Organocatalytic Enantioselective Mannich Reaction: Direct Access to Chiral ß-Amino Esters.

An asymmetric Mannich reaction has been developed to generate chiral ß-amino esters in good yields with excellent enantiomeric excesses (ee, up to 99%) using a chiral bifunctional thiourea catalyst derived from (R,R)-cyclohexyldiamine. This is the first report on the addition of 3-indolinone-2-carboxylates to N-Boc-benzaldimines generated in situ from α-amidosulfones, which proceeds under mild conditions.