Kinetic and Structure-Activity Studies of the Triazolium Ion- Catalyzed Intramolecular Stetter Reaction
Kinetic and Structure-Activity Studies of the Triazolium Ion- Catalyzed Intramolecular Stetter Reaction
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DOI：
10.1002/ejoc.202100384
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发表时间：
2021-05-31
影响因子：
2.8
通讯作者：
Smith, Andrew D.
中科院分区：
文献类型：
--
作者：
Collett, Christopher J.;Young, Claire M.;Smith, Andrew D.
三唑鎓离子催化的分子内Stetter反应的机理研究--以NEt 3/NEt 3为例。HCl缓冲的甲醇表明，在很宽的醛浓度范围内，反应在催化剂中为一级反应，在醛中为零级反应。观察到的反应速率是较高的催化剂轴承N-芳基取代基与吸电子基团。一个并发的，NHC独立的底物异构化也观察到，并发现表现出一阶依赖于醛浓度。所报道的数据与去质子化形成Breslow中间体在该过程中是周转限制的一致。
Mechanistic studies of the triazolium ion-catalyzed intramolecular Stetter reaction using initial rates analysis in NEt3/NEt3 . HCl buffered methanol showed the reaction to be first-order in catalyst and zero-order in aldehyde over a broad range of aldehyde concentrations. The observed reaction rate is higher for catalysts bearing N-aryl substituents with electron-withdrawing groups. A concurrent, NHC-independent substrate isomerization was also observed and found to demonstrate a first-order dependence on aldehyde concentration. The reported data are consistent with deprotonation to form the Breslow intermediate being turnover-limiting in this process.