1999 Fiscal Year Final Research Report Summary
Design of a Chiral Dinucleating System Utilizing Tartaric Acid Ester as a Chiral Auxiliary and Its Application to the Synthesis of Optically Active Compounds
| Project/Area Number |
10640515
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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 Associate Professor, 自然科学研究科, 助教授 (80193853)
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| Project Period (FY) |
1998 – 1999
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| Keywords | dinucleating / tartaric acid ester / chiral / 1,3-dipolar cycloaddition reaction / nitrile oxide / 2-isoxazoline / Reformatsky-type reagent / β-amino acid |
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| Research Abstract |
It is strongly required to develop a practical and efficient method for the construction of chiral molecules to explore new biologically active medicines and agricultural chemicals. In this research, a new and novel chiral system possessing two metal centers utilizing tartaric acid esters was designed ; that is, if two reactants are bound to two different metal centers of the dialkoxide derived from tartaric acid ester, which might actually form the rigid 5/5-fused bicyclic dinucleating structure, they might be ideally oriented and/or activated by the metals and the following reaction might proceed in an enantioselective manner to afford the corresponding optically active products.
The asymmetric 1,3-dipolar cycloaddition of nitrile oxides to ethyl (E)-4-hydroxy-2-butenoate was achieved by the use of diisopropyl (R,R)-tartrate as a chiral auxiliary to afford the corresponding 4,5-trans-2-isoxazolines, which were transformed to the corresponding 4,5-cis-2-isoxazolines by the treatment with a base through isomerization and lactonization.
The asymmetric addition of the Reformatsky-type reagent, prepared in situ from diethylzinc and iodoacetic acid ester, to a carbon-nitrogen double bond in 3,4-dihydroisoquinoline N-oxides was achieved with enantioselectivity up to 86% ee. Furthermore, the asymmetric addition of the Reformatsky-type reagent to imines prepared from aldehydes and 2-aminophenol was also achieved to give β-amino acid derivatives. In order to realize reproducible higher stereoselection, the addition of a small amount of water was crucial.
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Research Products
(14 results)
