Palladium Catalyzed\nC3-(sp<sup>2</sup>)‑H Alkenylation\nof Pyrroles via a Benzothiazole Directing Group: A Direct Access to\nOrganic Thermally Activated Delayed Fluorescence Materials

A Pd (II)-catalyzed direct C3-(sp<sup>2</sup>)-H alkenylation\nof\nheteroarenes using benzothiazole as a directing group was successfully\nachieved. A wide range of 2-<i>N</i>-alkylpyrroles undergo\nan oxidative coupling with a variety of acrylates to furnish highly\nregio- and chemoselective E-alkenylation products at the C3 position.\nAn important intermediate complex has been isolated and characterized\nso as to have an insight into the mechanism. This convenient protocol\nproved to be practical to access thermally activated delayed fluorescence\nmaterials (TADF). These molecules proved to be blue-emitting TADF\nmaterials (∼ms lifetime). A detailed and systematic investigation\nhas been carried out to study the photophysical properties, and this\nhas been further validated by the time-dependent density functional\ntheory calculations.