| Project/Area Number |
10640574
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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 |
物質変換
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| Research Institution | Ochanomizu University |
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Principal Investigator |
YAMADA Shinji Faculty of Science, Ochanomizu University, Associate Professor, 理学部, 助教授 (30183122)
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| Co-Investigator(Kenkyū-buntansha) |
山田 眞二 お茶の水女子大学, 理学部, 助教授 (30183122)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 1999: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1998: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | twisted amide / asymmetric addition / 1,4-dihydropyridine / face-selective addition / neighboring group effect / nicotinic amide / orbital interaction / pyridinium cation |
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| Research Abstract |
Chiral 1,4-dihydropyridines have received considerable attention as NAD models and synthetic intermediates for various natural products. In general, chiral 1,4-dihydropyridines are synthesized by the addition of nucleophiles to pyridinium salts under chelation control. However, we synthesized them based on a new concept. Thus, axial chirality of an amide bond was employed for discrimination of pyridinium faces. Addition of various nucleophiles to the pyridinium salts of nicotinic amides bearing chiral 1,3-thiazolidine-2-thiones gave (R)-1,4-dihydropyridines, of which stereochemistry was determined by X-ray analysis. To clarify the mechanism of this reaction, 1H and 13C NMR measurements and ab initio 3-21G* calculations were performed. These studies suggest that C4-C3-CO-N-C=S moiety makes helical structure with twisted amide linkage, moreover, the unusual structure was stabilized by intramolecular HOMO-LUMO interaction.
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