DFT study on the reaction of the α-amino acid anion catalyzed by the aldehyde: Decarboxylation vs. intramolecular CO2 transfer

► Using DFT to study the reaction of amino acid anion catalyzed by the aldehyde. ► Two pathways have been assumed: one is the decarboxylation; the other is the intramolecular CO2 transfer. ► The substituent without π-system promotes the intramolecular CO2 transfer. ► The substituent with π-system advances the direct decarboxylation.