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1.
Takayama K Iwata M Hisamichi H Okamoto Y Aoki M Niwa A 《Chemical & pharmaceutical bulletin》2002,50(8):1050-1059
In order to develop novel and orally active phosphodiesterase (PDE) 4 inhibitors, random screening was performed using our chemical library to find YM-10335 possessing the 1,8-naphthyridin-2(1H)-one skeleton which is a completely different structure from rolipram. In this report, the syntheses and structure-activity relationships of the YM-10335 derivatives were described. Some compounds showed selective inhibitory activities for PDE 4 derived from human peripheral blood cells and no effect on the other PDE types (1, 2, 3, 5). The inhibition of the tumor necrosis factor-alpha (TNF-alpha) release in vitro and the carrageenan-induced pleurisy in rats were also described. 相似文献
2.
Koyuki Sakai Hiroki Nishiyama Shinsuke Inagi Ikuyoshi Tomita Yusuke Hibi Motonori Komura Keiji Nose Tomokazu Iyoda 《Journal of polymer science. Part A, Polymer chemistry》2019,57(24):E1-E8
A block copolymer composed of a flexible polar poly(ethylene glycol) (PEG) and a less polar liquid crystalline poly(allene) segments is prepared by the living coordination polymerization of an allene derivative possessing trans‐azobenzene‐containing mesogenic substituent by the use of a π‐allylnickel macroinitiator bearing PEG segment. The thin film of the block copolymer is prepared by the spin coating of its solution onto mica or silicon wafer which proves to possess perpendicularly oriented nanocylindrical microphase separated structures as supported by the differential calorimetric, polarized optical microscopic, grazing‐incidence small‐angle X‐ray scattering, transmission electron microscope, and atomic force microscope measurements. 相似文献
3.
Tsuji M 《The Journal of organic chemistry》2003,68(25):9589-9597
We have synthesized all three possible isomers of C-hydroxycarborane from the corresponding amines via diazotization. The O-protonated C-hydroxycarboranes were characterized using the NMR spectrum measurements. Attempts at generating of carboranyl carbocations were carried out by the solvolyses of C-tosylates and C-triflates, as well as by treatment with superacids. Anchimeric assistance of both homoconjugative and hyperconjugative substituents was also investigated, as demonstrated by a successful strategy devised for the solvolytic generation of a phenyl cation. However, we have not been able to chemically provide any evidence of carboranyl carbocations, although the carboranyl carbocation may be an intermediate in the decomposition of the C-carboranediazonium ion. 相似文献
4.
Masahiko Shibahara Motonori Watanabe Chang Yuan Kenta GotoTeruo Shinmyozu 《Tetrahedron letters》2011,52(26):3371-3375
In the solid state, multilayered [3.3]paracyclophanes (PCPs) 2-6 and tetracyanoethylene (TCNE) form charge-transfer (CT) complexes with a 1:1 stoichiometry. All the benzene rings overlapped each other. All the [3.3]PCP units and dione units assume chair conformations and the transannular distances are shorter than those of the corresponding free multilayered [3.3]PCP except for the dione unit in the four-layered dione 6. In the crystal-packing diagrams, the PCP and TCNE are located in alternating donor-acceptor stacking in columns, and effective short contacts are observed in the neighboring molecules. 相似文献
5.
Imoto M Matsui Y Takeda M Tamaki A Taniguchi H Mizuno K Ikeda H 《The Journal of organic chemistry》2011,76(15):6356-6361
Observations show that nitroanilines exhibit an unusually high S(N)Ar reactivity with OH(-) in aqueous media in reactions that produce nitrophenols. S(N)Ar reaction of 4-nitroaniline (2a) in aqueous NaOH for 16 h yields 4-nitrophenol (4a) quantitatively, whereas a similar reaction of 4-nitrochlorobenzene (1a) gave 4a in 2% yield together with recovered 1a in 97%, suggesting that the leaving ability of the NH(2) group far surpasses that of Cl under these conditions. An essential feature of S(N)Ar reactions of nitroanilines is probably that the NH(2) leaving group participates in a hydrogen-bonding interaction with H(2)O. Density functional theory (DFT) calculations for a set of 4-nitroaniline, OH(-), and H(2)O suggest a possible formation of a Meisenheimer complex stabilized by hydrogen-bonding interactions and a six-membered ring structure. The results obtained here contrast with conventional S(N)Ar reactivity profiles in which nitroanilines are nearly unreactive with nucleophiles in organic solvents. 相似文献
6.
Irwin M. Chaiken Akira Komoriya Motonori Ohno Fred Widmer 《Applied biochemistry and biotechnology》1982,7(5):385-399
Recent experiments in several laboratories have emphasized the benefits of proteolytic enzymes as effective catalysts for the formation of peptide bonds for synthesis and semisynthesis. This review summarizes successful applications in both stepwise synthesis for small peptides and fragment condensation to produce large polypeptides and proteins. 相似文献
7.
