The use of elemental fluorine for selective direct fluorinations

When fluorinations using elemental fluorine are carried out in a strong acid medium, the reaction is more easily controlled. The selectivity of the reactions is improved since the fluorination is carried out by an “electrophilic” fluorine. Suitable substrates are therefore relatively nucleophilic, such as benzenoid aromatics and beta-dicarbonyls. A range of aromatics as well as diketones and keto-esters have been synthesised which are otherwise difficult or expensive to obtain by conventional means.