The self-disproportionation of enantiomers (SDE) of α-amino acid derivatives: facets of steric and electronic properties

Autor: Tomomi Imai, Takuma Hosaka, Alicja Wzorek, Anna Kolbus, Karel D. Klika, Magdalena Marcinkowska, Vadim A. Soloshonok, Osamu Kitagawa
Rok vydání: 2018
Předmět:
Zdroj: Amino Acids. 51:283-294
ISSN: 1438-2199
0939-4451
DOI: 10.1007/s00726-018-2664-x
Popis: α-Amino acids (α-AAs) are in extremely high demand in nearly every sector of the food and health-related chemical industries and continue to be the subject of intense multidisciplinary research. The self-disproportionation of enantiomers (SDE) is an emerging and one of the least studied areas of α-AA or enantiomeric properties, critically important for their production and application. In the present work, we report a detailed study of the SDE via achiral, gravity-driven column chromatography for a set of N-acylated, N-carbonylated, N-fluoroacylated, and N-thioacylated α-amino acid esters. As well as thioacylation, attention was paid to the effect of altering the R group of the ester functionality, the side chain, or that of the acyl group attached to the amide nitrogen, whereby it was found that electron-withdrawing groups in the latter moiety had a pronounced effect on the magnitude and behavior of the resulting SDE phenomenon. Intriguingly, in the case of N-fluoroacylated derivatives, by favoring the formation of dimeric associates and effecting a strong bias toward homochiral associates over heterochiral associates, the SDE magnitude was greatly reduced contrary to intuitive expectations. Energy estimates resulted from DFT calculations.
Databáze: OpenAIRE
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