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1.
Chitosan was partially N‐acylated by treatment with n‐fatty acid anhydrides in a homogeneous solution in 2 vol.‐% aqueous acetic acid‐methanol (1:2 v/v). The degree of substitution (d.s.) for N‐acyl groups in the water‐soluble N‐acylchitosan derivatives was in the range of 0.42–0.82 for N‐acetyl, 0.37–0.76 for N‐propionyl, 0.52–0.71 for N‐butyryl and 0.54–0.64 for N‐pentanoyl and ca. 0.58 for N‐hexanoyl, respectively.
2.
Akiko Tsuhako Jing-Qian He Mariko Mihara Naoko Saino Sentaro Okamoto 《Tetrahedron letters》2007,48(52):9120-9123
Ketones and aldehydes were effectively reduced to the corresponding alcohols (or their silyl ethers) by the reaction with CaH2 and R3SiCl in the presence of a catalytic amount of ZnCl2. In the absence of the carbonyl substrate, the reagent reduced R3SiCl to the corresponding hydrosilane under mild reaction conditions. 相似文献
3.
Hayashi A Fujimoto Y Ogawa Y Nakayama H Tsuhako M 《Journal of colloid and interface science》2005,283(1):57-63
Ammonium-ion-exchanged alpha-Zr(HPO(4))(2)H(2)O (alpha-ZrP) was obtained as a single phase with the interlayer distance of 9.4 A by the ion-exchange of proton with ammonium ion. The ammonium ion-exchanged alpha-ZrP could adsorb ill-smelling gases, such as formaldehyde and carboxylic acids (formic acid, acetic acid, propionic acid, and butyric acid). The adsorption amounts of carboxylic acids increased in the order, butyric acid相似文献
4.
In the dimethyl sulfoxide (DMSO)-metal oxide oxidation of alcohol to carbonyl compound, molybdenum oxides were the only useful catalytic reagents, and various alcohols were oxidized to the corresponding carbonyl compounds in high yields. 相似文献
5.
Akiko Tsuhako 《Tetrahedron letters》2008,49(46):6529-6532
Copper salts, such as CuCl, CuI, CuCl2 and Cu(OTf)2, were used to catalyze the intramolecular hydroamination of allenylamines to provide the corresponding 3-pyrrolines or 2-alkenylpyrrolidines. 相似文献
6.
Kojima T Kato F Teraoka R Matsuda Y Kitagawa S Tsuhako M 《Chemical & pharmaceutical bulletin》2007,55(3):407-411
Two novel pseudopolymorphs, methanolate and ethanolate of tamoxifen [(Z)-2-[4-(1,2-diphenyl-1-butenyl)phenoxy]-N,N-dimethylethylamine]citrate, were prepared in addition to forms A and B reported previously. Their crystalline forms were identified and characterized by powder and single crystal X-ray diffractometry, differential scanning calorimetry, thermogravimetric analysis, hot-stage microscopy, scanning electron microscopy and diffuse reflectance infrared Fourier-transform spectroscopy, and their physicochemical stability was also evaluated. The results of single crystal X-ray analysis and thermogravimetric analysis of methanolate and ethanolate suggested that the stoichiometry of tamoxifen citrate : methanol and tamoxifen citrate : ethanol could be composed of a 1 : 1 molecular ratio for both solvates. The results of physicochemical stability evaluations at 75 and 97% RH at 40 and 60 degrees C indicated that the metastable form A was quite stable for at least 2 months even under severe storage conditions, whereas methanolate immediately transformed to a crystalline mixture of forms A and B, and subsequently changed to the stable form B. 相似文献
7.
Intercalation of gaseous thiols and sulfides into Ag+ ion-exchanged aluminum dihydrogen triphosphate
Hayashi A Saimen H Watanabe N Kimura H Kobayashi A Nakayama H Tsuhako M 《Langmuir : the ACS journal of surfaces and colloids》2005,21(16):7238-7242
Ag(+) ion-exchanged layered aluminum dihydrogen triphosphate (AlP) with the interlayer distance of 0.85 nm was synthesized by the ion-exchange of proton in triphosphate with Ag(+) ion. The amount of exchanged Ag(+) ion depended on the concentration of AgNO(3) aqueous solution. Ag(+) ion-exchanged AlP adsorbed gaseous thiols and sulfides into the interlayer region. The adsorption amounts of thiols were more than those of sulfides, thiols with one mercapto group > thiol with two mercapto groups > sulfides, and depended on the amount of exchanged Ag(+) ion in the interlayer region. The thiols with one mercapto group were intercalated to expand the interlayer distance of Ag(+) ion-exchanged AlP, whereas there was no expansion in the adsorption of sulfide. In the case of thiol with two mercapto groups, there was observed contraction of the interlayer distance through the bridging with Ag(+) ions of the upper and lower sides of the interlayer region. 相似文献
8.
The phosphorylation of disaccharides by inorganic cyclo-triphosphate (P(3m)) with a six-membered ring was examined in aqueous solution. In the phosphorylation of cellobiose, lactose, and alpha,alpha-trehalose with P(3m), beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl 1-triphosphate, beta-D-galactopyranosyl-(1-->4)-beta-D-glucopyranosyl 1-triphosphate, and 3-O-triphospho-alpha-D-glucopyranosyl-(1-->1)-alpha-D-glucopyranoside were synthesized with maximum yields of 28%, 35%, and 20%, respectively. In the reactions of maltose and sucrose with P(3m), two phosphorylated products were obtained in yields of 42% and 58%, respectively. The main phosphorylated products were assigned to alpha-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl 1-triphosphate and beta-D-fructofuranosyl-(2-->1)-2-O-triphospho-alpha-D-glucopyranoside by heteronuclear multiple bond correlation (HMBC) NMR. The phosphorylation mechanism of disaccharides with P(3m) is discussed. 相似文献
9.
Intercalations of mercaptocarboxylic acid and dithiodicarboxylic acid in Mg-Al layered double hydroxide and their adsorption properties for heavy metal ions were examined. During the intercalation of mercaptocarboxylic acids, mercapto group was oxidized, and the corresponding dithiodicarboxylic acids were intercalated in the interlayer space of Mg-Al layered double hydroxide. The intercalation compounds adsorbed mercury and silver ions effectively, whereas there was no adsorption of copper ion practically. 相似文献
10.
Aki Hayashi Hirokazu Nakayama Taro Eguchi Nobuo Nakamura Mitsutomo Tsuhako 《Molecular Crystals and Liquid Crystals》2013,570(2):573-578
Abstract Two kinds of diethylenetriamine (2E3A) intercalation compounds of α-zirconium phosphate with different interlayer distances could be obtained by regulating the reaction time and temperature. Phase I (d = 10.2 Å) slowly transforms to Phase II(d = 15. 8 Å) with transformation enthalpy of 30 kJ-mol?1 in 2E3A aqueous solution. The conformation of 2E3A in Phase I and Phase II were confirmed to be bent and all trans (straight) forms by31P MAS NMR and XRD measurements. Two phases have different adsorption behavior for gaseous carboxylic acids. Phase II can adsorb considerable amount of carboxylic acids whereas Phase I adsorb a little. 相似文献