Targeted Fluorination with the Fluoride Ion by Manganese-Catalyzed Decarboxylation

We describe the first catalytic decarboxylative fluorination reaction based on the nucleophilic fluoride ion. The reported method allows the facile replacement of various aliphatic carboxylic acid groups with fluorine. Moreover, the potential of this method for PET imaging has been demonstrated by the successful F-18 labeling of a variety of carboxylic acids with radiochemical conversions up to 50%, representing a targeted decarboxylative F-18 labeling method with no-carrier-added [F-18] fluoride. Mechanistic probes suggest that the reaction proceeds through the interaction of the manganese catalyst with iodine(III) carboxylates formed in situ from iodosylbenzene and the carboxylic acid substrates.