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.

The direct catalytic asymmetric aldol reaction is one of the most fundamental transformations in organic synthesis, and several efficient asymmetric methodologies for this reaction using chiral metal catalysts [1] and organocatalysts [2][3][4] have recently been developed, of which catalysis by proline [2, 3] and its derivatives [4] have been extensively explored. However, the reactivity and selectivity of some of these prolinecatalyzed aldol reactions have serious limitations because of the difficulty in structurally modifying proline. Furthermore, a substoichiometric amount of proline is often necessary to achieve reasonable yields in the direct aldol reaction of aldehydes with acetone. Also, proline is known to react with electron-deficient aromatic aldehydes to form iminium salts, which undergo decarboxylation, even at room temperature. [5] Such degradation may induce the significant retardation of the proline-catalyzed aldol reactions. In this context, we were interested in designing an artificial amino acid catalyst 1 that would not undergo undesirable degradation through decar-

A novel and robust binaphthyl-based amino acid was designed and successfully applied to the direct asymmetric aldol reaction. In some cases, this catalyst leads to higher yields and selectivities than the well-known proline catalyst. For instance, the direct asymmetric aldol reaction of acetone with 4-nitrobenzaldehyde in the presence of the binaphthyl-based amino acid catalyst proceeded smoothly to give the aldol adduct in 82% yield with 95% ee. This catalyst was also found to catalyze effectively the reactions of cyclic or unsymmetrical ketones to give the corresponding aldol adducts with excellent diastereo- and enantioselectivities.

The direct catalytic asymmetric aldol reaction is one of the most fundamental transformations in organic synthesis, and several efficient asymmetric methodologies for this reaction using chiral metal catalysts [1] and organocatalysts [2][3][4] have recently been developed, of which catalysis by proline [2, 3] and its derivatives [4] have been extensively explored. However, the reactivity and selectivity of some of these prolinecatalyzed aldol reactions have serious limitations because of the difficulty in structurally modifying proline. Furthermore, a substoichiometric amount of proline is often necessary to achieve reasonable yields in the direct aldol reaction of aldehydes with acetone. Also, proline is known to react with electron-deficient aromatic aldehydes to form iminium salts, which undergo decarboxylation, even at room temperature. [5] Such degradation may induce the significant retardation of the proline-catalyzed aldol reactions. In this context, we were interested in designing an artificial amino acid catalyst 1 that would not undergo undesirable degradation through decar-

Binaphthyl-based amino acids were prepared and applied for the direct asymmetric aminoxylation of aldehydes with nitrosobenzene. The reaction catalyzed by (S)-1e proceeded smoothly to give the aminoxylated product in good yield and enantioselectivity. This method represents a rare example of the direct asymmetric aminoxylation by a non-proline-type catalyst.