Dynamic Kinetic Resolution of Azlactones by a Chiral N, N-Dimethyl-4-aminopyridine Derivative Containing a 1,1'-Binaphthyl Unit: Importance of Amide Groups.

A dynamic kinetic resolution (DKR) of azlactones in the presence of benzoic acid and a binaphthyl-based N, N-4-dimethylaminopyridine (DMAP) derivative 1i having two amide groups at the 3,3'-positions of a binaphthyl unit is developed. The reaction proceeded smoothly with a wide range of azlactones to provide α-amino acid derivatives with good to high enantiomeric ratios (er's). A multigram-scale reaction (2.5 g) for the DKR of azlactone 2d was also demonstrated, and the resulting product was converted to unnatural α-amino acid 6d'.

Enantioselective Steglich Rearrangement of Oxindole Derivatives by Easily Accessible Chiral N,N-4-(Dimethylamino)pyridine Derivatives.

Chiral N,N-4-(dimethylamino)pyridine (DMAP) derivatives, which can be readily prepared by the Ugi multicomponent reaction in a one-pot manner, have been efficiently applied to the enantioselective Steglich rearrangement of oxindole derivatives to give the desired products bearing a quaternary carbon center in high yield (>98% yield) and with high enantioselectivity (up to 99:1 er).

One-pot sequential alcohol oxidation and asymmetric α-oxyamination in aqueous media using recyclable resin-supported peptide catalyst.

An efficient tandem reaction system was developed, in which primary alcohols were used for the oxidation to the corresponding aldehydes followed by an asymmetric α-oxyamination with a resin-supported peptide catalyst.

Efficient asymmetric alpha-oxyamination of aldehydes by resin-supported peptide catalyst in aqueous media.

The resin-supported peptide catalyst having the terminal five-residue Pro-d-Pro-Aib-Trp-Trp combined with polyleucine successfully catalyzed the asymmetric alpha-oxyamination of aldehydes in aqueous media. The secondary structure and the chirality sense of the hydrophobic polyleucine chain significantly affected both reactivity and enantioselectivity.