Development of the Juliá asymmetric epoxidation reaction. Part 2. Application of the oxidation to alkyl enones, enediones and unsaturated keto esters
摘要:
Polyleucine-based systems have been used to catalyse the asymmetric oxidation of a variety of alkyl enones 1-4,9-14, an enynone 16 and a dienone 17 to afford the corresponding epoxides 5-8, 18-26 in good to excellent yield and optical purity. A range of enediones 30-32, 34 and one unsaturated keto ester 33 have also been epoxidised stereoselectively to afford optically active epoxides 35-39. The epoxidations were carried out with basic peroxide as the oxidant; the polyleucine catalyst was prepared from leucine N-carboxyanhydride using 1,3-diaminopropane, water (employing a humidity cabinet) or a polystyrene immobilised amine as the initiator. Preliminary mass spectral data on material derived from L-leucine and 1,3-diaminopropane (DAP-PLL) suggest that the catalyst consists of material that contains 22 +/- 10 leucine residues.
Development of the Juliá asymmetric epoxidation reaction. Part 2. Application of the oxidation to alkyl enones, enediones and unsaturated keto esters
摘要:
Polyleucine-based systems have been used to catalyse the asymmetric oxidation of a variety of alkyl enones 1-4,9-14, an enynone 16 and a dienone 17 to afford the corresponding epoxides 5-8, 18-26 in good to excellent yield and optical purity. A range of enediones 30-32, 34 and one unsaturated keto ester 33 have also been epoxidised stereoselectively to afford optically active epoxides 35-39. The epoxidations were carried out with basic peroxide as the oxidant; the polyleucine catalyst was prepared from leucine N-carboxyanhydride using 1,3-diaminopropane, water (employing a humidity cabinet) or a polystyrene immobilised amine as the initiator. Preliminary mass spectral data on material derived from L-leucine and 1,3-diaminopropane (DAP-PLL) suggest that the catalyst consists of material that contains 22 +/- 10 leucine residues.
Unexpected asymmetric epoxidation reactions catalysed by polyleucine-based systems
作者:Wolfgang Kroutil、Patrick Mayon、M. Elena Lasterra-Sánchez、Samuel J. Maddrell、Stanley M. Roberts、Steven R. Thornton、Christine J. Todd、Melek Tüter
DOI:10.1039/cc9960000845
日期:——
Polyleucine-based systems have been shown to catalyse the asymmetric epoxidation of a variety of enones, an enynone, selected enediones and an unsaturated ketoester.
Development of the Juliá asymmetric epoxidation reaction. Part 2. Application of the oxidation to alkyl enones, enediones and unsaturated keto esters
作者:Wolfgang Kroutil、M. Elena Lasterra-Sánchez、Samuel J. Maddrell、Patrick Mayon、Phillip Morgan、Stanley M. Roberts、Steven R. Thornton、Christine J. Todd、Melek Tüter
DOI:10.1039/p19960002837
日期:——
Polyleucine-based systems have been used to catalyse the asymmetric oxidation of a variety of alkyl enones 1-4,9-14, an enynone 16 and a dienone 17 to afford the corresponding epoxides 5-8, 18-26 in good to excellent yield and optical purity. A range of enediones 30-32, 34 and one unsaturated keto ester 33 have also been epoxidised stereoselectively to afford optically active epoxides 35-39. The epoxidations were carried out with basic peroxide as the oxidant; the polyleucine catalyst was prepared from leucine N-carboxyanhydride using 1,3-diaminopropane, water (employing a humidity cabinet) or a polystyrene immobilised amine as the initiator. Preliminary mass spectral data on material derived from L-leucine and 1,3-diaminopropane (DAP-PLL) suggest that the catalyst consists of material that contains 22 +/- 10 leucine residues.