Asymmetric synthesis of isoquinolinonaphthyridines catalyzed by a chiral Brønsted acid

A catalytic asymmetric method for the synthesis of chiral isoquino-linonaphthyridines has been developed. A chiral disulfonimide catalyzes a redox cyclization reaction between 2-methyl-3-alde-hydeazaarenes and 1,2,3,4-tetrahydroisoquinolines to deliver a range of isoquinolinonaphthyridines with good to high yields (up to 91%) and up to 92:8 er.