Enantioselective Epoxidation of Alkenes Catalyzed by 2-Fluoro-N-Carbethoxytropinone and Related Tropinone Derivatives
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- 作者：Alan Armstrong ; Ghafoor Ahmed ; Belen Dominguez-Fernandez ; Barry R. Hayter ; and J. Steven Wailes
- 刊名：Journal of Organic Chemistry
- 出版年：2002
- 出版时间：November 29, 2002
- 年：2002
- 卷：67
- 期：24
- 页码：8610 - 8617
- 全文大小：141K
- 年卷期：v.67,no.24(November 29, 2002)
- ISSN：1520-6904
文摘
Several 
-substituted N-carbethoxytropinones have been evaluated as catalysts for asymmetricepoxidation of alkenes with Oxone, via a dioxirane intermediate. -Fluoro-N-carbethoxytropinone(2) has been studied in detail and is an efficient catalyst which does not suffer from Baeyer-Villiger decomposition and can be used in relatively low loadings. This ketone was prepared inenantiomerically pure form using chiral base desymmetrization of N-carbethoxytropinone. Asymmetric epoxidation catalyzed by 2 affords epoxides with up to 83% ee. Among other derivativestested, the -acetoxy derivative 7 affords the highest enantioselectivities.
-substituted N-carbethoxytropinones have been evaluated as catalysts for asymmetricepoxidation of alkenes with Oxone, via a dioxirane intermediate. -Fluoro-N-carbethoxytropinone(2) has been studied in detail and is an efficient catalyst which does not suffer from Baeyer-Villiger decomposition and can be used in relatively low loadings. This ketone was prepared inenantiomerically pure form using chiral base desymmetrization of N-carbethoxytropinone. Asymmetric epoxidation catalyzed by 2 affords epoxides with up to 83% ee. Among other derivativestested, the -acetoxy derivative 7 affords the highest enantioselectivities.