Amino acids as C-H acids Communication 6. Absolute configuration of (+)530- and (−)530-bis(N-salicylideneaminoacidato)cobaltate(III) ions and stereoselective effects in these compounds

Autor: Belokon', Yu. N., Belikov, V. M., Dolgaya, M. M., Kruman, I. I., Nikitina, S. B., Petrovskii, P. V.
Zdroj: Russian Chemical Bulletin; August 1973, Vol. 22 Issue: 8 p1779-1785, 7p
Abstrakt: 1We synthesized the complexes: K (+)530- and (-)530-bis[N-salicylidene-(S-valinato)]cobaltate(III), K (+)530- and (-)530-N-salicylideneglycinato-[N-salicylidene-(S-valinato)]cobaltate(III), and K (+)530- and (-)530-bis[N-3-methylsalicylidene-(S-alaninato)cobaltate(III), and characterized them via the NMR and UV spectra and the optical rotation dispersion curves.2.A study was made of the epimerization of the complexes under the influence of bases in water and active carbon in ethanol, and it was shown that for the salicylaldehyde derivatives the most favorable are the isomers with the absolute configuration of the complexes of the (+)530-series and an absolute R configuration of the amino acid.3.In the alkylation of the glycine fragment of K (+)530 and (-)530-N-salicyIideneglyeinato-[N-salicylidene-(S-valinato)]cobaltate(III) with acetaldehyde the asymmetric yield and the ratio of the threo: allo forms of threonine both depend on the degree of epimerization of the S-valine fragment in these compounds, which testifies to the presence of the mutual effect of the asymmetric centers in the studied complexes.4.From the circular dichroism curves of the (+)530-bis[N-salicylideneglycinato]cobaltate(III) ion in the UV region it was established that it has the absolute ? configuration, which is in agreement with the data obtained for the complexes of the (+)530-series by chemical methods.
Databáze: Supplemental Index
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