Nara-shi, Japan

Nara University of Education is a national university at Nara, Nara, Japan. The predecessor of the school was founded in 1888, and it was chartered as a university in 1949. Wikipedia.


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Yamabe S.,Nara University of Education | Fukuda T.,Nara University of Education | Ishii M.,Nara University of Education
Theoretical Chemistry Accounts | Year: 2011

Acid-catalyzed ester hydrolyses were studied by means of DFT calculations. A model composed of ester and H3O+(H2O)15 was adopted, and substrates esters are ethyl acetate, ethyl para-X-substituted benzoates (X = O2N, Cl, H, iso-Bu, MeO, and Me2N), and isobutyl benzoate. For the ethyl acetate, a stepwise path, precursor → TS1 → Int1 → Int2 → TS2 → product, was obtained. Here, TS is the transition state, and Int is the tetrahedral intermediate. The path is somewhat different from the established AAC2 mechanism; the carbocation intermediate was calculated to be absent in the present model. The absence holds even for benzoates that may stabilize the cation except the X = Me2N substituted one. At each local energy minimum, the cation character is retained in H3O+. Proton relays along hydrogen bonds were found to prompt interchanges of covalent bonds. The rate-determining step is either TS1 for the electron-withdrawing X or TS2 for the electron-donating one. © 2011 Springer-Verlag.


Yamabe S.,Nara University of Education | Kawagishi N.,Nara University of Education
Theoretical Chemistry Accounts | Year: 2011

Calculations at the B3LYP/6-311+G**, MPW1K/6-311+G**, and MP2/6-311+G** level theory were carried out for the CO2 + nH2O → H2CO3 + (n - 1)H2O chemical reaction, where n denotes the number of water molecules. For n = 1, 2, 3, and 4 water molecules, a concerted path (without intermediates) for the formation of H2CO3 was obtained. For n = 6(3 + 3) and n = 8(4 + 4) water molecules, the MPW1K and B3LYP/6-311+G** SCRF = PCM methods resulted in an ion-pair intermediate being formed. Here, +3 or +4 stands for the three or four catalytic water molecules. The catalytic water molecules are distinguished from the reaction participating ones (either three or four). For n = 3 + 5 and n = 3 + 10, two ion-pair intermediates were obtained using both the B3LYP and MPW1K DFT methods. In order to check the method and model dependence, furthermore, n = 3 + 17 and n = 3 + 27 reacting systems were examined. Here, a likely mechanism of formation and electrolytic dissociation of carbonic acid was found. First, the O2C-OH2 complex is formed. Second, it is isomerized to the Zundel cation H5O2 +. Third, the cation is converted to the carbonic acid. The isomerization, i. e., proton transfer, was computed to occur along the hydrogen-bonded network of the pentagon shape. © 2011 Springer-Verlag.


Yamabe S.,Nara University of Education | Yamazaki S.,Nara University of Education
Theoretical Chemistry Accounts | Year: 2011

Paths of the Kolbe-Schmitt reaction were investigated by the use of RB3LYP/6-311(+)G(d,p) density functional theory calculations. In a monomer model composed of C6H5O-, Na+ and CO2 affording sodium salicylate [C6H4(OH)CO2 -Na+], a proton-shift step (Z Naturforsch 57a:812, 2002) was found to have an unrealistically large activation energy. In consideration of the phenol volatilization in the Kolbe's experiment and the need of the linearity of the proton-transfer path, a dimer model was constructed. Again, a mutual proton-transfer step has a large activation energy. Alternatively, in a dimer model, a transfer path where the phenoxide ion in one monomer acts as a proton acceptor was found to have a reasonable energy. Addition of one more sodium ion leads to the significant lowering of activation energies. Thus, in the dimer, two monomers behave differently (A + A → A + B); one is as if it were a catalyst. © 2010 Springer-Verlag.


