Brønsted acid (HNO3)-catalyzed tandem reaction of α-ketoesters and arylamines: efficient synthesis of 1,2-dihydroquinoline derivatives

A simple and convenient Brønsted acid (HNO3)-catalyzed tandem reaction of α-ketoesters with primary or secondary aromatic amines for the synthesis of polysubstituted 1,2-dihydroquinolines has been developed via a tandem process, which has the advantages of ready availability of catalyst, operation simplicity, atom efficiency as well as low toxicity. In particular, tricyclic dihydroquinolines, generally prepared with multi-processes, could also be constructed in this one-pot procedure.