Highly enantioselective synthesis of 2,3-dihydro-1H-imidazo[2,1-a]isoindol-5(9bH)-ones via catalytic asymmetric intramolecular cascade imidization-nucleophilic addition-lactamization.

Highly enantioselective catalytic asymmetric intramolecular cascade imidization-nucleophilic addition-lactamization of N(1)-alkylethane-1,2-diamine with methyl 2-formylbenzoate catalyzed by a chiral phosphoric acid represents the first efficient method for the preparation of medicinally interesting chiral 2,3-dihydro-1H-imidazo[2,1-a]isoindol-5(9bH)-ones with high yields and excellent enantioselectivities. This strategy has been shown to be quite general toward various methyl 2-formylbenzoates.