Rapid construction of C4-substituted phenanthridinones through palladium-catalyzed domino N-arylation/aryl-aryl coupling process

Abstract

• A novel palladium catalysis to prepare C4-substituted phenanthridinones via N-arylation/aryl-aryl coupling. • Excellent chemo- and regioselectivity, functional group tolerance and moderate to excellent yield. • Further late-stage diversification of products for the synthesis of multiple-substituted phenanthridinones. An excellent chemo- and regioselective palladium-catalyzed cascade intermolecular N -arylation/aryl-aryl coupling process has been developed. Employing Pd(TFA) 2 , PCy 3 •HBF 4 , K 2 CO 3 and 1,4-dioxane in an oil bath at 100°C for 12 h, diverse C4-substituted phenanthridinones are synthesized from o -bromobenzamides in 42-92% yield. Broad substrate scope and excellent functional group tolerance are observed. The synthetic utility of this method is illustrated by the further derivatization to prepare multiple-substituted phenanthridinones in 30-75% yield.