Weaker Lewis acid, better catalytic activity: dual mechanisms in perfluoroarylborane-catalyzed allylstannation reactions.
Weaker Lewis acid, better catalytic activity: dual mechanisms in perfluoroarylborane-catalyzed allylstannation reactions.
复制标题
路易斯酸越弱，催化活性越好：全氟芳基硼烷催化烯丙基锡化反应的双重机制。
DOI：
10.1002/chin.200349038
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发表时间：
2003
期刊：
影响因子：
5.2
通讯作者：
W. Piers
中科院分区：
文献类型：
--
作者：
D. J. Morrison;W. Piers
[反应：PhB（C（6）F（5））（2）作为刘易斯酸催化剂用于芳族醛的烯丙基锡化反应，比更强的刘易斯酸B（C（6）F（5））（3）显示出高得多的活性。这种反常的增强较弱的LA的催化活性示出部分是由于在反应的产物形成步骤中的离子对2b相对于2a的热力学稳定性降低。对于弱刘易斯酸性硼烷，硼烷作为真正的LA催化剂的机理路径更为重要。
[reaction: see text] PhB(C(6)F(5))(2) exhibits much higher activity as a Lewis acid catalyst for the allylstannation of aromatic aldehydes than the stronger Lewis acid B(C(6)F(5))(3). This anomalous enhancement of catalytic activity for the weaker LA is shown to be partly due to decreased thermodynamic stability of ion pair 2b relative to 2a in the product-forming step of the reaction. A mechanistic path where the borane serves as the true LA catalyst is more important for the weakly Lewis acidic borane.