Thiol-Ene Click Chemistry: Computational and Kinetic Analysis of the Influence of Alkene Functionality
Thiol-Ene Click Chemistry: Computational and Kinetic Analysis of the Influence of Alkene Functionality
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DOI：
10.1021/ja305441d
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发表时间：
2012-08-22
影响因子：
15
通讯作者：
Coffey, Roderick N.
中科院分区：
文献类型：
--
作者：
Northrop, Brian H.;Coffey, Roderick N.
烯烃官能团对自由基引发的硫醇-烯点击化学的能量学和动力学的影响已在 CBS-QB3 水平上进行了计算研究。沿着甲硫醇与一系列 12 种烯烃之间的硫醇-烯反应的逐步增长机制，已确定了所有驻点的相对能量学（Delta H 度、Delta H-双匕首、Delta G 度、Delta G（双匕首））：丙烯、甲基乙烯基醚、甲基烯丙基醚、降冰片烯、丙烯腈、丙烯酸甲酯、丁二烯、甲基（乙烯基）硅烷二胺、巴豆酸甲酯、富马酸二甲酯、苯乙烯和马来酰亚胺。电子结构计算揭示了控制传播和链转移过程的激活势垒的潜在因素。阶梯式增长机制。结果进一步扩展以预测正向和反向传播以及链转移步骤的速率常数（k(P)、k(-P)、k(CT)、k(-CT)），并用于模拟整体反应动力学。硫醇-烯反应中烯烃结构和反应性之间的关系源自动力学建模的结果，并且可以与从电子结构计算获得的驻点的相对能量直接相关。结果预测了烯烃的反应顺序，并对硫醇-烯点击化学的使用和应用具有广泛的影响。
The influence of alkene functionality on the energetics and kinetics of radical initiated thiol-ene click chemistry has been studied computationally at the CBS-QB3 level. Relative energetics (Delta H degrees, Delta H-double dagger, Delta G degrees, Delta G(double dagger)) have been determined for all stationary points along the step-growth mechanism of thiol-ene reactions between methyl mercaptan and a series of 12 alkenes: propene, methyl vinyl ether, methyl allyl ether, norbornene, acrylonitrile, methyl acrylate, butadiene, methyl(vinyl)silanediamine, methyl crotonate, dimethyl fumarate, styrene, and maleimide. Electronic structure calculations reveal the underlying factors that control activation barriers for propagation and chain-transfer processes of the. step-growth mechanism. Results are further extended to predict rate constants for forward and reverse propagation and chain-transfer steps (k(P), k(-P), k(CT), k(-CT)) and used to model overall reaction kinetics. A relationship between alkene structure and reactivity in thiol-ene reactions is derived from the results of kinetic modeling and can be directly related to the relative energetics of stationary points obtained from electronic structure calculations. The results predict the order of reactivity of alkenes and have broad implications for the use and applications of thiol-ene click chemistry.