A DFT study on the reaction mechanisms of phosphonation of heteroaryl N-oxides with H-phosphonates

作者：Zhang, Wei; Zhao, Xiaoyang; Qiao, Yan; Guo, Xiaokang; Wang, Yanyan; Wei, Donghui^*; Tang, Mingsheng; Niu, Junlong

来源：Computational and Theoretical Chemistry, 2015, 1071: 33-38.

DOI：10.1016/j.comptc.2015.08.012

• Density functional theory
• Heteroaryl phosphonates
• Reaction mechanism
• Phosphonation

In this paper, a density functional theory (DFT) study has been carried out to theoretically investigate the mechanisms of direct regioselective phosphonation of heteroaryl N-oxides (A) with H-phosphonates (B1) under metal- and external oxidant-free conditions. The calculated results indicate that the reaction proceeds through two stages including nucleophilic addition of H-phosphonate to heteroaryl N-oxide (A) and the dehydration. Starting from the reactant B1 or its tautomer B2, two possible pathways have been suggested and studied in the first stage. Moreover, three possible channels including B1-assisted dehydration, B2-assisted dehydration, and direct dehydration have been investigated and compared in the second stage. Based on the computational results, we can conclude that both pathways associated with B1 and B2 are possible to occur under the experimental condition, and the B1/B2-assisted dehydration would have lower barriers than the direct dehydration. This work should be helpful for understanding the detailed mechanism of the title reaction, and thus provide valuable insights into rational design on the effective method/condition for this kind of reaction.

• 出版日期2015-11-1
• 单位河南理工大学; 郑州大学