Triacylamines with Cs symmetry have been explored in asymmetric organocatalysis, leading to the development of a novel catalytic enantioselective desymmetrization of prochiral triacylamines by methanolysis under the catalysis of chiral pseudopeptidic guanidine-guanidinium salt having a weakly coordinating anion. This organocatalytic methodology provides an effective approach to the synthetically useful chiral imide-esters with a 1,5-dicarbonyl moiety, and its synthetic potential has been manifested in the asymmetric synthesis of two GABA analogue drugs, (R)-Baclofen·HCl and (S)-Pregabalin.