Adolfsson H, Copéret C, Chiang J P, Yudin A K
Department of Chemistry and the Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 90237, USA.
J Org Chem. 2000 Dec 15;65(25):8651-8. doi: 10.1021/jo005623+.
The epoxidation of alkenes with 30% aqueous hydrogen peroxide is catalyzed efficiently by methyltrioxorhenium (MTO) in the presence of pyridine additives. The addition of 1-10 mol % of 3-cyanopyridine increases the system's efficiency for terminal and trans-disubstituted alkenes resulting in high isolated yields of the corresponding epoxides. The system allows for epoxidation of alkenes with various functional groups. Alkenes leading to acid-sensitive products are efficiently epoxidized using a mixture of pyridine and 3-cyanopyridine as additives. This method is operationally very simple and uses an environmentally benign oxidant. The effects of different pyridine additives on the alkene conversion and the catalyst lifetime are discussed.
在吡啶添加剂存在下，甲基三氧化铼（MTO）能有效催化30%过氧化氢水溶液对烯烃的环氧化反应。添加1 - 10摩尔%的3 - 氰基吡啶可提高该体系对末端烯烃和反式二取代烯烃的反应效率，从而使相应环氧化物的分离产率较高。该体系可实现带有各种官能团烯烃的环氧化反应。对于生成酸敏感产物的烯烃，使用吡啶和3 - 氰基吡啶的混合物作为添加剂可有效进行环氧化反应。此方法操作非常简单，且使用的是环境友好型氧化剂。文中还讨论了不同吡啶添加剂对烯烃转化率和催化剂寿命的影响。
