1.Organocatalytic enantioselective [3+3] and [4+2] annulation of ?β-unsaturated aldehyde2.Organocatalytic double Michael and Michael-Henry reaction of aldehydes and β-nitrostyrene
博士 === 國立中正大學 === 化學所 === 97 === In chapter one, we describe the highly enantioselective organocatalyzed carbo [3 + 3] cycloaddition and [4 + 2] annulation of ?β-unsaturated aldehydes. The structure of the [3 + 3] adduct was confirmed by X-ray analysis of adduct. The [4 + 2] Robinson annulation cata...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2008
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| Online Access: | http://ndltd.ncl.edu.tw/handle/07414088361779357400 |
| Summary: | 博士 === 國立中正大學 === 化學所 === 97 === In chapter one, we describe the highly enantioselective organocatalyzed carbo [3 + 3] cycloaddition and [4 + 2] annulation of ?β-unsaturated aldehydes. The structure of the [3 + 3] adduct was confirmed by X-ray analysis of adduct. The [4 + 2] Robinson annulation catalyzed by L-proline and trialkylamines or diarylpyrrolinol silyl ethers afforded the adducts with high enantioselectivity (>99.5% e.e.). The structures of the [4 + 2] adducts obtained from the reaction of 4-oxobut-2-enyl acetate and (E)-3- (2-nitrophenyl)acrylaldehyde were not only confirmed by X-ray analysis, but also confirmed by spectra analysis of the product obtained from the reaction of 4-oxobut-2-enyl acetates .
In chapter two, we discuss the organocatalytic Michael-Henry and double Michael reaction of aldehydes and β-nitrostyrene. The Michael-Henry reaction afforded substituted chiral nitrocyclohexanecarbaldehydes with excellent diastereoselectivity and control of four stereogenic centers. The structure of cyclohexanecarbaldehyde was confirmed by the X-ray structure analysis. The double Michael reaction also afforded the highly functionalized cyclohexanecarboester with four stereogenic centers with high diastereoselectivity and high enantioselectivity (>99% e.e.). Application of the reactions to the corresponding dialdehyde provided bicyclo[2.2.2]octanes via Michael-Michael-aldol condensation reaction.
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