Mechanisms of water-promoted aryl azide conversion into N-alkylated aniline: Two competitive pathways

Abstract

The reaction mechanism for the conversion of aryl azide into N-alkylated aniline using Bu2BOTf as an alkylating agent has been unveiled by employing density functional theory (DFT) calculations at the B3LYP/6-31+G(d,p) level of theory and the reactivity indices like Fukui function and dual descriptor. The results show that the electrophilic attack of Bu2BOTf on aryl azide leads to the abscission of N2 via SN2 reaction, then the obtained intermediate goes through a critical step of hydrolytic procedure to generate the product. Water molecule play a crucial role in obtaining the product, the hydrolytic process can probably proceed via two competitive pathways I and II in which one and two water molecules are involved, respectively. Pathway II with CH2Cl2 as solvent is more favorable, which could be the actual reaction process to yield the product. The energy profile for the whole reaction indicates that it can be realized at room temperature, consistent with the experimental results.