[reaction: see text] The synthetic utility of chiral N-heterocyclic carbenes, which have been used mainly in transition metal-catalyzed reactions as a ligand, was demonstrated by the enantioselective acylation of secondary alcohols.

A titanium BINOLate catalyzed asymmetric 1,3-dipolar cycloaddition reaction between alpha-substituted acroleins and alkyl diazoacetates has been developed. With this methodology in hand, chiral 2-pyrazolines containing a quaternary stereogenic center were obtained in high to excellent enantioselectivities (up to 95% ee). The synthetic utility of the optically enriched 2-pyrazoline thus obtained was demonstrated in the short synthesis of manzacidin A.

A direct asymmetric Mannich reaction using a novel axially chiral amino trifluoromethanesulfonamide (S)-3 has been developed in highly anti-selective and enantioselective manners. Thus, in the presence of a catalytic amount of (S)-3, the reactions between aldehydes and the alpha-imino ester 4 proceed smoothly to give the functional beta-amino aldehydes with significantly higher anti/syn ratio and enantioselectivity than previously possible.

Optically active sulfoximines are a promising substance in medicinal chemistry. However, a methodology for preparing chiral sulfoximines in a stereoselective manner has been underdeveloped. Here, we report an asymmetric synthesis of chiral sulfoximines having an aryl group by the newly developed sulfurselective arylation of easily accessible chiral sulfinamides. The utility of the present method is demonstrated by the asymmetric synthesis of a key intermediate of a COX-2 inhibitor.

A direct asymmetric hydroxyamination reaction of aldehydes with nitrosobenzene was found to be catalyzed by the novel axially chiral secondary amine catalyst (S)-1d. The resulting optically enriched hydroxyamination products were readily converted to beta-amino alcohols or 1,2-diamines in one pot.