Wydział Chemii

Ibrahim Mbouombouo Ndassa

Abel Idrice Adjieufack

Joseph Mbadcam Ketcha

Sławomir Berski

Mar Ríos-Gutiérrez

Luis R. Domingo

2017

International Journal of Quantum Chemistry

117

e25451/1-e25451/13

10.1002/qua.25451

Naukowa

Angielski

Artykuł

The [3 + 2] cycloaddition (32CA) reactions of three nitrile oxides (NOs) (R-CNO; R = Ph, CO₂Me, and Br) with methyl acrylate (MA) have been theoretically studied within the molecular electron density theory. Topological analysis of the electron localization function of these NOs permits to establish that they will participate in zw-type 32CA reactions. Analysis of the conceptual DFT indices indicates that these zw-type 32CA reactions will have a low polar character as a consequence of the relatively low electrophilic character of MA and the low nucleophilic character of NOs, in agreement with the global electron density transfer computed at the corresponding TSs. The activation enthalpies associated with these 32CA reactions range from 8.2 to 12.7 kcal·mol⁻¹. The presence of the bromide atom provokes the larger acceleration. While the 32CA reaction involving the CO₂Me substituted NO is highly ortho regioselective, the other two reactions are poorly ortho regioselective. A bonding evolution theory study of the more favorable ortho regiosiomeric channel associated with the 32CA reaction involving the Br substituted NO indicates that this reaction is associated to a nonconcerted two-stage one-step mechanism, in which the activation energy is mainly related to the initial rupture of the CN triple bond of the NO.

bonding evolution theory, [3 +2] cycloaddition reaction, electron localization function, molecular electron density theory

https://doi.org/10.1002/qua.25451

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