Theoretical study on the hypervalent λ3-bromane strategy for Baeyer-Villiger oxidation of benzaldehyde and acetaldehyde: rearrangement mechanism.
The rearrangement mechanisms of the novel Baeyer-Villiger oxidation (BVO) of benzaldehyde and acetaldehyde have been studied using density functional theory methods. All structures associated with the product formation step of the new Criegee intermediate, α-hydroxyalkoxy-λ(3)-bromane, are reported. B3LYP/6-31++G** calculations give a good description for the group shift of these two typical reactants: phenyl shift is easier than hydrogen shift for benzaldehyde; hydrogen migration is more favorable than methyl migration for acetaldehyde. Different mechanisms and various conformers of the novel BVO reaction have been considered for the migration step. Solvent effects and rate constants are also taken into account. The calculated and experimentally observed branching ratios are in good agreement with each other.
State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Shandong, Qingdao 266555, People's Republic of China. fuhui@upc.edu.cn
Hui
H
Fu
Shouwen
S
Xie
Aiping
A
Fu
Xufeng
X
Lin
Hui
H
Zhao
Tianxu
T
Ye