Theoretical investigation of von Braun and von Braun‐like reactions
Résumé
The von Braun reaction, discovered at the dawn of the past century, consists of the reaction between a tertiary amine and cyanogen bromide. It leads to the cleavage of a C-N bond with the formation of an N-dialkylcyanamide and an alkyl bromide and has been extensively used in organic synthesis. A detailed in silico study (PCM/DFT/B3LYP/6-31++G(d,p) calculations) of this venerable reaction has shown that in the first stage a zwitterionic adduct with a multi-bonded bromine atom is formed. The widely accepted mechanism involving an S N 2 reaction occurs in the second step, thus accounting for its selectivity. Quantum chemical calculations were performed for the von Braun-like reactions in systems formed by cyclic tertiary amines (N-alkyl azetidines). In these cases, the first stage is almost the same as in the classical von Braun processes, and selective S N 2 mechanisms can occur in the second step.
Domaines
| Origine | Fichiers produits par l'(les) auteur(s) |
|---|---|
| Licence |