| Autor: |
Hensinger, Magenta J., Eitzinger, Andreas, Trapp, Oliver, Ofial, Armin R. |
| Předmět: |
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| Zdroj: |
Chemistry - A European Journal; 1/8/2024, Vol. 30 Issue 2, p1-9, 9p |
| Abstrakt: |
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. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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