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81.
Novel methods of synthesis of spiro acyloxyphosphoranes are described emphasizing the significance of the first isolated instance of these new species. Then, the no-catalyst alternating copolymerizations of the combinations of cyclic phosphorus(III) compounds (serving as nucleophilic monomer, MN) with acrylic acid derivatives and with α-keto acids (electrophilic monomer, ME) are mentioned. These copolymerizations proceed without added initiator. Spiro oxyphosphoranes play an important role in the copolymerization scheme in the equilibrium with the +MN - ME ? zwitterion, the key intermediate of the copolymerization. Finally, new reactions of spiro acyloxyphosphoranes with nucleophiles, alcoholysis and aminolysis polymerizations are presented. 相似文献
82.
Noboru Oyama Takeo Ohsaka Fumihiro Yoshimura Masaya Mizunuma Shuichiro Yamaguchi Norihiko Ushizawa 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10-11):1463-1473
The electrode characteristics of ion-selective electrodes (ISEs) for K+, Na+, NH4 +, and Ca2+ based on bilayer film coatings, where the inner layer films are electroactive electropolymerized ones and the outer layer films are composed of conventional ion-sensitive materials, have been examined. These ISEs of the coated-wire electrode type have no conventional internal reference solution and reference electrode, but the inner films may be considered to function as the “internal standard solution.” The ion selectivity coefficients and the activity range showing Nernstian response were almost comparable to those of conventional liquid-membrane electrodes. The bilayer-coated ISEs showed insensitivity to O2 and CO2, long-term stability, and little drift. It was also found that the electrode performance is practically unchanged after sterilization in an autoclave. The results demonstrate that the bilayer-coated ISEs examined are promising for the determination of K+, Na+, NH4 +, or Ca2+ activity in biological and environmental systems. 相似文献
83.
Masakatsu Sugimoto Kazuhiko Fujiwara Ryuhei Wakita Toshiyuki Kida Araki Masuyama Yohji Nakatsuji 《Supramolecular chemistry》2013,25(2-3):145-151
Abstract Acyclic multidentate ligands consisting of an oligooxyethylene chain (di-, tri-, tetra-, and penta-) and two terminal rigid quinaldate end groups were newly prepared and their complexation properties with alkali metal cations were estimated by the solvent extraction method to indicate a better affinity for K+. Among them, the tetraethylene glycol derivative showed the highest K+ binding on about the same level as 18-crown-6. Their conformations in solution and in the solid state were examined by using 1H- and 13C-NMR spectroscopy and X-ray crystal analyses, respectively. The better binding of K+ in comparison with the corresponding glymes or analogues having the same donor sites was reasonably explained by considering the effective co-ordination of the carbonyl oxygen of the ester groups and the parallel π-stacking interaction between two quinaldate surfaces. 相似文献
84.
85.
We have recently found that the reaction of α-keto acids (1) with phosphorus (III) compounds (3) yielded cyclic acyloxyphosphoranes(C-AOPs, 4), a new class of pentacovalent phosphorus species having a P-OC(O) group.1, 2) The present paper deals with a new reaction of glyoxylic acid (2) with 3 to give C-AOPs (5) having no substituent at the C-3 position. 1 is an α-keto acid whereas 2 can be taken as an α-formyl acid. Although it is well known in the field of organic chemistry that the formyl group often behaves differently from a keto group, the reaction of 2 with 3 provides an example in which both groups behave in a similar manner. 相似文献
86.
Kenichi Takeo Kimiko Nagayoshi Kenichi Nishimura Shinichi Kitamura 《Journal of carbohydrate chemistry》2013,32(8):1159-1177
Abstract The 8-methoxycarbonyloctyl β-glycosides of the trisaccharides O-β-d-Glcp-(1 → 6)- O-β-d-Glcp-(1 → 3)-d-Glcp and O-β-d-Glcp-(1 → 3)-O-[β-d -Glcp-(1 → 6)]-d-Glcp and of the tetrasaccharide O-β-d-Glcp-(1 → 3)-O-[β-d-Glcp-(1 → 6)]-O-β-d-Glcp-(1 → 3)-d-Glcp, corresponding to the fragments of schizophyllan, have been synthesized by using mono- to tetrasaccharide 1-thioglycosides as glycosyl donors, each bearing a participating benzoyl group in the 2-position, and N-iodosuccinimide and silver triflate as promoter. Saponification of the tri- and tetrasaccharide β-glycosides, followed by attachment to bovine serum albumin of the resulting sugar derivatives having a carboxyl group at the aglycon terminal, provided neoglycoproteins for immunological studies of the polysaccharide. 相似文献
87.
Mitsuru Kitamura Kenji KuboShogo Yoshinaga Hiroki MatsuzakiKantaro Ezaki Taisuke MatsuuraDaigo Matsuura Noriyuki FukuzumiKeiichiro Araki Masafumi Narasaki 《Tetrahedron letters》2014
A synthetic study of kosinostatin aglycone is reported. Synthesis of key intermediate lactone 3, which corresponds to the BCDE ring fragment, was accomplished, and the precursor BCD ring fragment 5 was synthesized via two routes. First, 5 was synthesized from 2,5-dimethoxybenzaldehyde 16 by the combination of typical known transformations including efficient application of non-aqueous OsO4 oxidation in the presence of PhB(OH)2. However the synthesis required 15 long steps, and its main difficulty was ortho-alkoxycarbonylmethylation of 1-naphthol. Next we attempted to apply our recently developed alkoxycarbonylmethylation of diazonaphthoquinone for the synthesis of 5, and 5 was successfully synthesized in 9 steps from the same starting compound 16. Finally, 5 was stereoselectively converted to lactone 3 via trifluoroacetic acid-mediated cyclization of the 3,4-epoxycylohexanecarboxylic acid derivative. 相似文献
88.
The aberration theory applied to co-axial optical systems is extended to off-axial systems, for which third-order aberration coefficients are considered. The derived aberrations are analyzed using three-dimensional ray bundles, spot diagrams, and image charts, and classified in relation to the system symmetry. This theory is very useful for optical designers, allowing them to clarify the relationship between the structures of off-axial optical systems and the corresponding off-axial aberrations. 相似文献
89.
Yoshiki K Kanamaru R Ryosuke K Hashimoto M Hashimoto N Araki T 《Optics letters》2007,32(12):1680-1682
We developed a compact polarization-mode converter for microscopy to control three-dimensional polarization at the focus. The converter consisted of two homogeneously aligned liquid-crystal spatial light modulators with eight independently controllable electrodes (segments), and a quarter-waveplate. The converter converted a linearly polarized beam to three polarization modes: two orthogonal linear polarizations and a pseudo-radial polarization. We applied the converter to second-harmonic-generation microscopy and demonstrated the detection of three-dimensional molecular orientation. 相似文献
90.
Back Cover: Amphiphilic Inclusion Spaces for Various Guests and Regulation of Fluorescence Intensity of 1,8‐Bis(4‐aminophenyl)anthracene Crystals (Chem. Eur. J. 11/2014) 下载免费PDF全文