Pd-catalyzed cyclodehydrohalogenation involving oxidative addition of aromatic C–Br or activated azaheteroaromatic C–Cl bonds and C (sp2)–H activation have been investigated at high reaction temperatures (180–200° C). This allowed the fast (10–30min) synthesis of a variety of azaheteroaromatic ring systems (dibenzo [f, h] phthalazine, dibenzo [f, h] cinnoline, benzofuro [2, 3-d] pyridazine, 5H-pyridazino [4, 5-b] indole, 7H-indolo [2, 3-c] quinoline ...
