Diastereoselective and enantioselective capture of chiral zinc enolate using nitroolefins: a rapid access to chiral γ-nitro carbonyl compounds.

Highly diastereoselective and enantioselective catalytic capture of chiral zinc enolates using nitroolefins as electrophiles is described. The tandem products γ-nitro ketones were obtained in good yields with high diastereoselectivities and enantioselectivities. The γ-nitro ketones were readily hydrogenated to the optically enriched and diastereomerically pure chiral pyrrolidines with four contiguous stereocentres under mild conditions.

Asymmetric aldol reactions of α,ß-unsaturated ketoester substrates catalyzed by chiral diamines.

Highly efficient asymmetric aldol reactions between α,ß-unsaturated keto esters and acyclic ketones catalyzed by chiral diamines are reported. The corresponding products were obtained in excellent yields with excellent enantioselectivities. The absolute configuration for the product was determined by X-ray analysis. A variety of substrates were tolerable in the present catalytic system.

(2R,3R)-1-(4-Chloro-phen-yl)-2-[(S)-2-nitro-1-phenyl-eth-yl]-3-phenyl-pentan-1-one.

The title compound, C(25)H(24)ClNO(3), has three contiguous chiral centres. The absolute structure was determined by anomalous dispersion. The chloro-benzene ring is inclined to the two phenyl rings by 14.98 (9) and 59.05 (9)°. The two phenyl rings are inclined to one another by 49.51 (10)°. In the crystal, neighbouring mol-ecules are linked via C-H⋯O hydrogen bonds, forming chains propagating along [010]. There is also a C-H⋯π inter-action present that leads to the formation of a three-dimensional network.