Gold(I)-Catalyzed Diastereo- and Enantioselective 1,3-Dipolar Cycloaddition and Mannich Reactions of Azlactones

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• 作者：Asa D. Melhado ; Giovanni W. Amarante ; Z. Jane Wang ; Marco Luparia ; F. Dean Toste
• 刊名：Journal of the American Chemical Society
• 出版年：2011
• 出版时间：March 16, 2011
• 年：2011
• 卷：133
• 期：10
• 页码：3517-3527
• 全文大小：1211K
• 年卷期：v.133,no.10(March 16, 2011)
• ISSN：1520-5126

文摘

Azlactones participate in stereoselective reactions with electron-deficient alkenes and N-sulfonyl aldimines to give products of 1,3-dipolar cycloaddition and Mannich addition reactions, respectively. Both of these reactions proceed with good to excellent diastereo- and enantioselectivity using a single class of gold catalysts, namely C₂-symmetric bis(phosphinegold(I) carboxylate) complexes. The development of the azlactone Mannich reaction to provide fully protected anti-伪,尾-diamino acid derivatives is described. 1,3-Dipolar cycloaddition reactions of several acyclic 1,2-disubstituted alkenes and the chemistry of the resultant cycloadducts are examined to probe the stereochemical course of this reaction. Reaction kinetics and tandem mass spectrometry studies of both the cycloaddition and Mannich reactions are reported. These studies support a mechanism in which the gold complexes catalyze addition reactions through nucleophile activation rather than the more typical activation of the electrophilic reaction component.