Nucleophilicity of 4-(Alkylthio)-3-imidazoline Derived Enamines.
Chemistry
; 30(2): e202302764, 2024 Jan 08.
Article
en En
| MEDLINE
| ID: mdl-37850416
ABSTRACT
Imidazolidine-4-thiones (ITOs) are cyclic, secondary amines that were considered as potential prebiotic organocatalysts for light-driven α-alkylations of aldehydes by bromoacetonitrile (BAN). Recent studies showed that the initially supplied ITOs represent the pre-catalyst because they undergo S-alkylation with BAN to give 4-(alkylthio)-3-imidazolines (TIMs). Given that the same reagent mix that undergoes light-driven α-alkylations is also effective in the dark, we synthesized ten ITO- or TIM-derived enamines of aldehydes and characterized their nucleophilic reactivities by kinetic studies in acetonitrile. The experimental second-order rate constants k2 for reactions of enamines with benzhydrylium ions (reference electrophiles) were evaluated by the Mayr-Patz equation, lg k2 (20 °C)=sN (N+E). The determined nucleophilicities N (and sN ) reveal the reactivity profiles of these enamines under prebiotically relevant conditions as well as their potential for use in organocatalytic synthesis.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Chemistry
Asunto de la revista:
QUIMICA
Año:
2024
Tipo del documento:
Article
País de afiliación:
Alemania
Pais de publicación:
ALEMANHA
/
ALEMANIA
/
DE
/
DEUSTCHLAND
/
GERMANY