CLAISEN REARRANGEMENT OF ALLYL PHENYL ETHER - 1-C-14 AND BETA-C-14 KINETIC ISOTOPE EFFECTS - A CLEARER VIEW OF THE TRANSITION STRUCTURE
CLAISEN REARRANGEMENT OF ALLYL PHENYL ETHER - 1-C-14 AND BETA-C-14 KINETIC ISOTOPE EFFECTS - A CLEARER VIEW OF THE TRANSITION STRUCTURE
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DOI：
10.1021/ja00035a042
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发表时间：
1992-04-22
影响因子：
15
通讯作者：
SHINE, HJ
中科院分区：
文献类型：
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作者：
KUPCZYKSUBOTKOWSKA, L;SUBOTKOWSKI, W;SHINE, HJ
测定了烯丙基[1-C-14]苯基醚和[β-C-14]烯丙基苯基醚重排反应的动力学同位素效应KC-12/KC-14，分别为1.0119+/-0.0009和1.0148+/-0.0005。这些结果与早先报道的O-18、2-C-14、α-C-14和伽马-C-14的结果一起，代表了对周环体系的第一个完整的动力学同位素效应(KIE)描述。模拟计算已经应用于重原子Kie和以前报道的重氢Kie，以更明确地定义重排的跃迁结构。计算证实了我们早先的描述，即C(α)-O键断裂了50-60%，而C(伽马)-C(邻位)键形成了10-20%，现在对重排的动力学提供了更多的见解。苯氧基和烯丙基片段之间的偶联比先前假设的更强，而片段内的偶联更弱。
The kinetic isotope effects, kC-12/kC-14, for the rearrangements of allyl [1-C-14]phenyl ether and [beta-C-14]allyl phenyl ether have been measured: 1.0119 +/- 0.0009 and 1.0148 +/- 0.0005, respectively. These results, along with those reported earlier for O-18, 2-C-14, alpha-C-14, and gamma-C-14, represent the first complete kinetic isotope effect (KIE) description of a pericyclic system. Modeling calculations have been applied to the heavy-atom KIE and the previously reported deuterium KIE to define the transition structure of the rearrangement more explicitly. The calculations confirm our earlier description that the C(alpha)-O bond is 50-60% broken while the C(gamma)-C(ortho) bond is 10-20% formed and now provide significantly more insight to the dynamics of the rearrangement. Coupling between the phenoxy and allyl fragments is stronger, and within the fragments is weaker, than previously supposed.