2004 Fiscal Year Final Research Report Summary
Development of practical catalytic asymmetric processes based on binuclear metal complexes
| Project/Area Number |
14370715
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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 |
Chemical pharmacy
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
HASHIMOTO Shunichi Hokkaido Univ., Graduate School of Pharmaceutical Silences, Professor, 大学院・薬学研究科, 教授 (80107391)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Seiichi Hokkaido Univ., Graduate School of Pharmaceutical Silences, Associate Professor, 大学院・薬学研究科, 助教授 (90261320)
ANADA Masahiro Hokkaido Univ., Graduate School of Pharmaceutical Silences, Instructor, 大学院・薬学研究科, 助手 (90344473)
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| Project Period (FY) |
2002 – 2004
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| Keywords | Dirhodium(II) Complexes / α-Diazocarbonyl Compounds / Catalysis / Asymmetric Reactions / Carbenes / Nitrenes / C-H Insertion Reaction / C-H Amidation Reaction |
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| Research Abstract |
1.We have found that the enantioselective intramolecular C-H insertion reaction of aryldiazoacetates catalyzed by dirhodium tetrakis[N-phthaloyl-(S)-tert-leucinate], Rh_2(S-PTTL)_4, proceeded at -78 ℃ to provide exclusively cis-2-aryl-3-methoxycarbonyl-2,3-dihydobenzofurans in up to 94% ee.We have also found that Rh_2(S-PTTL)_4-catalyzed intramolecular C-H insertion reaction of α-diazoester gave cis-2-arylcyclopentanecarboxylate with up to 97% ee.
2.Dirhodium(II) tetrakis[N-tetrafluorophthaloyl-(S)-tert-leucinate], Rh_2(S-TFPTTL)_4, in which the phthalimido hydrogen atoms of the parent dirhodium(II) complex are substituted by fluorine atoms, dramatically enhances the reactivity and enantioselectivity (up to 97% ee) in intramolecular aromatic C-H insertion reactions of methyl 4-alkyl-2-diazo-4,4-diphenyl-3-oxopropionates. Catalysis with the use of 0.001 mol % of Rh_2(S-TFPTTL)_4 has achieved the highest turnover number (up to 98,000 with the methyl substituent) ever recorded for chiral dirhodium(II) complex-catalyzed carbene transformations, without compromising the yield or enantioselectivity. We also found that Rh_2(S-TFPTTL)_4 has been found to be well suited for enantioselective nitrene transfer reaction of silyl encl ether with [(2-nitrophenyl)sulfonylimino]phenyliodinane. The observed enantioselectivity of up to 99% ee is the highest reported to date for dirhodium(II) complex-catalyzed nitrene transformations.
3.We have found that enantioselective 1,3-dipolar cycloaddition of the keto-carbonyl ylide with aromatic aldehyde has been effected with the aid of Rh_2(S-BPTV)_4, affording cycloadducts with perfect exo-selectivity and enantioselectivities in excess of 92%. We also found that cycloaddition of keto-carbonyl ylide derived from α-diazo-β-ketoester with ethynylarenes under the influence of Rh_2(S-TCPTTL)_4 afforded cycloadduct in 97% ee.
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