Palladium-Catalyzed Carbonylative 3-Component Synthesis of Quinazolinones

Significance

Reported is a Pd-catalyzed 3-component synthesis of quinazolinones from o-iodo­anilines, carbon monoxide, and imidoyl chlorides. Optimization studies using a variety of palladium sources and mono- and bidentate phosphorus ligands showed Pd(OAc)₂/PPh₃ to be the best combination for highest yields. In terms of reaction scope, substituents (EWGs and EDGs) on the 4-position of o-iodoanilines give competent yields (66-74%) but lower than when no substituted o-iodoaniline was involved (91%). Aryl and alkyl groups on the N,C sides of imidoyl chlorides gave medium to excellent yields. But when electron-poor substituents (e.g., 2-furanoyl) were involved, higher temperature (150 ºC) or longer reaction time (72 h) might be needed. The scope of the reaction was modestly studied.