Highly enantioselective α-aminoxylation of aldehydes and ketones with a polymer-supported organocatalyst

The first catalytic enantioselective alpha-aminoxylation of aldehydes and ketones using an insoluble, polymer-supported organocatalyst (1) derived from trans-4-hydroxyproline is reported (ee: 96-99%). Reaction rates in the aminoxylation of cyclic ketones with 1 are higher than those reported with L-proline. The insoluble nature of 1 simplifies workup conditions and allows catalyst recycling without an apparent decrease in enantioselectivity or yield.