稀土氯化物催化合成降冰片烯衍生物

SYNTHESIS OF NORBORNENE DERIVATIVES CATALYZED BY LANTHANIDE CHLORIDES

将稀土氯化物作为Diels-Alder环加成反应的催化剂,在缓和条件下制得了几种降冰片烯衍生物。稀土氯化物不仅提高了反应速度,而且还改变了产物的构型比(endo/exo)。由试验的几种稀土氯化物的结果,可以看出催化活性有随稀土元素原子序数递增而增加的趋势。降低反应温度有利于内型产物的生成。比较了催化与非催化反应的活化能和级数。

Several nolborncnc derivatives were Synthesized via Diels-Alder cycloaddi-tion under mild conditions by using lanthanide chlorides as catalysts. Lanthanide chlorides increase not only the reaction rate, but also change the endo/exo ratio of the products. From the experimental results of five lanthanide chlorides, HoCl3, TbCl3, GdCl3, EuCl3, and NdCl3 tested, it can be seen that the catalytic activity is enhanced with the increase of the atomic number of rare earth elements. The decrease of reaction temperature is in favour of the formation of endo configuration. The activation energy and leaclion order were calculated and compared fot catalytic and non-catalytic cycloaddition.