Enantioselective Epoxidation of Alkenes Catalyzed by 2-Fluoro-<i>N</i>-Carbethoxytropinone and Related Tropinone Derivatives
作者:Alan Armstrong、Ghafoor Ahmed、Belen Dominguez-Fernandez、Barry R. Hayter、J. Steven Wailes
DOI:10.1021/jo026322y
日期:2002.11.1
N-carbethoxytropinones have been evaluated as catalysts for asymmetric epoxidation of alkenes with Oxone, via a dioxirane intermediate. alpha-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 in enantiomerically pure form using chiral base desymmetrization
已经评估了几种α-取代的N-碳乙氧基肌醇酮,作为经由二环氧乙烷中间体的烯烃与酮的不对称环氧化的催化剂。已对α-氟-N-甲氧羰基肌酮(2)进行了详细研究,它是一种高效的催化剂,不会受到拜尔-维利格分解的影响,并且可以以较低的负载量使用。使用N-碳乙氧基肌醇酮的手性碱去对称化,以对映体纯的形式制备该酮。2催化的不对称环氧化反应可提供ee高达83%的环氧化物。在测试的其他衍生物中,α-乙酰氧基衍生物7具有最高的对映选择性。