Highly Enantioselective Nitroaldol Reactions Catalyzed by Copper(II) Complexes Derived from Substituted 2-(Pyridin-2-yl)imidazolidin-4-one Ligands

• Published in: Journal of organic chemistry 2011-06, Vol.76 (11), p.4787-4793
• Main Authors: Panov, Illia, Drabina, Pavel, Padělková, Zdeňka, Šimůnek, Petr, Sedlák, Miloš
• Format: Article
• Language: English
• Subjects: Catalysis; Catalysts: preparations and properties; Chemistry; Exact sciences and technology; General and physical chemistry; Heterocyclic compounds; Heterocyclic compounds with only one n hetero atom and condensed derivatives; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; Kinetics and mechanisms; Organic chemistry; Preparations and properties; Reactivity and mechanisms; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo200703j

Ten optically pure substituted 2-(pyridin-2-yl)imidazolidin-4-ones, 1a–d, 2a–4a, and 2b–4 b, were prepared and characterized. The absolute configurations of individual ligands were determined by X-ray analysis or NOESY experiments. The Cu(II) complexes of the respective ligands were studied as enantioselective catalysts of the nitroaldol (Henry) reaction of aldehydes with nitromethane, giving the corresponding substituted 2-nitroalkanols. In the case of an anti arrangement of the imidazolidin-4-one ring, the obtained result was 91–96% ee, whereas in the case of syn arrangement, a significant drop to 25–27% ee was observed.