Rhodium(iii)-catalyzed annulation of 3-arylquinazolinones with alkynes via double C–H activation: an efficient route for quinolino[2,1-b]quinazolinones

Abstract

An effective method for the synthesis of quinolino[2,1-b]quinazolinones has been described. The O-directing Rh(III)-catalyzed C–H activation of 3-arylquinazolinones and alkynes gave the corresponding polyaryl substituted quinolino[2,1-b]quinazolinones in good to excellent yields. The results of competition and isotope-labeling experiments support the proposed double C–H activation mechanism. The synthesized quinolino[2,1-b]quinazolinones exhibit a blue-colored emission and large Stokes shifts (67–123 nm) as well as emit visible fluorescence with good fluorescence quantum yields in the solid state.