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

• Published in: Amino acids Vol. 51; no. 2; pp. 283 - 294
• Main Authors: Hosaka, Takuma, Imai, Tomomi, Wzorek, Alicja, Marcinkowska, Magdalena, Kolbus, Anna, Kitagawa, Osamu, Soloshonok, Vadim A., Klika, Karel D.
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.02.2019; Springer Nature B.V
• Subjects: acids; Amino acids; Analytical Chemistry; Biochemical Engineering; Biochemistry; Biomedical and Life Sciences; Carbonyls; Chemical industry; Chemistry; Chromatography; Column chromatography; Derivatives; Disproportionation; Enantiomers; energy; Esters; Food industry; Gravity; Life Sciences; Medical research; moieties; Multidisciplinary research; Neurobiology; Nitrogen; Organic chemistry; Original Article; Phase transitions; Proteomics; (Thio)acylated α-amino acid esters; Achiral column chromatography; Enantioenrichment/-depletion; Self-disproportionation of enantiomers (SDE); Molecular chirality; DFT calculations; N-(Thio)acylated α-amino acid esters
• ISSN: 0939-4451; 1438-2199; 1438-2199
• DOI: 10.1007/s00726-018-2664-x

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.