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101.
102.
Synthesis, characterization, and catalytic reactivity of a highly basic macrotricyclic aminopyridine
Uchida N Taketoshi A Kuwabara J Yamamoto T Inoue Y Watanabe Y Kanbara T 《Organic letters》2010,12(22):5242-5245
The synthesis methods, physicochemical and structural characteristics, and catalytic reactivity of new macrocyclic proton chelators, N,N',N'-tris(p-tolyl)azacalix[3](2,6)(4-pyrrolidinopyridine) and N,N',N'-tris(p-tolyl)azacalix[3](2,6)(4-piperidinopyridine), are studied. The introduction of pyrrolidino and piperidino groups into the pyridine unit enables the enhancement of the synergistic proton affinity of the cavity of the macrotricycle giving a high basicity (pK(BH+) = 28.1 and 27.1 in CD(3)CN), resulting in a catalytic activity for the Michael addition of nitromethane with α,β-unsaturated carbonyl compounds. 相似文献
103.
Wakabayashi R Kubo Y Kaneko K Takeuchi M Shinkai S 《Journal of the American Chemical Society》2006,128(27):8744-8745
The ordered structures constructed from an aligner molecule 1o and conjugated polymers (CPs) were efficiently converted into the poly-pseudo-rotaxane structures by the template-assisted ring-closing olefin metathesis (RCM) of olefinic groups at the peripheral positions of 1o. Moreover, the poly-pseudo-rotaxane structures permitted the separation of the crystalline ordered assemblies of CP by size exclusion chromatography and the preservation of the sheet morphologies after the treatment with trifluoroacetic acid. The morphologies and the periodicities of assemblies were also maintained after the retrieving treatments. 相似文献
104.
We introduce an algebraic formulation of the cyclic sum formulas for multiple zeta values and for multiple zeta-star values. We also present an algebraic proof of cyclic sum formulas for multiple zeta values and for multiple zeta-star values by reducing them to Kawashima's relation. 相似文献
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107.
The purpose of the present study was to determine the proteins that bind to acetophenones in the liver. Immobilized p-hydroxyacetophenone (p-HAP) was used as a ligand of affinity chromatography. Analysis using sodium dodesyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that five polypeptides in the liver cytosolic fraction specifically bound to the p-HAP matrix. These polypeptides were digested with Lys-specific protease and used to generate peptide maps by reversed-phase high-performance liquid chromatography. Consequently, identification from a data base of protein sequences revealed that the five polypeptides were glycogen phosphorylase, cytosolic aldehyde dehydrogenase, adenosine kinase, class I alcohol dehydrogenase and glutathione S-transferase A2. In addition to p-HAP, acetylsalicylic acid also displayed a prominent ability to elute these five enzymes from the p-HAP affinity column loaded with the cytosolic fraction of the liver. Thus, p-HAP has affinities to the above liver enzymes and is a useful ligand for analysis of them. 相似文献
108.
Okamoto K Matsuoka Y Wakabayashi N Yamagishi A Hoshino N 《Chemical communications (Cambridge, England)》2002,(3):282-283
A novel amphiphilic Ru(II) complex, [Ru(acac)2L] (acac = acetylacetonato, L = 5,5'-bis(4-octylphenyloxycarbonyl)-2,2'-bipyridyl), in which L undergoes SmC, SmA and N liquid crystal phases, exhibits a remarkable chirality effect on its monolayer state: that is, a racemic mixture gives a monolayer consisting of spike-like aggregates of 1.2 nm (in height) x 50 nm (in diameter), whereas the delta-enantiomer gives a uniform monolayer. 相似文献
109.
Wakabayashi N Takeichi M Uchida H Watanabe M 《The journal of physical chemistry. B》2005,109(12):5836-5841
Oxygen reduction reaction (ORR) activity and H(2)O(2) formation at Pt(54)Fe(46), Pt(68)Co(32), and Pt(63)Ni(37) electrodes in 0.1 M HClO(4) solution at 20 to 90 degrees C were investigated by using a channel flow double electrode method. In the temperature range of 20-50 degrees C, the apparent rate constants k(app) for ORR at these electrodes were found to be 2.4-4.0 times larger than that at a pure Pt electrode, whereas their apparent activation energies of 41 kJ mol(-1) at -0.525 V vs E degrees (0.760 V vs RHE at 30 degrees C) were comparable to that at the Pt electrode. H(2)O(2) yield was ca. 1.0% at Pt(54)Fe(46) and ca. 0.16% at Pt(68)Co(32) and Pt(63)Ni(37) between 0.3 and 1.0 V vs RHE. The k(app) values at the alloy electrodes decreased with elevating temperature above 60 degrees C, and settled to almost the same values at the Pt electrode. The H(2)O(2) production was not detected at the alloy electrodes once heated at the high temperature in the solution, probably due to the thickening of the Pt skin-layer by a considerable dissolution of nonprecious metal components (Fe, Co, Ni) from the alloys. 相似文献
110.
Kazunari Domen Junko N. Kondo Fumitaka Wakabayashi 《Research on Chemical Intermediates》1998,24(4):411-423
Adsorption of linear olefins (C2?C4) on a deuterated H-ZSM-5 (D-ZSM-5) was studied by infrared (IR) spectroscopy. The initial interaction of the olefins with Brønsted acidic OD groups was hydrogen-bonding to form π-complexes at low temperatures. The adsorbed ethene and propene desorbed by heating under evacuation, while various reactions took place for adsorbed 1-butene; double bond migration (DBM) to 2-butene below 230 K followed by dimerization at room temperature. An unusual reaction path was deduced for DBM of 1-butene, where proton transfer from Brønsted acid sites (BAS) to the adsorbed 1-butene was not essential. 相似文献