| Project/Area Number |
17550103
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Synthetic chemistry
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| Research Institution | Nara University of Education |
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Principal Investigator |
YAMABE Shinichi Nara University of Education, Faculty of Education, Professor, 教育学部, 教授 (00109117)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAZAKI Shoko Nara University of Education, Faculty of Education, Professor, 教育学部, 教授 (50182481)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2006: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2005: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | Organic chemistry / Reaction mechanism / Computational chemistry / Friedel-Crafts Reaction / Density functional theory / Disilene / Hydrogen bond / 水素1,5-シフト / Beckmann転位 / ベンジル-ベンジル酸転位 / 芳香族求電子置換反応 / エナンチオ選択的付加 |
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| Research Abstract |
1) The Friedel-Crafts reaction is a representative electrophilic aromatic substitution reaction, catalyzed by Lewis acids. The precise reaction mechanism has not been elucidated yet. Understanding of catalytic ability of the bridged form of a typical Lewis acid Al_2Cl_6, the driving force for proton elimination of Wheland intermediate, and rate-determining step is required. B3LYP density functional theory calculations with 6-31G^* basis set of Friedel-Crafts aclylation reaction of benzene with acetyl chloride catalyzed by aluminum chloride were carried out. At first, carbonyl oxygen coordinates to Al and the resulting complex isomerizes to acylium ion intermediate (π-complex). After the electrophilic addition, Wheland intermediate (σ-complex) forms. Thus, the elementary process was elucidated. The study on Friedel-Crafts alkylation is currently under investigation.
2) Density functional and ONIOM calculations of alcohol and phenol additions to two (tetramethyl and tetramesityl) dislenes were carried out. The dimer of MeOH adds to Me_2Si = SiMe_2 more readily than the monomer. The trimer gives not the adduct but a zwitter-ionic intermediate. In the (CF_3OH)_2 addition to Me_2Si = SiMe_2, the H......Si bond formation is more advanced than the O....Si bond formation at the transition state (TS). Additions of seven phenol derivatives to Me_2Si = SiMe_2 were examined, and the dimer reactions were found to be better than the monomer reaction regardless of the substituents on benzene rings. (MeOH)_2 reacts also with Mes_2Si = SiMes_2 favorably, and an isomer of the reactant like complex (precursor) may afford an adduct of the different stereochemistry via internal rotations. Generally, the dimer of the alcohol or phenol is the reactant toward the disilenes. Exceptionally, a monomer of p-(dimethylamino)phenol reacts with Mes_2Si = SiMes_2 owing to the steric congestion by four mesityl groups.
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