2005 Fiscal Year Final Research Report Summary
Innovation of Asymmetric Cycloaddition Reactions Based on Highly Efficient Stereocontrol in Multinucleating Chiral Reaction Field
| Project/Area Number |
16550031
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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 |
Organic chemistry
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| Research Institution | Kanazawa University |
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Principal Investigator |
UKAJI Yutaka Kanazawa University, Graduate School of Natural Science and Technology, Professor, 自然科学研究科, 教授 (80193853)
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| Project Period (FY) |
2004 – 2005
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| Keywords | multinucleating / tartaric acid ester / nitrone / asymmetric 1,3-dipolar cycloaddition / o-quinodimethane / asymmetric Diels-Alder reaction / zinc acetylide / asymmetric amplification |
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| Research Abstract |
In order to develop a practical method for the construction of chiral molecules, we have designed a novel chiral system possessing multi-metal centers utilizing tartaric acid ester as a chiral auxiliary.
A catalytic asymmetric 1,3-dipolar cycloaddition of nitrones possessing the N,N-diisopropylamide moiety to allylic alcohols was achieved to afford di- or trisubstituted isoxazolidines with excellent enantioselectivity of up to over 99% ee. The present asymmetric 1,3-dipolar cycloaddition was applied to the synthesis for the (2S,4R)-4-hydroxyornithine derivative.
The regio- and enantioselective hetero Diels-Alder reaction of nitroso compound with dienol has been realized utilizing a catalytic amount of tartaric acid ester as a chiral auxiliary and the corresponding cycloadduct was obtained in complete regioselectivity with excellent enantioselectivity up to 84% ee.
The asymmetric Diels-Alder reaction of o-quinodimethanes, generated from benzocyclobutenols in situ, with fumaric acid esters was achieved by utilizing diisopropyl (R,R)-tartrate as a chiral auxiliary to afford the corresponding optically active 1,2-cis-substituted 1-hydroxy tetrahydronaphthalene derivatives with enantioselectivity up to 83% ee.
The asymmetric addition of alkynylzinc reagents, prepared in situ from dialkylzinc and 1-alkynes, to nitrones was achieved by utilizing di(t-butyl) (R,R)-tartrate as a chiral auxiliary to afford the corresponding optically active (R)-α-substituted propargylic N-hydroxylamines. By the addition of product-like N-hydroxylamine, unprecedented enhancement of enantioselectivity was observed to afford the N-hydroxylamines up to 95% ee.
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