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.

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Various allylmalonates and other related compounds were selectively deallylated in the presence of a catalytic amount of a rhodium complex and an excess of triethylaluminum. Comparison of several phosphane (PPh 3 ) and BIAP (bis(imidazolonyl)pyridine) rhodium complexes showed that the latter are more active and general with respect to the structural diversity of the substrate then the former. It was shown that the role of triethylaluminum is not only to generate in situ a rhodium hydride, which is assumed to be the catalytically active species, but also to act as a Lewis acid to activate the carbonyl group of the substrate. Thus, the proposed mechanism of deallylation involves hydrorhodation of the double bond along with activation of the carbonyl group of the substrate by triethylaluminum followed by a sequence of bond formations and cleavages, furnishing an enolate and an alkene. The methodology provides an efficient and selective route to deallylation of allylmalonates under mild reaction conditions.