Bifunctional Catalysis of Ester Aminolysis – A Computational and Experimental Study
Bifunctional Catalysis of Ester Aminolysis – A Computational and Experimental Study
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DOI：
10.1002/jlac.199619961003
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发表时间：
1996-10
期刊：
影响因子：
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通讯作者：
Li-hsing Wang;H. Zipse
中科院分区：
文献类型：
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作者：
Li-hsing Wang;H. Zipse
在 Becke3LYP/6–31G**/HF/6–31G** 理论水平上研究了 2(1H)-吡啶酮催化甲胺与乙酸甲酯反应的各种途径。最有利的途径包括一步反应，其中所有成键和断裂过程同时发生。这些模型研究还表明吡啶酮具有酸的功能，从而引发了对几种取代吡啶酮的研究。通过 Becke3LYP/6–31G**/HF/3–21G 水平的从头计算模型，4-氰基-、3-氰基-6-甲基-和 3-氰基-2(1H)-吡啶酮确实被证明可以在酯氨解反应中提供更好的催化作用。为了验证理论结果，测定了各种取代2-吡啶酮在氯苯溶液中正丁胺与乙酸对硝基苯酯反应中的催化活性。观察到的催化速率常数确实与理论预测一致。然而，其他催化剂特性，例如溶解度和聚集状态，在此反应中也至关重要。
Various pathways for the reaction of methylamine with methyl acetate catalyzed by 2(1H)-pyridone have been investigated at the Becke3LYP/6–31G**/HF/6–31G** level of theory. The most favorable pathway consists of a one-step reaction, in which all bond-forming and -breaking processes occur in concert. These modeling studies also show the pyridone to function as an acid, which led to the investigation of several substituted pyridones. 4-Cyano-, 3-cyano-6-methyl-, and 3-cyano-2(1H)-pyridone have indeed been shown to provide better catalysis in the ester aminolysis reaction by ab initio modeling at the Becke3LYP/6–31G**/HF/3–21G level. In order to verify the theoretical results, the catalytic activities of various substituted 2-pyridones in the reaction of n-butylamine with p-nitrophenyl acetate in chlorobenzene solution have been determined. The observed catalytic rate constants are indeed in agreement with the theoretical predictions. Other catalyst characteristics such as solubility and state of aggregation are, however, also of paramount importance in this reaction.