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21.
Yoshiyuki Mizuhata Nobuhiro Takeda Norihiro Tokitoh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4-5):947-948
The reductive debromination of an very crowded bis(bromodiaryl- silyl)butadiyne 2 was performed with potassium graphite to give the corresponding 2-allenyl-1-benzosilole 3 was isolated as a main product. 相似文献
22.
23.
Dr. Tatsuya Yanagisawa Prof. Dr. Yoshiyuki Mizuhata Prof. Dr. Norihiro Tokitoh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(44):11273-11278
The reversible addition of olefins to a phosphanylalumane, P−Al single-bond species, was investigated. The P−Al bond added to ethylene and relatively small terminal alkenes (propylene and hex-1-ene) at room temperature to give the corresponding alkene adducts. Heating the terminal alkene adducts released the corresponding alkenes and regenerated the P−Al bond, but no release of ethylene was observed even under vacuum conditions. The reactivity of ethylene adduct as a new saturated C2 vicinal P/Al-based FLP was also investigated. The ethylene adduct was found to undergo complexation with nitriles to give the corresponding nitrile adducts to the Al center, which retained the ethylene tether as in the case of the corresponding P/B-based FLP. However, the reactivity of ethylene toward CO2 and benzaldehyde differed from that of the P/B system giving the corresponding adducts. 相似文献
24.
Shinji Ejiri Sinya Aoki Tetsuo Hatsuda Kazuyuki Kanaya Yoshiyuki Nakagawa Hiroshi Ohno Hana Saito Takashi Umeda 《Central European Journal of Physics》2012,10(6):1322-1325
We study the QCD phase structure at high temperature and density adopting a histogram method. Because the quark determinant is complex at finite density, the Monte-Carlo method cannot be applied directly. We use a reweighting method and try to solve the problems which arise in the reweighting method, i.e. the sign problem and the overlap problem. We discuss the chemical potential dependence of the probability distribution function in the heavy quark mass region and examine the applicability of the approach in the light quark region. 相似文献
25.
Shofu Matsuda Yuuki Okuda Yoshiki Obu Norio Nagayama Minoru Umeda 《Electroanalysis》2019,31(12):2466-2471
With the objective of understanding the kinetic redox properties of triphenylamine derivatives in association with chemical reactions, for their future application in functional organic semiconductor devices, the electrochemical characteristics of 4‐(2,2‐diphenylethenyl)‐N,N‐bis(4‐methylphenyl)‐benzenamine (TPA) were evaluated. Based on cyclic voltammograms of TPA on Pt disk electrodes with diameters of 300 μm and 10 μm at slow and fast scan rates in an acetonitrile solution, the TPA.+ is stable, while the TPA2+ is unstable. Importantly, the unstable TPA2+ appears to break down by a subsequent chemical reaction. A Cottrell plot analysis from chronoamperometry of a solution containing TPA reveals that both the first and second oxidations are one‐electron reactions. Concerning the stabilization mechanism of the first oxidation state of TPA, the results of molecular orbital calculations indicate that the electrons of the HOMO level are distributed in the triphenylamine group, which induces a resonance‐stabilized TPA.+. Based on these results, TPA/TPA.+ is suggested to have a sufficient stability for further application in organic semiconductor devices. 相似文献
26.
The new tripeptide reported here is composed of (R)-2-(3-aminophenoxy)propionic acid and is a bowl-shaped receptor that simultaneously binds both cations and anions of acetylcholine chloride and benzyltrimethylammonium compounds. An intriguing conformational change of the host was observed in the complexation of the ionic pair, where anion-induced flipping of the amide group on the macrocycle occurred. 相似文献
27.
28.
Nobuhiro Takeda Norihiro Tokitoh Renji Okazaki 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):633-636
The first rotational isomers of stable selenoaldehydes are synthesized by deselenation of cyclic polyselenides having an efficient steric protection group, 2, 4, 6-tris[bis(trimetylsilyl)methyl]phenyl (Tbt). Reactions of these selenoaldehydes with W(CO)5.THF gives the corresponding η1-selenoaldehyde tungsten complexes, the structures of which are established by X-ray crystallography. 相似文献
29.
Toyoji Kakuchi Toshifumi Satoh Junji Mata Satoshi Umeda Hisaho Hashimoto Kazuaki Yokota 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(3):325-336
Abstract The cyclopolymerizations of 1,2:5,6-dianhydro-3,4-di-O-pentyl-D-mannitol (1b) and 1,2:5,6-dianhydro-3,4-di-O-decyl-D-mannitol (1c) were carried out using BF3OEt2 and t-BuOK. All the resulting polymers consisted of cyclic constitutional units, i.e., the extent of cyclization was 100%. The polymer structures for the polymerization with t-BuOK were (1→6)-2,5-anhydro-3,4-di-O-pentyl-D-glucitol (2b) and (1→6)-2,5-anhydro-3,4-di-O-decyl-D-glucitol (2c), whereas those with BF3O-decyl2 comprised 2,5-anhydro-D-glucitols as major units along with other cyclic ones. These polymers were soluble in n-hexane, CHCl3, and THF, but insoluble in water, which differs from the amphiphilic solubility of (1→6)-2,5-anhydro-3,4-di-O-methyl-D-glucitol (2a). The cation-binding properties of 2b and 2c were examined using alkali-metal picrates in order to compare them with those of 2a. The extraction yields for each cation decreased in the order of 2c < 2b < 2a. Every polymer exhibited a similar cation-binding selectivity in the order Cs+ > Rb+ > K+ ? Na+ > Li+. The ratio of K+ and Na+, K+/Na+, was 4.6 for 2a, 5.1 for 2b, and 7.1 for 2c in the increasing order 2a < 2b > 2c. 相似文献
30.
Yoshiaki Miyamoto Norihiro Wada Dr. Takahiro Soeta Dr. Shuhei Fujinami Prof. Dr. Katsuhiko Inomata Prof. Dr. Yutaka Ukaji 《化学:亚洲杂志》2013,8(4):824-831
The stereoselective direct transformation of N‐(propargylic)hydroxylamines into cis‐2‐acylaziridines was achieved by the combined use of AgBF4 and CuCl. Copper salts were found to promote the transformation of the intermediary 4‐isoxazolines into 2‐acylaziridines and both 3‐aryl‐ and 3‐alkyl‐substituted 2‐acylaziridines could be prepared by using this method. Furthermore, subsequent 1,3‐dipolar cycloaddition of azomethine ylides that were generated in situ from the intermediary 2‐acylaziridines with maleimides was achieved in a stereoselective one‐pot procedure to afford the corresponding 2‐acylpyrrolidines, which consisted of an octahydropyrrolo[3,4‐c]pyrrole skeleton. 相似文献