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有机化学
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有机化学 ›› 1992, Vol. 12 ›› Issue (1): 29-34. 上一篇    下一篇

研究论文

催化量的氧化钙-硅胶对Sharpless烯丙醇不对称环氧化的影响

王志民;周维善   

  1. 中国科学院上海有机化学研究所
  • 发布日期:1992-02-25

The effect of catalytic amount of calcium hydride and silica gel on Sharpless asymmetric epoxidation

WANG ZHIMIN;ZHOU WEISHAN   

  • Published:1992-02-25

当在Sharpless试剂中加入催化量的金属氢化物和硅胶后, 烯丙醇的不对称环氧化反应时间大为缩短, 而化学和光学产率不受影响。着重讨论了氢化钙和硅胶对Sharpless烯丙醇不对称环氧化的作用。

关键词: 环氧化反应, 不对称, 氢化钙, 酒石酸 P, 钛络合物, 丙氧基, 硅胶, 金属氢化物, 烯丙醇

The reaction time of asym. epoxidn. of allylic al. was drastically reduced whereas the enantioselectivity increased when a catalytic amount of CaH2 and SiO2 was present in the Sharpless reagent. Transition state studies indicated a SN2 mechanism, in which the interaction between Ca2+ and O in the peroxide species accelerated the O-O bond cleavage and increased the reaction rate. The adsorbed Ca2+ on SiO2 prevented the decrease in enantioselectivity.

Key words: TARTARIC ACID P, EPOXIDATION REACTION, ASYMMETRY, TITANIUM COMPLEX, CALCIUM HYDRIDE, PROPOXY GROUP, SILICA GEL, METAL HYDRIDE, ALLYL ALCOHOL

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