The benzenediazonium salts are attacked by nucleophiles in the presence of copper (I) salts that act as a catalyst, obtaining a wide variety of products.

sandmeyer reactions

The fluorination of benzene is very difficult to control due to its exothermic nature. For this reason, the introduction of fluorine into the ring is done through the Schiemann reaction, which consists of the thermal decomposition of diazonium tetrafluoroborates.

schiemann reaction