Copper‐Catalyzed Three‐Component Cascade Reaction of Benzaldehyde with Benzylamine and Hydroxylamine or Aniline: Synthesis of 1,2,4‐Oxadiazoles and Quinazolines

The analogous three‐component synthesis strategy for substituted 1,2,4‐oxadiazole and quinazoline derivatives from readily available benzaldehyde, benzylamine and hydroxylamine or aniline has been developed. Both the cascade reaction sequences involves nucleophilic addition of C−N bond, introduction a halogen donor, nucleophilic substitution and Cu(II)‐catalyzed aerobic oxidation. This synthesis methodology demonstrated good yields, broad substrate scope and oxygen as a green oxidant. Thus, this synthesis protocol provides strategies for the construction of substituted 1,2,4‐oxadiazole and quinazolines from readily and simple starting materials. magnified image