Development, scope and mechanisms of multicomponent reactions of asymmetric electron-deficient alkynes with amines and formaldehyde.
Based on the reactive behaviour of the substrates, two synthetic routes to polysubstituted pyrimidine derivatives are presented herein: 1) A catalyst-free multicomponent reaction of electron-deficient alkynes, aliphatic amines and formaldehyde and 2) Ag(I)-catalyzed synthesis of pyrimidines from electron-deficient alkynes, anilines and formaldehyde by a domino reaction. Under optimized conditions, the multicomponent reactions were accomplished with high regioselectivity and excellent yields. A computational study was carried out by using the B3LYP density functional theory to elucidate the mechanisms of the catalyst-free hydroamination reaction. Calculations showed the activation free energies of aliphatic amines were lower than those of anilines, which is consistent with the experimental results.
Cao
Hua
H
School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, PR of China.
Wang
Xiujun
X
Jiang
Huanfeng
H
Zhu
Qiuhua
Q
Zhang
Min
M
Liu
Haiyang
H