Radical bromination/cascade cyclization: a facile approach towards benzimidazole-fused isoquinolinones

Abstract

A radical bromination/cyclization strategy has been developed for the synthesis of brominated benzimidazo[2,1-a]isoquinolin-6(5H)-ones by utilizing tetrabutylammonium bromide (TBAB) as a safe and cheap bromide source. It demonstrates efficiency in the first reported construction of these brominated scaffolds with good functional group tolerance, enabling the direct introduction of a bromine atom which was suited for late-stage functionalization, underscoring its potential for further derivatization in the synthesis of complex molecules.