Asymmetric Kinugasa Reaction of Cyclic Nitrones and Nonracemic Acetylenes

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• 作者：Sebastian Stecko ; Adam Mames ; Bartlomiej Furman ; Marek Chmielewski
• 刊名：Journal of Organic Chemistry
• 出版年：2009
• 出版时间：April 17, 2009
• 年：2009
• 卷：74
• 期：8
• 页码：3094-3100
• 全文大小：271K
• 年卷期：v.74,no.8(April 17, 2009)
• ISSN：1520-6904

文摘

Kinugasa reactions between chiral acetylenes and five-membered nitrones, achiral and bearing a stereogenic center in both enantiomeric forms, proceed in moderate to good yield with high diastereoselectivity affording mostly one dominant product. The first step of the reaction is controlled by the configuration of the nitrone, whereas the protonation of intermediate enolate in the second step depends mainly on the configuration of the bridgehead carbon atom formed in the first step. In the case of the mismatched pair, the configuration at the C-6 center of the carbapenam skeleton may also be affected by the configuration of the stereogenic center in the acetylene portion.