Metal-complex-catalyzed isomerization of anils
Metal-complex-catalyzed isomerization of anils
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金属络合物催化苯胺异构化
DOI：
10.1021/ic50205a031
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发表时间：
1980
影响因子：
4.6
通讯作者：
J. Tong
中科院分区：
文献类型：
--
作者：
D. R. Eaton;J. Tong
硫脲的锌(II)络合物催化了A-异亚丙基苯胺的异亚丙基甲基之间的交换。用自旋饱和转移(双共振)质子磁共振研究了催化交换过程的速率。用相同的催化剂将观察到的反应速率与苯胺解和过渡反应的速率进行了比较。与非催化异构化的机理不同，碳-氮键的旋转而不是氮的反转决定了催化异构化的速度。似乎亲核试剂的参与也是完成异构化所必需的。催化异构化反应的活化能为13±2千卡，而非催化异构化反应的活化能为22±2千卡。
Exchange between the nonequivalent isopropylidene methyl groups of A-isopropylideneanilines is catalyzed by zinc (II) complexes of thiourea. The rates of the catalyzed exchange processes have been studied by using spin-saturation-transfer (double resonance) proton magnetic resonance. The observedrates are compared with those for anil hydrolysis and transimination by using the same catalysts. In contrast to the mechanism of the uncatalyzed isomerization, rotation about the carbon-nitrogen bond rather than inversion about the nitrogen determines the rate of the catalyzed isomerization. It seems likely that the participation of a nucleophile is also necessary to accomplish isomerization. The activation energy for catalyzed isomerization is 13±2 kcal as opposed to 22±2 kcal for the uncatalyzed reaction.