Enantioselective Staudinger Synthesis of -Lactams Catalyzed by a Planar-Chiral Nucleophile1
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- 作者：Brian L. Hodous and Gregory C. Fu
- 刊名：Journal of the American Chemical Society
- 出版年：2002
- 出版时间：February 27, 2002
- 年：2002
- 卷：124
- 期：8
- 页码：1578 - 1579
- 全文大小：43K
- 年卷期：v.124,no.8(February 27, 2002)
- ISSN：1520-5126
文摘
The development of efficient methods for the stereoselective generation of 
le">-lactams is an important goal, due to their biological activity and their utility as synthetic intermediates. The Staudinger reaction, an overall [2 + 2] cycloaddition of a ketene with an imine, provides a nicely convergent route to this family of compounds. Nearly all studies to date of asymmetric variants of the Staudinger reaction have focused on the use of chiral auxiliaries to control the stereochemistry of the le">-lactam. In this report, we establish that a planar-chiral derivative of 4-(pyrrolidino)pyridine serves as a very effective enantioselective catalyst for the Staudinger le">-lactam synthesis, coupling a range of symmetrical and unsymmetrical ketenes with an array of imines with very good stereoselection and yield.
le">-lactams is an important goal, due to their biological activity and their utility as synthetic intermediates. The Staudinger reaction, an overall [2 + 2] cycloaddition of a ketene with an imine, provides a nicely convergent route to this family of compounds. Nearly all studies to date of asymmetric variants of the Staudinger reaction have focused on the use of chiral auxiliaries to control the stereochemistry of the le">-lactam. In this report, we establish that a planar-chiral derivative of 4-(pyrrolidino)pyridine serves as a very effective enantioselective catalyst for the Staudinger le">-lactam synthesis, coupling a range of symmetrical and unsymmetrical ketenes with an array of imines with very good stereoselection and yield.