title: Highly enantioselective nitroaldol reactions catalyzed by copper(II) complexes derived from substituted 2-(pyridin-2-yl)imidazolidin-4-one ligands.
abstract: Ten optically pure substituted 2-(pyridin-2-yl)imidazolidin-4-ones, 1a-d, 2a-4a, and 2b-4b, 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.
authors.affiliation: Institute of Organic Chemistry and Technology, Faculty of Chemical Technology, University of Pardubice, Pardubice, Czech Republic.
authors.forename: Illia
authors.initials: I
authors.lastname: Panov
authors.forename: Pavel
authors.initials: P
authors.lastname: Drabina
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Padelková
authors.forename: Petr
authors.initials: P
authors.lastname: Simůnek
authors.forename: Milos
authors.initials: M
authors.lastname: Sedlák