Enantioselective synthesis of tricyclic oxoquinolines via NHC-catalyzed Michael-aldol-lactamization-dehydration cascade.

The enantioselective synthesis of tricyclic oxoquinolines via NHC-catalyzed cascade reaction of enals with malonates bearing a 2-aminophenyl group is reported. The chiral α,β-unsaturated acylazoliums underwent a smooth Michael-aldol-lactamization-dehydration quadruple cascade with the amino malonate derivative to afford the desired tricyclic products.