N-Heterocyclic carbene-catalyzed enantioselective Mannich reactions with [alpha]-aryloxyacetaldehydes

N-Heterocyclic carbenes (NHCs) have catalyzed a new Mannich-type reaction to form [beta]-amino acid derivatives in high yield and enantioselectivity. The activated ester products formed in situ have formed a variety of useful compounds including [beta]-amino acids, [beta]-amino amides and peptides.