Kinetic and stereochemical evidence for the involvement of only one proline molecule in the transition states of proline-catalyzed intra- and intermolecular aldol reactions
Kinetic and stereochemical evidence for the involvement of only one proline molecule in the transition states of proline-catalyzed intra- and intermolecular aldol reactions
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DOI：
10.1021/ja028634o
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发表时间：
2003-01-08
影响因子：
15
通讯作者：
List, B
中科院分区：
文献类型：
--
作者：
Hoang, L;Bahmanyar, S;List, B
与广泛接受的Hajos-Parrish-Eder-Sauer-Wiechert反应机制相反，我们已经获得了只有一个脯氨酸分子参与分子间和分子内羟醛缩合反应过渡态的证据。我们的结论是基于动力学测量以及不对称催化不存在非线性和稀释效应，并得到B3 LYP/6- 31 G * 计算的支持。补充最近的理论研究，我们的研究结果提供了一个统一的烯胺催化机理的脯氨酸催化的分子间和分子内羟醛缩合反应的基础。
Contrary to the widely accepted mechanism of the Hajos−Parrish−Eder−Sauer−Wiechert reaction, we have obtained evidence for the involvement of only one proline molecule in the transition states of both inter- and intramolecular aldol reactions. Our conclusions are based on kinetic measurements and the absence of nonlinear and dilution effects on the asymmetric catalysis, and are supported by B3LYP/6-31G* calculations. Complementary to recent theoretical studies, our results provide the foundation of a unified enamine catalysis mechanism of proline-catalyzed inter- and intramolecular aldol reactions.