Chiral phase-transfer catalyzed intramolecular aza-Michael reactions for the asymmetric synthesis of isoindolinones

Asymmetric intramolecular aza-Michael reactions catalyzed by cinchoninium phase-transfer organocatalysts are used for the synthesis of optically active isoindolinones. Selected oligomeric cinchoninium salts proved to be efficient and selective catalysts for the intramolecular addition of alkenylated benzamide substrates. The resulting compounds are useful intermediates for the synthesis and development of benzodiazepine-receptor agonists.