ORGN 132

The enantioselective nucleophile catalyzed rearrangement of N,O-dicarboxylated 1 to N,C-dicarboxylated 2 with chiral catalysts proceeded with good enantioselectivity albeit slowly.  In the present work, a significant rate enhancement is observed in the DMAP catalyzed rearrangement of N,O-dicarbonylated 1 (R₁ = Ac, R₂,R₃ = Me) to N,C-diacylated 2 compared to N,O-dicarboxylated 1 (R₁ = CO₂Ph, R₂ = OPh, R₃ = Me).  Selective, sequential oxygen then nitrogen functionalization of oxidoles to give differentially protected enol esters 1 will be presented.  Enantioselective variants of this rearrangement with chiral nucleophilic catalysts 3 will be discussed.