Controllable direct arylation: fast route to symmetrical and unsymmetrical 4,7-diaryl-5,6-difluoro-2,1,3-benzothiadiazole derivatives for organic optoelectronic materials.

Arylation in the 4- and 7-positions of 2,1,3-benzothiadiazole (BT) and its monofluoro- (MFBT) and difluoro- (DFBT) derivatives by (hetero)aryl bromides using Pd-catalyzed C–H activation has been investigated. MFBT and DFBT can be diarylated in moderate to high yields (up to 96% for DFBT) by a variety of aryl bromides. DFBT can be sequentially arylated using two different aryl bromides to give differentially substituted DFBT derivatives. The moderate to high yields of doubly arylated MFBT and DFBT and the ability to obtain differentially substituted products can be applied to a variety of organic photonic and electronic materials.