Magnesium Coordination-Directed N-Selective Stereospecific Alkylation of 2-Pyridones, Carbamates, and Amides Using α-Halocarboxylic Acids
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- 作者：Yuan-Qing Fang ; Matthew M. Bio ; Karl B. Hansen ; Matthew S. Potter ; Andrew Clausen
- 刊名：Journal of the American Chemical Society
- 出版年：2010
- 出版时间：November 10, 2010
- 年：2010
- 卷：132
- 期：44
- 页码：15525-15527
- 全文大小：219K
- 年卷期：v.132,no.44(November 10, 2010)
- ISSN：1520-5126
文摘
A general inversion-stereospecific, N-selective alkylation of substituted 2-pyridones (and analogues), amides, and carbamates using chiral α-chloro- or bromocarboxylic acids in the presence of KOt-Bu (or KHMDS) and Mg(Ot-Bu)2 is reported. The resulting α-chiral carboxylic acid products were isolated by crystallization in good chemical yields and in high ee (>90% ee). Mechanistic evidence suggests that the reaction proceeds through 2-pyridone O-coordinated Mg carboxylate intermediates, which afford the product through an intramolecular SN2 alkylation.