Lewis酸催化合成柑菁腈的研究

Studies on the Synthesis of Myrac Nitrile Catalyzed by Lewis Acids

本文比较了一系列Ｌｅｗｉｓ酸在月桂烯与丙烯腈的Ｄｉｅｌｓ－Ａｌｄｅｒ反应中的催化作用，催化剂的酸强度强烈影响月桂烯的转化率、柑菁腈的选择性及对位柑菁腈的区域选择性。这些选择性随反应温度的升高而下降，几乎不随反应时间而变化。利用ＵＶ，ＩＲ及１ＨＮＭＲ等分析研究了ＺｎＣｌ２和ＡｌＣｌ３催化该反应的作用机理，证明反应是由丙烯腈的腈基与Ｌｅｗｉｓ酸的金属离子发生配合作用，使得Ｃ＝Ｃ双键极化，从而改变反应途径，提高反应速度和选择性。

The catalytic activities of a series of Lewis acids were compared in the DielsAlder reaction of myrcene with acrylonitrile. It was found that the acid strength affected the conversion of myrcene. the selectivity of myrac nitrile, and the regioselectivity of para myrac nitrile. All of these selcetivities decreased with increasing reaction temperature and almost unchanged with prolonging reaction time. The catalytic reaction mechanism of the Lewis acids with the acrylonitrile was investigated by UV.IR and HNMR methods. It was proved that the coordination of acrylonitrile with acid centres made the C=C bond polarized and increased their activities.