A DFT Study on the Molecular Mechanism of Additions of Electrophilic and Nucleophilic Carbenes to Non-Enolizable Cycloaliphatic Thioketones.
Molecules
; 26(18)2021 Sep 13.
Article
em En
| MEDLINE
| ID: mdl-34577032
ABSTRACT
The molecular mechanisms of addition of dihalocarbenes and dimethoxycarbene to thioketones derived from 2,2,4,4-tetrmethylcyclobutane-1,3-dione were examined on the basis of the DFT wb97xd/6-311g(d,p)(PCM) calculations. Obtained results demonstrated that the examined processes exhibit polar nature and in the case of electrophilic dichloro-, and dibromocarbenes are initiated by the attack of carbene species onto the sulfur atom of the C=S group. Remarkably, reactions involving more electrophilic carbenes (dichloro-, and dibromocarbene) proceeds via stepwise mechanism involving thiocarbonyl ylide as a transient intermediate. In contrast, analogous reactions with nucleophilic dimethoxycarbene occur via a single step reaction, which can be considered as the [2 + 1] cycloaddition reaction initiated by the attack onto the C=S bond. A computational study showed that difluorocarbene tends to react as a nucleophilic species and resembles rather dimethoxycarbene and not typical dihalocarbene species. Significantly higher reactivity of the thioketone unit in comparison to the ketone group, both present in 3-thioxo-2,2,4,4-tetramthylcyclobutanone molecule, was rationalized in the light of DFT computational study.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Molecules
Assunto da revista:
BIOLOGIA
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Polônia