Bifunctional Ammonium Salt Catalyzed Asymmetric α-Hydroxylation of ß-Ketoesters by Simultaneous Resolution of Oxaziridines.

ABSTRACT

Chiral bifunctional urea-containing ammonium salts were found to be very efficient catalysts for asymmetric α-hydroxylation reactions of ß-ketoesters with oxaziridines under base-free conditions. The reaction is accompanied by a simultaneous kinetic resolution of the oxaziridine and a plausible and so far unprecedented bifunctional transition-state model has been obtained by means of DFT calculations.