Yamazaki S.,Nara University of Education
Yuki Gosei Kagaku Kyokaishi/Journal of Synthetic Organic Chemistry | Year: 2014

The development of new efficient bond-forming reactions is important in synthetic organic chemistry. Recent developments concerning the synthetic methods utilizing highly electrophilic Michael acceptors, ethenetricarboxylates are described. Ethenetricarboxylate is a member of methylenemalonates and more reactive than alkylidenemalonates by the electron-withdrawing effect of 2-ester group. In particular, Lewis acids promote the reactions of ethenetricarboxylate derivatives efficiently. Various nucleophiles could undergo conjugate additions and the further bond-forming reactions. The high functionalization of the products may be useful for further elaboration. This paper describes catalytic Friedel-Crafts/Michael addition reactions of indoles, conjugate addition of amines, and various cycloadditions with compounds such as propargyl amines/ alcohols, aminobenzaldehydes, and allenes in the presence of Lewis acid to give nitrogen and oxygen-containing heterocyclic and carbocyclic compounds. One-pot reactions with compounds such as aminoalcohol and Huisgen zwitterion in the absence of Lewis acids lead to various heterocyclic compounds. Lewis acid-promoted intramolecular cyclization reactions of functionalized ethenetricarboxylate derivatives has also been described.


This paper results from combining Electron Spin Resonance (ESR) spectroscopy and atom transfer radical polymerization (ATRP) to study the basic chemistry of radical polymerizations. This combination of analytical and controlled preparation techniques can provide information on chain length of propagating radicals and chain transfer reactions to polymers which has been previously difficult or impossible to study by direct detection of radicals in radical polymerizations by ESR. Two results are obtained by the ESR/ATRP combination technique. The first provides an estimation of the effect of chain length on the structure of methacrylate propagating radicals, especially in the initial stage of radical polymerizations. Model radical precursors of dimeric, trimeric, tetrameric, and pentameric structures of tBMA and MMA were prepared by ATRP. The corresponding model radicals were generated from these precursors and were observed by ESR at various temperatures. The ESR spectra provided direct information on chain length dependent changes of the averaged structures at the chain ends of the model propagating radicals, indicating that distortion in dihedral angles between chain end pπ-orbital and Cβ-H bonds increased with increasing chain length. The second result provides information on the radical migration reactions during the polymerization of acrylates. Radical precursors of ethyl-, n-butyl-, and dodecyl acrylates with various chain lengths (DP = 10, 25, 60, etc.) were prepared by ATRP. Model propagating radicals were generated from these precursors and were observed by ESR at various temperatures. These radicals showed chain length dependent spectroscopic change due to radical migration reactions from model propagating to mid-chain radicals with increasing temperature. Longer chained radicals with the same ester side groups showed easier formation of mid-chain radicals. An examination of side group dependency indicated that, longer alkyl side groups showed easier radical migration reactions. The development of ATRP enabled us to resolve these problems associated with side reactions in radical polymerizations. © 2015 Elsevier Ltd.


Toyota H.,Nara University of Education
Perceptual and Motor Skills | Year: 2015

The relationship between the criterion for choosing and the selfchoice eff ects (greater recall in a self-choice compared to a forced-choice condition) on intentional memory was examined. Thirty-three female nursing school volunteers were administered 24 word pairs in a 2 × 2 design to assess the infl uence of motivation upon free recall. When word pairs were presented to participants, they were asked to choose a word to-be-remembered, either in a self-choice condition or a forced-choice condition. Words chosen by the participants were recalled more often than those chosen by the experimenter (forced choice). Thus, the self-choice eff ect was greater for words chosen with a self-reference criterion compared to a metamemory criterion, supporting the integration hypothesis as the origin of the self-choice effect. © Perceptual & Motor Skills 2015.


