Direct C-H Fluorination of N-Heterocycles Promoted by Transition Metals in High Oxidation State

A method for obtaining of monofluoro N-heterocycles (pyridines, benzazoles) in the presence of salts of transition metals (nickel, cobalt or silver) in high oxidation states under electrochemical catalytic oxidative conditions is developed. Electrochemical reactions are shown to be effective for the C-H functionalization of heterocyclic substrates. Monitoring of the reaction progress under electrochemical conditions provides mechanistic insight into the C-H functionalization of a heterocycles, which are of interest in medicinal chemistry. It was demonstrated that the electrochemical fluorination results either in 2-fluoro-, or 3-fluorine pyridine depending on the used catalyst.