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排序方式: 共有124条查询结果,搜索用时 15 毫秒
91.
92.
Hiroya Takada Kouichi Ohe Sakae Uemura 《Angewandte Chemie (International ed. in English)》1999,38(9):1288-1289
Up to 99 % de is obtained in the imidation of diaryl sulfides bearing a chiral oxazolinyl moiety at the ortho position. The corresponding N-p-tosylsulfimides are produced upon use of chloramine T trihydrate in the presence of Cu(OTf)2 as catalyst [Eq. (1)]. OTf=trifluoromethanesulfonate; Ts=toluenesulfonyl. 相似文献
93.
94.
Hiroya Ito 《Journal of Elasticity》1990,24(1-3):43-78
We are concerned with the coerciveness of the strain energy E(u) (in linear elasticity) associated with a displacement vector u on the Sobolev space H1 () or its subspaces, a domain in n representing an isotropic elastic body—certain specific cases are called Korn's inequalities. Sufficient (and necessary) conditions on the Lamé moduli for E(·) to be coercive (or uniformly positive) on such spaces are given, and the associated best possible constants are obtained for some cases. 相似文献
95.
Mild and efficient cyclization reaction of 2-ethynylaniline derivatives to indoles in aqueous medium
Results of the optimized cyclization reaction of 2-ethynylaniline derivatives to indoles catalyzed by copper(II) salts are described. The reactions can be carried out in a mixture of H2O and MeOH in the presence of 1-ethylpiperidine at room temperature. These conditions can be applied to a bulky substrate, which is difficult to be cyclized efficiently by existing reaction conditions. Furthermore, this reaction condition was applied to a catalyst recycling reaction system. 相似文献
96.
Shin'ichiro Asayama Hideo Ogawa Takashi Noguchi Kazuji Suzuki Hiroya Andoh Akira Mizuno 《International Journal of Infrared and Millimeter Waves》2004,25(1):107-117
We have developed an integrated sideband-separating SIS mixer for the 100 GHz band based on the waveguide split block. The measured receiver noise temperatures with 4.0–8.0 GHz IF are less than 60 K in the LO frequency range of 90–110 GHz, and a minimum value of around 45 K is achieved at 100 GHz. The image rejection ratios are more than 10 dB in the frequency range of 90–110 GHz. We have installed the sideband-separating SIS mixer into an atmospheric ozone-measuring system at Osaka Prefecture University and successfully observed an ozone spectrum at 110 GHz in SSB mode. This experimental result indicates that the sideband-separating SIS mixer is very useful for astronomical observation as well as atmospheric observation. 相似文献
97.
A Spin‐Active,Electrochromic, Solvent‐Free Molecular Liquid Based on Double‐Decker Lutetium Phthalocyanine Bearing Long Branched Alkyl Chains 下载免费PDF全文
Agnieszka Zielinska Dr. Atsuro Takai Dr. Hiroya Sakurai Dr. Akinori Saeki Dr. Marcin Leonowicz Dr. Takashi Nakanishi 《化学:亚洲杂志》2018,13(7):770-774
Synthesis and characterization of a novel, multifunctional, solvent‐free room‐temperature liquid based on alkylated double‐decker lutetium(III) phthalocyanine (Pc2Lu) are described. Lowering of the melting point and viscosity of intrinsically solid Pc2Lu compounds has been achieved through the attachment of flexible, bulky, and long branched‐alkyl chains, that is, thio‐2‐octyldodecyl, to the periphery of the Pc2Lu unit. The embedded Pc2Lu unit maintains its inherent molecular functions, such as spin‐active nature and electrochromic behavior in the liquid state. Comparison of the properties with a solid‐like Pc2Lu derivative, functionalized with shorter alkyl chains, that is, thio‐2‐ethylhexyl, underlines the importance of the hampering effect on the π–π interactions of neighboring Pc2Lu molecules by bulkier and longer branched‐alkyl chains. This study could possibly pave the way for novel multifunctional liquids whose spin‐activities are associated with their rheological or optoelectronic properties. 相似文献
98.
A new fluorescent ionophore for alkaline earth metal ions, 4'-(9-fluorenecarboxamido)benzo-15-crown-5 (3), was synthesized; its photochemical behavior was investigated using UV, fluorescence, (1)H NMR, and (13)C NMR spectrometry. In the absence of a metal ion, the fluorene moiety showed weak fluorescence emission (fluorescence "Off" state). However, complexation with metal ions greatly enhanced the fluorescence intensity (fluorescence "On" state). 相似文献
99.
A method for the catalytic C-H activation of hydrazone compounds followed by intramolecular amination is described. It requires the use of a catalytic amount of Pd(OAc)2 in the presence of Cu(OAc)2 and AgOCOCF3, which efficiently effects the cyclization to afford variously substituted indazoles. The reactions proceed under relatively mild conditions and thus tolerate a variety of functional groups, including alkoxycarbonyl and cyano groups and halogen atoms. 相似文献
100.
Tetsuya MiyoshiShohei Sato Hiroya TanakaChihiro Hasegawa Masafumi UedaOkiko Miyata 《Tetrahedron letters》2012,53(32):4188-4191
The efficient one-pot umpolung α-phenylation of ketones via N-alkenylisoxazolidine is described. When the various ketones are treated with triphenylaluminum prepared from phenylmagnesium chloride and AlCl3 in the presence of isoxazolidine, the desired products are obtained in good to moderate yield. This method is equivalent to a direct α-arylation reaction of carbonyl groups. 相似文献