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.