Organocatalytic Stereoselective Decarboxylative Addition of α‐Amido Malonic Acid Half Oxyesters to Isatins

Abstract

The stereoselective reaction of α‐amido‐substituted malonic acid half oxyesters (amido‐MAHOs) with isatins was developed. A cinchona alkaloid thiourea catalyst gave products bearing a tetrasubstituted stereogenic centre in high yields with high diastereo‐ and enantioselectivities (75‐99% yield, 83:17‐97:3 dr, 92:8‐99:1 er). The obtained products can be converted into some chiral compounds without loss of enantiopurity. Density functional theory (DFT) calculations were conducted to clarify the origin of stereoselectivities, and revealed that the first centre is set in the decarboxylation, the second in the protonation.