Motoyama Y Abe M Kamo K Kosako Y Nagashima H 《Chemical communications (Cambridge, England)》2008,(42):5321-5323
Novel ruthenium-encapsulating polysiloxane gels are prepared by treatment of polymethylhydrosiloxane with diols in the presence of (mu(3),eta(2),eta(3),eta(5)-acenaphthylene)Ru(3)(CO)(7), and act as reusable catalysts in the isomerization of alkenes without leakage of the catalyst species. 相似文献
8.
Muranaka A Shibahara M Watanabe M Matsumoto T Shinmyozu T Kobayashi N 《The Journal of organic chemistry》2008,73(22):9125-9128
A racemic mixture of three-layered [3.3]paracyclophane ([3.3]PCP), 1, has been resolved into two enantiomers, and their absolute configuration was determined from a comparison of experimental chiroptical properties and density functional theory (DFT) calculations. A simple model comprising two p-xylenes and 1,2,4,5-tetramethylbenzene (durene) was used to explain the origin of the chiroptical properties of the three-layered cyclophane system. 相似文献
9.
Shibahara M Watanabe M Iwanaga T Matsumoto T Ideta K Shinmyozu T 《The Journal of organic chemistry》2008,73(12):4433-4442
The synthesis of three- and four-layered [3.3]paracyclophanes ([3.3]PCPs) 3-5 has been accomplished by utilizing the (p-ethylbenzenesulfonyl)methyl isocyanide (EbsMIC) method. The structures of the three- to four-layered [3.3]PCPs 3- 5 and their diones 8, 10, and 11 have been elucidated based on the (1)H NMR spectra and finally by X-ray structural analysis. In the three-layered [3.3]PCP-dione 8, the trimethylene bridges of the [3.3]PCP unit assume a chair conformation similar to that of 2, while the [3.3]PCP-2,11-dione unit assumes a boat conformation different from that of [3.3]PCP-dione 1 with a chair conformation. On the other hand, the two [3.3]PCP units in three-layered [3.3]PCP 3 both assume a boat conformation. In the four-layered [3.3]PCP-dione 10, the two outer [3.3]PCP units assume a boat conformation while the inner dione unit has a chair conformation. The trimethylene bridges in the four-layered [3.3]PCP 4 are highly disordered even at -150 degrees C. All the outer benzene rings are distorted into a boat form while the inner ones are distorted into a twist form. In the electronic spectra, bathochromic shift and hyperchromic effect are observed, but the magnitude decreases with an increase in the number of layers and the spectra become structureless. In the charge-transfer (CT) bands of the three- to four-layered [3.3]PCPs 3- 5 with tetracyanoethylene (TCNE), two absorption maxima (lambda(max)) are observed. The effect of an increase in the layers becomes significant, and the changes in the longest wavelength lambda(max) values from two to three and three to four are ca. 60 and 50 nm, respectively. By comparison of the stereoisomeric four-layered [3.3]PCPs 4 (meso) and 5 (racemic), the helical arrangement of the trimethylene bridges of 5 shows a more efficient transannular pi-electronic interaction. In the three- to four-layered [3.3]PCP-diones, a magnitude of the CT interaction almost comparable to that of [3.3]PCP 2 was observed, and this indicates that the -CH(2)COCH(2)- bridges inhibit the CT interaction and that this tendency is supported by the calculated HOMO energy levels and observed oxidation potentials. Three- and four-layered [3.3]PCPs 3- 5 show reversible redox processes, and 4 and 5 show an electron-donating ability almost comparable to that of [3 6]CP. Very good correlation between the lambda(max) of the CT bands with TCNE and the oxidation potentials is observed. 相似文献
10.
Munehisa Yasuniwa Takahiro Murakami Motonori Ushio 《Journal of Polymer Science.Polymer Physics》1999,37(17):2420-2429
Annealing of poly(butylene terephthalate) (PBT) was studied by differential scanning calorimetry (DSC) and small angle X‐ray scattering (SAXS) measurement. A PBT sample was annealed at a recrystallization temperature where recrystallization occurs with a maximum rate in the heating process of the sample. In the subsequent annealing steps, the annealed sample was annealed repeatedly at the recrystallization temperatures, and the stepwise annealing sample was obtained. Peak melting temperature (Tm) and sharpness of DSC peak of the stepwise annealing sample increased with the annealing step. A high melting‐temperature sample was obtained in a short time, and Tm increased up to 238.5°C which is higher than all the Tm values that appear in the literature. The long period calculated from SAXS curves of the stepwise annealing sample increased with the annealing step. The increase of crystallite size and perfection of the crystal in the stepwise annealing process is suggested. Annealing experiment indicated that T°m should be higher than about 235°C. Tm increased linearly with the annealing temperature of the final step in the stepwise annealing (Ta). The equilibrium melting temperature (T°m) for PBT was estimated to be 247°C by the application of a Hoffman–Weeks plot to the relation between Tm vs. Ta. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 2420–2429, 1999 相似文献