Ni-catalyzed cascade coupling reactions: synthesis and thermally-activated delayed fluorescence characterization of quinazolinone derivatives

A nickel-catalyzed strategy for the synthesis of 1,3-diaryl-6H-pyrazino[2,1-b]quinazolin-6-one was developed. This method enabled us to access valuable pyrazino-fused quinazolinones with tolerance of many functional groups even at room temperature. The desired pyrazino-fused quinazolinones emit strongly in both solution and solid states. Furthermore, the thermally-activated delayed fluorescence (TADF) of 3a was investigated. This study provides an efficient synthetic route for the development of TADF-active pyrazino-fused quinazolinones, thus expanding the application range of this versatile molecular scaffold in optoelectronics.