1999 Fiscal Year Final Research Report Summary
Development of Stereoselective Reactions by Using Newly Prepared Optically Active Pyrazole Derivatives
| Project/Area Number |
09440246
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | Kyushu University |
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Principal Investigator |
ITO Yoshio Kyushu Univ., Fac. Sci., Associate Professor, 大学院・理学研究科, 助教授 (00221086)
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| Co-Investigator(Kenkyū-buntansha) |
KATSUKI Tsutomu Kyushu Univ., Fac. Sci., Professor, 大学院・理学研究科, 教授 (40037271)
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| Project Period (FY) |
1997 – 1999
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| Keywords | pyrazole / Diels-Alder / epoxidation / (salen)manganese complex / diaziridine / cis-aziridine / asymmetric aziridination / non-stereospecific |
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| Research Abstract |
This research was started from 1997 by focusing on the feature of heteroatoms for setereoselective reactions. At the beginnings, we examined asymmetric Diels-Alder reaction by using optically active diol derived from menthone. Only by switching the solvent from THF to dicholoromethane, reversal of enantioface selectively was observed. On the other hand, optically active pyrazole derivatives derived from menthone was found to regulate the conformation of achiral (salen)manganese complex as axial ligand. This conformational regulation for the first time realized asymmetric epoxidation with achiral catalyst, though the asymmetric induction was low. The hypothesis that the stepped ligand conformation of (salen)manganese complex plays an important role in the enantioface selection by the salen complex is strongly supported by the present experimental results. Basing in this consideration, new type of (salen)manganese complex bearing carboxylate group on its ethylene diamine moiety was prepared and used as a catalyst for asymmetric epoxidation of chromene derivatives. In addition to the quantitative yield and excellent asymmetric of 98% ee, high turn over number of about 10000 was achieved.
On the other hand, we developed cis-selective and non-stereospecific aziridination of α, β-unsaturated amide by using a diaziridine. Employment of optically active daiziridine made asymmetric aziridination possible in excellent % ee though the chemical yield was only modest.
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