Access to N-Fused Quinazolinones by Radical-Promoted Cascade Annulations of Alkenyl N -Cyanamides with Aromatic Aldehydes.

A cascade radical cyclization of alkenyl N -cyanamides with aromatic aldehydes has been achieved for an expeditious synthesis of keto-methylated dihydropyrrolo-quinazolinones. Benzoyl radicals, generated from aryl aldehydes in the presence of di- tert -butyl peroxide (DTBP), promoted the domino annulations leading to distinctive functionalized quinazolinones in good yields. In addition, the robustness of the present protocol is validated by employing heterocyclic and natural product-based aldehydes.