Base-controlled selectivity in the synthesis of linear and angular fused quinazolinones by a palladium-catalyzed carbonylation/nucleophilic aromatic substitution sequence

Abstract

A new approach for the facile synthesis of fused quinazolinone scaffolds through a palladium-catalyzed carbonylative coupling followed by an intramolecular nucleophilic aromatic substitution is described. The base serves as the key modulator: Whereas DBU gives rise to the linear isomers, Et3N promotes the preferential formation of angular products. Interestingly, a light-induced 4+4 reaction of the product was also observed.

Keywords: carbonylation; domino reactions; nucleophilic aromatic substitution; palladium catalysts; quinazolinones.