bis(5-(methoxycarbonyl)-2-furyl)ethane ( 4b ), with two 1,4 : 3,6-dianhydrohexitols [1,4 : 3,6-dianhydro-D -glucitol ( 1 ) and 1,4 : 3,6-dianhydro-D -mannitol ( 2 )], four aliphatic diols, and three oligo(ethylene glycol)s. The polycondensations were carried out at 220–230°C in the presence of titanium isopropoxide as a catalyst, giving polyesters having number average molecular weight up to 2.4 × 104. These polyesters are soluble in a variety of solvents including chlorinated hydrocarbons, 1,4-dioxane, dimethyl sulfoxide, dimethylformamide, and sulfolane. Soil-burial tests along with enzymatic degradation experiments showed that these polyesters are potentially biodegradable. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2729–2737, 1997 相似文献
154.
Niki Prastomo Kouji Kimata Yusuke Daiko Hiroyuki Muto Toshihiro Kogure Mototsugu Sakai Atsunori Matsuda 《Journal of Sol-Gel Science and Technology》2010,56(3):345-352
SiO2·TiO2 coatings were prepared by a sol–gel route. The effect of the external fields including mechanical vibration and electric
charge applied during hot-water treatment on titania precipitation at the surface of the coatings was investigated. The shape
of the resulting precipitates tended to elongate by applying vibration in a parallel or perpendicular direction, or by applying
an electric charge. The organization of titania nanocrystallites possibly occurs because of the concentration gradient of
dissolved titania species generated by the external fields during the hot-water treatment. A maximum aspect ratio of 38.1
was achieved for the precipitate prepared by hot-water treatment performed under parallel vibration for 5 h. The shape of
the resulting precipitates was also influenced by the content of TiO2 in the SiO2·TiO2 coating, with a smaller proportion of TiO2 increasing the aspect ratio of the resulting precipitate. 相似文献
155.
Jyunichi Koyanagi Katsumi Yamamoto Kouji Nakayama Akira Tanaka 《Journal of heterocyclic chemistry》1995,32(4):1289-1291
Reaction of the parent naphtho[2,3-b]furan-4,9-dione 2 with various electrophilic reagents was difficult, and only nitration of 2 gave small amounts of 2-nitronaphtho[2,3-b]furan-4,9-dione 4 . Then 2-acetylnaphtho[2,3-b]furan-4,9-dione 1 was not obtained by the acetylation of 2 . On the other hand, compound 1 that is isolated from Tabebuia Cassinoides and has cytotoxic activity, was obtained from 3-lithiofuran in five steps. 相似文献
156.
[structure: see text]. The syntheses of three fragments, 2, 3, and 4, of amphidinolide B1 have been accomplished. The 1,3-isomerization of allylic alcohol 10 was accomplished via rhenium oxo catalysis and has been applied successfully in the synthesis. (-)-MIB-catalyzed asymmetric vinylzinc addition to aldehyde 31 and the regio- and stereoselective epoxidation of unsymmetrical divinyl methanol 32 were key steps. 相似文献
157.
Takaya Yoshida Koji Nakabayashi Hiroko Tokoro Marie Yoshikiyo Asuka Namai Kenta Imoto Kouji Chiba Shin-ichi Ohkoshi 《Chemical science》2020,11(33):8989
Atomic vibrations due to stretching or bending modes cause optical phonon modes in the solid phase. These optical phonon modes typically lie in the frequency range of 102 to 104 cm−1. How much can the frequency of optical phonon modes be lowered? Herein we show an extremely low-frequency optical phonon mode of 19 cm−1 (0.58 THz) in a Rb-intercalated two-dimensional cyanide-bridged Co–W bimetal assembly. This ultralow frequency is attributed to a millefeuille-like structure where Rb ions are very softly sandwiched between the two-dimensional metal–organic framework, and the Rb ions slowly vibrate between the layers. Furthermore, we demonstrate temperature-induced and photo-induced switching of this low-frequency phonon mode. Such an external-stimulation-controllable sub-terahertz (sub-THz) phonon crystal, which has not been reported before, should be useful in devices and absorbers for high-speed wireless communications such as beyond 5G or THz communication systems.Extremely low-frequency optical phonon mode in Rb-intercalated two-dimensional cyanide-bridged Co–W bimetal assembly and its temperature- and photo-induced switching effect. 相似文献
158.
