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231.
232.
Dehydrogenative cis double phosphorylation of terminal alkynes with H-phosphonate took place efficiently in the presence of a divalent palladium catalyst to afford (Z)-bisphosphoryl-1-alkenes selectively. 相似文献
233.
Photoinduced Charge‐Transfer State of 4‐Carbazolyl‐3‐(trifluoromethyl)benzoic Acid: Photophysical Property and Application to Reduction of Carbon−Halogen Bonds as a Sensitizer
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Prof. Dr. Ryosuke Matsubara Toshiyuki Shimada Prof. Dr. Yasuhiro Kobori Tatsushi Yabuta Prof. Dr. Toshiyuki Osakai Prof. Dr. Masahiko Hayashi 《化学:亚洲杂志》2016,11(14):2006-2010
The photoinduced persistent intramolecular charge‐transfer state of 4‐carbazolyl‐3‐(trifluoromethyl)benzoic acid was confirmed. It showed a higher catalytic activity in terms of yield and selectivity in the photochemical reduction of alkyl halides compared to the parent carbazole. Even unactivated primary alkyl bromides could be reduced by this photocatalyst. The high catalytic activity is rationalized by considering the slower backward single‐electron transfer owing to the spatial separation of the donor and acceptor subunits. 相似文献
234.
Ikeda M Minari J Shimada N Numata M Sakurai K Shinkai S 《Organic & biomolecular chemistry》2007,5(14):2219-2224
A cationic polysaccharide bearing a beta-1,3-glucan main-chain structure (CUR-N(+)) forms a complex with a hetero-sequence oligonucleotide, that is, a CpG ODN, and facilitates the transportation of the resultant complex into a murine macrophage-like cell J774.A1, which induces an efficient secretion of a cytokine (IL-12) as compared with that induced by conventional carriers such as poly(ethyleneimine) (PEI) and poly(L-lysine) (PLL). 相似文献
235.
A newly developed vacuum hot press system has been specially designed for the thermal bonding of glass substrates in the fabrication process of Pyrex glass microchemical chips. This system includes a vacuum chamber equipped with a high-pressure piston cylinder and carbon plate heaters. A temperature of up to 900 degrees C and a force of as much as 9800 N could be applied to the substrates in a vacuum atmosphere. The Pyrex substrates bonded with this system under different temperatures, pressures, and heating times were evaluated by tensile strength tests, by measurements of thickness, and by observations of the cross-sectional shapes of the microchannels. The optimal bonding conditions of the Pyrex glass substrates were 570 degrees C for 10 min under 4.7 N/mm(2) of applied pressure. Whereas more than 16 h is required for thermal bonding with a conventional furnace, the new system could complete the whole bonding processes within just 79 min, including heating and cooling periods. Such improvements should considerably enhance the production rate of Pyrex glass microchemical chips. Whereas flat and dust-free surfaces are required for conventional thermal bonding, especially without long and repeated heating periods, our hot press system could press a fine dust into glass substrates so that even the areas around the dust were bonded. Using this capability, we were able to successfully integrate Pt/Ti thin film electrodes into a Pyrex glass microchip. 相似文献
236.
237.
Kanamitsu N Osaki T Itsuji Y Yoshimura M Tsujimoto H Soga M 《Chemical & pharmaceutical bulletin》2007,55(12):1682-1688
We developed new intravenous sedative-hypnotic compounds with the isoindolin-1-one skeleton focusing on the water-soluble property and in vivo safety. We synthesized approximately 170 derivatives and evaluated their hypnotic effects by intravenous administration of the compounds to mice. A series of the 2-phenyl-3-[2-(4-methyl-1-piperazinyl)-2-oxoethyl]isoindolin-1-one analogs, 3(-), 5(-), 27(-), and 47(-) [JM-1232(-)], showed potent sedative-hypnotic activity with good water solubility and a wide safety margin. The hypnotic doses (HD50s) of these 4 compounds when administered to mice were 2.35, 1.90, 2.17, and 3.12 mg/kg, respectively, and the lethal doses (LD50s) were 88.67, 64.69, >120, and >120 mg/kg, respectively. The therapeutic indexes (LD50/HD50) were 37.73, 34.05, >55.30, and >38.46, respectively. Among these compound, 47(-) [JM-1232(-)] is being considered as the most potential candidate for clinical trials in humans. 相似文献
238.
Kiyoshi Tanaka Tohru Kurushima Satoru Iwata Syunsuke Shimada 《Journal of heterocyclic chemistry》2007,44(2):303-307
239.
Toshiyuki Itoh Manabu Kanbara Shuichi Hayase Takashi Kato Yumiko Takagi 《Journal of fluorine chemistry》2007,128(10):1112-1120
The synthesis of a novel chiral gem-difluorocyclopropane building block has been accomplished using chemo-enzymatic reaction protocol; the prochiral diol of 1,4-bis(2,2-difluoro-3-(hydroxymethyl)cyclopropyl)benzene (5) was converted to the corresponding chiral diacetate by Pseudomonas lipase (lipase SL-25, Meito)-catalyzed transesterification with vinyl acetate as acyl donor with >99% enantiomeric excess. Various types of diesters or dialkyl ether were prepared from the diol and their helical twisting power (HTP) was evaluated by addition of 1.0 wt% to a non-chiral nematic liquid crystal host; the HTP was significantly dependent on the structure of ester or ether moieties and diester of diol 5 with isopropylfumalic acid showed the largest HTP. 相似文献
240.
T. Shimada K. Hiruma M. Shirai M. Yazawa K. Haraguchi T. Sato M. Matsui T. Katsuyama 《Superlattices and Microstructures》1998,24(6):453-458
The self-organized, position-controlled and parallel growth of GaAs and InAs nanowhiskers is successfully demonstrated by using a metal–organic chemical vapour deposition method. The growth takes place preferentially along the 111 As direction with the aid of the catalytic effect of Au nanodroplets, and not along 111 Ga or In directions. The diameter and length of the whisker can be controlled artificially down to 10 nm and to over 1 μm, respectively. Doping and composition control of p- or n-type such as GaAs–InAs heterostructure formation are possible along the length direction of the whisker by changing the source gases. In order to control the growth position of the whisker, positioning of a Au nanodroplet is essential and realized by a lithographic method. By choosing the [111]B direction to the substrate surface and normal to the patterned side edges, and by positioning the Au nanodroplet on the side wall, the positioned planar nanowhisker growth and bridging are successfully demonstrated. The growth mechanism of the nanowhiskers is revealed by the scanning and transmission electron microscope observations. Nanometer-size Au-alloy droplets play an important role in the growth of the whiskers. The whisker growth process is governed by the vapor–liquid–solid growth mechanism. 相似文献