Visible‐Light‐Catalyzed Ring‐Opening Halogenation of Spiro‐Dihydroquinazolinones Using Perhalogenated Methanes as Halogen Sources

Visible‐light‐catalyzed aromatization‐driven deconstructive bromination and chlorination of spiro‐dihydroquinazolinones are described, with perhalogenated methanes serving as halogenating agents. A series of remotely and site‐specifically bromoalkyl‐ and chloroalkyl‐substituted quinazolin‐4(3H)‐ones were obtained with moderate yields and functional‐group tolerance. A radical pathway involving nitrogen‐centered‐radical‐induced C─C bond cleavage and carbon–halogen bond formation is proposed for this transformation.