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101.
102.
Simon Rohrbach Andrew J. Smith Jia Hao Pang Darren L. Poole Tell Tuttle Shunsuke Chiba John A. Murphy 《Angewandte Chemie (International ed. in English)》2019,58(46):16368-16388
Recent developments in experimental and computational chemistry have identified a rapidly growing class of nucleophilic aromatic substitutions that proceed by concerted (cSNAr) rather than classical, two‐step, SNAr mechanisms. Whereas traditional SNAr reactions require substantial activation of the aromatic ring by electron‐withdrawing substituents, such activating groups are not mandatory in the concerted pathways. 相似文献
103.
104.
α-Methylene-β-lactams 3 were synthesized from the various 2-bromoallylamine derivatives 2 using a catalytic amount of Pd(OAc)2 or PD(acac)2 and PPh3, under 1–4 atom pressure of CO in good yields. Similarly, α-alkylidene-β-lactams 20 were synthesized from 3-alkyl-2-bromoallylamines 19, which were easily prepared from the olefins 14, in the same manner. 相似文献
105.
106.
The oxygen ion conductivity of Y2O3---Nb2O5 with a fluorite-like structure was studied. Substitutional solid solutions of Nb2 O5 in Y2O3 lattice formed the defect fluorite phase and remarkably enhanced the oxygen ion conductivity. Doping with tetravalent cations, especially Ti4+ or Ce4+, in yttria-niobia oxide is effective in enhancing the oxygen ion conductivity. Although the n-type semiconducting property appeared below PO2 = 10−18 atm at 1243 K, the yttria-niobia mixed oxide doped with Ce4+, Ti4+, and Zr4+ stably exhibited oxygen-ion conduction in the wide range of oxygen partial pressures studied. 相似文献
107.
108.
Ultrafine particles (UFP) of six kinds of FeNi alloys were synthesized by the method of hydrogen plasma reaction. The prepared UFP samples were examined by X-ray diffraction, electron transmission microscopy and magnetic measurement. The spherical FeNi UFP alloys with a mean particle size less than 35 nm can be prepared with a production rate much higher than by conventional methods. The phase constitution of UFP alloys is different from the equilibrium phase diagram owing to rapid condensation of evaporated metal gases. Although the magnetization for the UFP alloys has almost the same temperature dependence as that of the bulk alloys, the saturation magnetization remarkably decreases as the bulk alloys change into the UFP alloys. 相似文献
109.
110.
Abe K Amako K Arai Y Asano Y Chiba M Chiba Y Daigo M Emura T Endo I Fukawa M Fukui T Fukushima Y Haba J Haidt D Hayashibara I Hemmi Y Higuchi M Hirose T Hojyo Y Homma Y Hoshi Y Ikegami Y Ishihara N Kamitani T Kanematsu N Kanzaki J Kikuchi R Kondo T Koseki T Kubo K Kurashige H Matsui T Minami M Miyake K Mori S Nagashima Y Nakamura T Nakano I Odaka S Ogawa K Ohama T Ohsugi T Ono A Osabe H Saito H Sakae H Sakamoto H Sakamoto S Sakano M Sakuda M Sasao N Sato M Shioden M Shirai J Suekane F 《Physical review letters》1988,61(8):915-918