Stereoselective Synthesis of 12-Tetrazolyl Substituted ( E )-5 H -Quinazolino[3,2- a ]quinazolines via Sequential Ugi-Azide/Staudinger/aza-Wittig/Addition/Ag(I)-Catalyzed Cyclization.

A new efficient and stereoselective synthesis of 12-tetrazolyl substituted ( E )-5 H -quinazolino[3,2- a ]quinazolines via sequential Ugi-azide/Staudinger/aza-Wittig/addition/Ag(I)-catalyzed cyclization was developed. The four-component reactions of 2-azidobenzaldehyde, 2-(alkynyl)benzenamine, isocyanide, and trimethylsilyl azide gave Ugi-azide intermediates, which were subsequently treated with triphenylphosphine and isocyanate to produce 12-tetrazolyl substituted ( E )-5 H -quinazolino[3,2- a ]quinazolines in the presence of Ag(I) catalyst and K 2 CO 3 .