Transition-state charge stabilization through multiple non-covalent interactions in the guanidinium-catalyzed enantioselective Claisen rearrangement.
Transition-state charge stabilization through multiple non-covalent interactions in the guanidinium-catalyzed enantioselective Claisen rearrangement.
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DOI：
10.1021/ja110842s
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发表时间：
2011-04-06
影响因子：
15
通讯作者：
Jacobsen EN
中科院分区：
文献类型：
--
作者：
Uyeda C;Jacobsen EN
通过实验和计算方法研究了手性芳基吡咯取代胍离子促进O-烯丙基α-酮酯Claisen重排并诱导对映选择性的机理.除了通过氢键捐赠稳定重排过渡态的草烯丙基片段上的负电荷外，还获得了催化剂芳族取代基的π-系统与阳离子烯丙基片段之间的次级吸引相互作用的证据。在一系列取代的芳基吡咯衍生物中，观察到对映选择性根据该提议可预测地变化。这种机理分析导致了一种新的对-二甲基氨基苯基取代的催化剂的开发，该催化剂相对于母体苯基催化剂对于一组代表性的底物提供了对映选择性的改进。
The mechanism by which chiral arylpyrrole-substituted guanidinium ions promote the Claisen rearrangement of O-allyl α-ketoesters and induce enantioselectivity was investigated by experimental and computational methods. In addition to stabilization of the developing negative charge on the oxallyl fragment of the rearrangement transition state by hydrogen-bond donation, evidence was obtained for a secondary attractive interaction between the π-system of a catalyst aromatic substituent and the cationic allyl fragment. Across a series of substituted arylpyrrole derivatives, enantioselectivity was observed to vary predictably according to this proposal. This mechanistic analysis led to the development of a new p-dimethylaminophenyl-substituted catalyst, which afforded improvements in enantioselectivity relative to the parent phenyl catalyst for a representative set of substrates.
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DOI：
10.1073/pnas.90.18.8600
发表时间：
1993-09-15
影响因子：
11.1
作者：
CHOOK, YM;KE, HM;LIPSCOMB, WN
通讯作者：
LIPSCOMB, WN
影响因子：
1.8
作者：
Abraham, L;Körner, M;Hiersemann, M
通讯作者：
Hiersemann, M
影响因子：
1.8
作者：
CURRAN, DP;KUO, LH
通讯作者：
KUO, LH
影响因子：
15
作者：
Anderson, CE;Overman, LE
通讯作者：
Overman, LE
影响因子：
15
作者：
Donoghue, Patrick J.;Helquist, Paul;Wiest, Olaf
通讯作者：
Wiest, Olaf