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141.
Kentaro Yachi Hiroshi Shinokubo Koichiro Oshima 《Angewandte Chemie (International ed. in English)》1998,37(18):2515-2517
The one-pot synthesis of cyclopropyl compounds from 1-alkynes has been achieved by direct cyclopropanation of a 1-alkenylzinc species upon treatment with iodomethylzinc and trapping of the cyclopropylzinc intermediate with allyl bromide in the presence of CuCN⋅2 LiCl (see reaction scheme). This method proceeds under mild conditions and in good yield. 相似文献
142.
Masashi Kaji Kazuhiko Nakahara Koichiro Ogami Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》1999,37(19):3687-3693
A new type of epoxy resin containing 4,4′-diphenylether moiety in the backbone (2) was synthesized, and was confirmed by gel permeation chromatography, infrared spectroscopy, and 1H nuclear magnetic resonance spectroscopy. In addition, in order to evaluate the influence of 4,4′-diphenylether moiety in the structure, epoxy resins having 4,4′-biphenylene moiety (4) and having 1,4-phenylene moiety (6) in place of 4,4′-diphenylether moiety were synthesized. The cured polymer obtained through the curing reaction between the new diphenylether-containing epoxy resin and phenol novolac was used for making a comparison of its thermal and physical properties with those obtained from 4, 6, and bisphenol-A (4,4′-isopropylidenediphenol) type epoxy resin. The cured polymer obtained from 2 showed markedly higher anaerobic char yield at 700°C of 44.0 wt %, higher fracture toughness, and higher mechanical strength and modulus. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3687–3693, 1999 相似文献
143.
Treatment of secondary or tertiary alkyl bromides with alkyl Grignard reagents in the presence of catalytic amounts of silver bromide and potassium fluoride in CH2Cl2 afforded the corresponding cross-coupling products in reasonable yields. Moreover, silver showed catalytic activity for the cross-coupling reactions of alkyl bromides with aryl Grignard reagents. 相似文献
144.
Hayashi S Hirano K Yorimitsu H Oshima K 《Journal of the American Chemical Society》2006,128(7):2210-2211
Treatment of tertiary homoallyl alcohol with aryl halide under palladium catalysis resulted in the transfer of the allyl moiety of the homoallyl alcohol to aryl halide and yielded the corresponding cross-coupling product stereo- and regiospecifically. The transfer process includes retro-allylation, which proceeds via a conformationally regulated six-membered transition state. The retro-allylation can be regarded as a method for the stereo- and regiospecific preparation of sigma-allylpalladium. 相似文献
145.
Taking advantage of a radical-based methodology, mild and chemoselective phosphination reactions of organic halide and alkyl imidazole-1-carbothioates have been developed. The mild reaction conditions allow labile functional groups to survive during the reaction. 相似文献
146.
147.
Yasuhiro Masuda Koichiro Asahi Kichiji Hatanaka Sun-Chan Jeong Shinsuke Kawasaki Ryohei Matsumiya Kensaku Matsuta Mototsugu Mihara Yutaka Watanabe 《Physics letters. A》2012
A neutron EDM measurement with a comagnetometer is discussed. For magnetometry, polarized xenon atoms are injected into a cylindrical cell where a cylindrically symmetric magnetic field and an electric field are applied for the EDM measurement. The geometric phase effect (GPE), which originates from particle motion in a magnetic field gradient, is analyzed in terms of the Dyson series. The motion of the xenon atom is largely suppressed because of a small mean free path. The field gradient is controlled by means of NMR measurements, where the false effect of Earth?s rotation is removed. As a result, the GPE is reduced below 10−28e cm. 相似文献
148.
Uchida T Sekine Y Matsui T Ikeda-Saito M Ishimori K 《Chemical communications (Cambridge, England)》2012,48(53):6741-6743
HutZ, one of the crucial proteins of the iron uptake system in Vibrio cholerae, was purified, which binds to heme at a stoichiometry of 1 : 1. In the presence of ascorbic acid, the HutZ-bound heme degrades via the same intermediates observed in heme oxygenase, suggesting that HutZ works as a heme degradation enzyme. 相似文献
149.
Near-infrared fluorescent silica-porphyrin hybrid nanotubes (HNTs) were successfully synthesized by π-π stacking, electrostatic interaction and a sol-gel reaction. The HNTs-labeled macrophages were detected in vivo, and the minimum detectable number of cells was 200. Furthermore, the biodistribution of HNTs-labeled macrophages was tracked by fluorescence imaging. 相似文献
150.
Tadashi Wadayama Toru Hada Koichiro Wakasugi Masao Kasahara 《Designs, Codes and Cryptography》2001,23(1):23-34
The paper presents lower and upper bounds on the maximumnonlinearity for an n-input m-output Booleanfunction. We show a systematic construction method for a highlynonlinear Boolean function based on binary linear codes whichcontain the first order Reed-Muller code as a subcode. We alsopresent a method to prove the nonexistence of some nonlinearBoolean functions by using nonexistence results on binary linearcodes. Such construction and nonexistence results can be regardedas lower and upper bounds on the maximum nonlinearity. For somen and m, these bounds are tighter than theconventional bounds. The techniques employed here indicate astrong connection between binary linear codes and nonlinear n-input m-output Boolean functions. 相似文献