Dewa T Sugiura R Suemori Y Sugimoto M Takeuchi T Hiro A Iida K Gardiner AT Cogdell RJ Nango M 《Langmuir : the ACS journal of surfaces and colloids》2006,22(12):5412-5418
A unique method is described for directly observing the lateral organization of a membrane protein (bacterial light-harvesting complex LH2) in a supported lipid bilayer using total internal reflection fluorescence (TIRF) microscopy. The supported lipid bilayer consisted of anionic 1,2-dioleoyl-sn-glycero-3-[phospho-rac-(1'-glycerol)] (DOPG) and 1,2-distearoly-sn-3-[phospho-rac-(1'-glycerol)] (DSPG) and was formed through the rupture of a giant vesicle on a positively charged coverslip. TIRF microscopy revealed that the bilayer was composed of phase-separated domains. When a suspension of cationic phospholipid (1,2-dioleoyl-sn-glycero-3-ethylphosphocholine: EDOPC) vesicles (approximately 400 nm in diameter), containing LH2 complexes (EDOPC/LH2 = 1000/1), was put into contact with the supported lipid bilayer, the cationic vesicles immediately began to fuse and did so specifically with the fluid phase (DOPG-rich domain) of the supported bilayer. Fluorescence from the incorporated LH2 complexes gradually (over approximately 20 min) spread from the domain boundary into the gel domain (DSPG-rich domain). Similar diffusion into the domain-structured supported lipid membrane was observed when the fluorescent lipid (1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-lissamine-rhodamine B sulfonyl: N-Rh-DOPE) was incorporated into the vesicles instead of LH2. These results indicate that vesicles containing LH2 and lipids preferentially fuse with the fluid domain, after which they laterally diffuse into the gel domain. This report describes for first time the lateral organization of a membrane protein, LH2, via vesicle fusion and subsequent lateral diffusion of the LH2 from the fluid to the gel domains in the supported lipid bilayer. The biological implications and applications of the present study are briefly discussed. 相似文献
159.
Kwang‐Hoi Lee Ho‐Jin Lee Kouji Kuramoto Yohei Tanaka Kazuhide Morino Atsushi Sudo Tatsuo Okauchi Akihito Tsuge Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2011,49(1):234-241
Soluble polythiophenes bearing strong electron withdrawing groups, dicyanoethenyl [? CH?C(CN)2] (PTDCN) and cyano‐methoxycarbonylethenyl [? CH?C(CO2Me)CN] (PTCNME), in the side chains have been prepared. Optical band gaps calculated from onset absorption were 1.70 eV and 1.73 eV for PTDCN and PTCNME, respectively. Highest occupied molecular orbital energy levels measured with a surface analyzer (AC‐2) were ?5.53 eV and ?5.29 eV for PTDCN and PTCNME, respectively, which were much lower than that of poly(3‐hexylthiophene) (?4.81 eV). To investigate photovoltaic properties, bulk heterojunction polymer solar cells based on PTDCN and PTCNME were fabricated with a structure of ITO/PEDOT:PSS/active layer/LiF/Al, where the active layer was a blend film of polymer and [6,6]‐phenyl C61 butyric acid hexyl ester (PC61BH). Solar cell parameters were estimated from current density–voltage (J–V) characteristics under the illumination of AM1.5 at 100 mW/cm2. The solar cell based on the blend film of PTCNME:PC61BH (1:1) showed power conversion efficiency (PCE) of 0.72% together with the open current voltage (Voc) of 0.61 V, the short current density (Jsc) of 3.90 mA/cm2, and the fill factor of 30.3%. The PCE of a solar cell fabricated from PTDCN in a similar way was 0.56%. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
160.
Kwang‐Hoi Lee Ho‐Jin Lee Kouji Kuramoto Yohei Tanaka Kazuhide Morino Atsushi Sudo Tatsuo Okauchi Akihiko Tsuge Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2011,49(16):3543-3549
π‐Conjugated polymers, PTOTBT , PTEHTBT , and PTt‐BTBT , composed of benzothiadiazole as an electron accepting unit and terthiophene as an electron donating unit in the backbone were prepared. PTOTBT , PTEHTBT , and PTt‐BTBT contained side chain groups of n‐octyl, 2‐ethylhexyl, and t‐butyl groups, respectively. Solubility, optical and thermal properties of the polymers showed strong dependences on their side chain groups. PTEHTBT having 2‐ethylhexyl groups in the side chain exhibited absorption maximum (λmax) at longer wavelength (565 nm) than PTOTBT (534 nm) and PTt‐BTBT (495 nm). PTOTBT showed higher thermal stability than the others. The prepared polymers were employed to polymer solar cells (PSCs) with a configuration of ITO/PEDOT‐PSS/polymer: PC61BH/LiF/Al. Power conversion efficiency of the PSC‐based on PTEHTBT was 1.32%. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献