A Dimeric Thiourea CSA for the Enantiodiscrimination of Amino Acid Derivatives by NMR Spectroscopy
| Autor: | Gloria Uccello-Barretta, Alessandra Recchimurzo, Cosimo Micheletti, Federica Balzano |
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| Rok vydání: | 2021 |
| Předmět: |
Magnetic Resonance Spectroscopy
010405 organic chemistry Hydrogen bond Organic Chemistry Molecular Conformation Stereoisomerism Amino Acids Thiourea Diastereomer Ethylenediamine DABCO Nuclear magnetic resonance spectroscopy Carbon-13 NMR 010402 general chemistry 01 natural sciences Medicinal chemistry Article 0104 chemical sciences chemistry.chemical_compound chemistry Enantiomer |
| Zdroj: | The Journal of Organic Chemistry |
| ISSN: | 1520-6904 0022-3263 |
| DOI: | 10.1021/acs.joc.1c00340 |
| Popis: | The reaction of benzoyl isothiocyanate with (1R,2R)-1,2-bis(2-hydroxyphenyl)ethylenediamine afforded a new thiourea chiral solvating agent (CSA) with a very high ability to differentiate 1H and 13C NMR signals of simple amino acid derivatives, even at low concentrations. The enantiodiscrimination efficiency was higher with respect to that of the parent monomer, a thiourea derivative of 2-((1R)-1-aminoethyl)phenol, thus putting into light the relevance of the cooperativity between the two molecular portions of the dimer in a cleft conformation stabilized by interchain hydrogen bond interactions. An achiral base additive (DABCO or DMAP) played an active role in the chiral discrimination processes, mediating the interaction between the CSA and the enantiomeric mixtures. The chiral discrimination mechanism was investigated by NMR spectroscopy through the determination of complexation stoichiometries, association constants, and the stereochemistry of the diastereomeric solvates. |
| Databáze: | OpenAIRE |
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