Cobalt-Catalyzed Isocyanide-Based Three-Component Cascade for the Synthesis of Quinazolines.

A Co-catalyzed cyclization reaction of isocyanides, azides, and amines to access quinazoline derivatives was described. This protocol features a high atom economy, mild reaction conditions, excellent yields, and a broad substrate scope. This cascade reaction involved three or four C-N bonds and the formation of one or two rings. The quinazolin-4(H)-imines obtained are proven to be versatile intermediates for further valuable transformations. It was also found that the cobalt catalyst could be isolated from the reaction mixture and reused.