Yamazaki S.,Nara University of Education
Heterocycles | Year: 2016

The synthesis of heterocyclic compounds utilizing highly electrophilic ethenetricarboxylates is described. Ethenetricarboxylate is a member of methylenemalonates and more reactive than frequently used alkylidenemalonates by the electron-withdrawing effect of 2-carboxyl group. They are utilized as efficient Michael acceptors or electron-deficient C=C components. Lewis acids also promote the reactions of ethenetricarboxylate derivatives efficiently.sThe intermolecular and intramolecular reactions of ethenetricarboxylates towards synthesis of heterocycles are presented. © 2016 The Japan Institute of Heterocyclic Chemistry.


Yamazaki S.,Nara University of Education | Takebayashi M.,Nara University of Education | Miyazaki K.,Nara University of Education
Journal of Organic Chemistry | Year: 2010

(Graph Presented) Quinolines are an important class of compounds, and the development of new efficient synthetic strategies for the construction of quinolines is of considerable interest. Zinc triflate catalyzed cyclization of ethenetricarboxylate derivatives with 2-aminobenzaldehydes has been examined. The reaction of ethenetricarboxylate with 2-aminobenzaldehydes in the presence of zinc triflate (0.2 equiv) at 80 °C in ClCH2CH2Cl gave bridged tetrahydroquinoline derivatives in 15-95% yield. On the other hand, the reaction at room temperature in CH2Cl2 gave hydroxy tetrahydroquinoline derivatives in 38-90% yield. Heating the hydroxy tetrahydroquinolines with zinc triflate (0.2 equiv) at 80 °C in ClCH 2CH2Cl led to the bridged tetrahydroquinoline derivatives in 75-96% yield. Thermal reaction of the bridged tetrahydroquinolines (180 °C) gave indole derivatives regioselectively. © 2010 American Chemical Society.


Deguchi T.,Nara University of Education
Social Science Computer Review | Year: 2014

A computer simulation based on both game theory and the cellular automaton model was conducted to investigate the effects of individuals' interactions and certain conditions on the spread of rule-breaking behavior in public places. Four decision matrices representing obedient, deviant, conforming, and contrary principles were prepared experimentally. The ratio of these principles ranged from 1:2:3:4 to 4:3:2:1 (obedient:deviant:conforming:contrary). There were a total of 24 data sets with each data set composed of 10 decision matrices. In addition to these 24 data sets, the ratio 1:1:1:1 was prepared. This data set was composed of four decision matrices. The results indicated that rule-breaking behavior spreads under the following conditions: (A) when people act according to both individual factors (e.g., their attitudes) and situational factors (e.g., their neighbors' behavior); (B) when there are more deviant people than obedient people; (C) when the intensity of rule-breaking behavior is higher than that of rule-obeying behavior. Condition A is an important factor. If conditions B or C are satisfied, the spread of rule-breaking behavior does not occur necessarily. At a certain probability threshold, rule-breaking behavior spreads sharply when people act based on individual factors (e.g., their attitudes); the spread of such behavior cannot be attributed solely to situational factors (e.g., neighbors' behavior). There is only a fine line between rule breaking and obeying near the probability threshold. © The Author(s) 2013.


Yamabe S.,Nara University of Education | Yamazaki S.,Nara University of Education
Journal of Physical Organic Chemistry | Year: 2011

The title reactions were studied by means of the density functional theory calculations. A base promoted reaction (called here 'B') was traced in a model composed of benzaldehyde, malononitrile, and (H2O)11. A neutral model ('N') of Ph-CHO, H2C(CN)2 and (H 2O)12 was also examined in line with a reported clean reaction. It was found that the ion pair of HC(CN)2 - and H3O+ is generated at the first step for N. For B, there are five elementary processes, and for N, four ones were obtained. By RB3LY/6-311 + G* SCRF = PCM//RB3LYP/6-31(+)G* energy calculations, the rate determining steps for both B and N reactions are the second proton removal, TS5(B) and TS3(N), respectively. In both B and N, the neutral species Ph(HO)HC-CH(CN)2 is the key intermediate. © 2010 John Wiley & Sons, Ltd.

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