Enantioselective Construction of 3-Hydroxy Oxindoles via Decarboxylative Addition of β-Ketoacids to Isatins

The first highly enantioselective decarboxylative addition of beta-ketoacids to isatins mediated by a bifunctional tertiary amine-thiourea catalyst has been developed, allowing facile synthesis of biologically important 3-hydroxy oxindoles In good yields and excellent enantioselectivities. The method reported represents a valuable approach of utilizing beta-ketoacids as synthetic equivalents of aryl/alkyl methyl ketone enolates.