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[摘要]:Asymmetric domino Michael acetalization reactions of 2-hydroxynitrostyrene and 2-oxocyclohexanecarbaldehyde with a bifunctional thioureatertiary-amine organocatalyst, e.g., the Takemoto catalyst, followed by oxidation providing the 1',3-spiro-2'-oxocyclohexan-3,4-dihydrocoumarin having one all-carbon quaternary stereocenter with excellent diastereo- and enantioselectivities (up to >99% ee), are described. The structures and absolute configurations of the products were confirmed by X-ray analysis. |
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