Department of Chemistry , Southern University of Science and Technology , Shenzhen , 518055 , P. R. China.
P. R. China Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province , Shantou University , Guangdong 515063 , P. R. China.
J Org Chem. 2018 May 4;83(9):5009-5018. doi: 10.1021/acs.joc.8b00160. Epub 2018 Apr 12.
DFT calculations are used to address the mechanism of Ni-catalyzed esterification of aryl and alkyl amides. The insight of the tailor-made catalysts in the chemo-selectivity is addressed in this work. The reaction steps for esterification of aryl and alkyl amides catalyzed by both Ni(SIPr) and Ni(terpyridine) include: oxidative addition, metathesis, and reductive elimination processes. Ni(SIPr) can catalyze the esterification of aryl amides rather than Ni(terpyridine) due to high reaction barrier in oxidative addition process, while Ni(terpyridine) can catalyze the esterification of alkyl amides rather than Ni(SIPr) due to high reaction barrier in metathesis process. It is found that the charge distribution on Ni is different in these two complexes. An amino-substituted terpyridine Ni complex is designed to catalyze both aryl and alkyl amides through low transition-state energies because of the electron-donating ability of three amino substitutes. The results reveal that the chemo-selectivity is mainly controlled by the electron-donating ability of ligands.
DFT 计算被用于研究 Ni 催化的芳基和烷基酰胺酯化反应的机理。本工作研究了定制催化剂在化学选择性方面的作用。Ni(SIPr)和 Ni(三联吡啶)催化的芳基和烷基酰胺酯化反应步骤包括：氧化加成、交叉偶联和还原消除过程。由于氧化加成过程中反应势垒较高，Ni(SIPr)可以催化芳基酰胺的酯化反应，而不是 Ni(三联吡啶)；而 Ni(三联吡啶)可以催化烷基酰胺的酯化反应，因为交叉偶联过程中反应势垒较高。结果表明，这两个配合物中 Ni 上的电荷分布不同。通过设计一个氨基取代的三联吡啶 Ni 配合物，由于三个氨基取代基的供电子能力，它可以催化芳基和烷基酰胺的反应。结果表明，化学选择性主要由配体的供电子能力控制。
