Asymmetric Catalysis of Diels鈥揂lder Reactions with in Situ Generated Heterocyclic ortho-Quinodimethanes
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- 作者：Yankai Liu ; Manuel Nappi ; Elena Arceo ; Silvia Vera ; Paolo Melchiorre
- 刊名：Journal of the American Chemical Society
- 出版年：2011
- 出版时间：September 28, 2011
- 年：2011
- 卷：133
- 期：38
- 页码：15212-15218
- 全文大小：1013K
- 年卷期：v.133,no.38(September 28, 2011)
- ISSN：1520-5126
文摘
The Diels鈥揂lder reaction is probably the most powerful technology in the synthetic repertoire for single-step constructions of complex chiral molecules. The synthetic power of this fundamental pericyclic transformation has greatly increased with the emergence of asymmetric catalytic variants, and research aimed at further expanding its potential is still exciting and fascinating the chemical community. Here, we document the first asymmetric catalytic Diels鈥揂lder reaction of in situ generated heterocyclic ortho-quinodimethanes (oQDMs), reactive diene species that have never before succumbed to a catalytic approach. Asymmetric aminocatalysis, that uses chiral amines as catalysts, is the enabling strategy to induce the transient generation of indole-, pyrrole- or furan-based oQDMs from simple starting materials, while directing the pericyclic reactions with nitroolefins and methyleneindolinones toward a highly stereoselective pathway. The approach provides straightforward access to polycyclic heteroaromatic compounds, which would be difficult to synthesize by other catalytic methods, and should open new synthetic pathways to complex chiral molecules using nontraditional disconnections.