The present invention relates to a process for producing an organic compound comprising an 18F atom. The compounds comprising an 18F can be useful as PET ligands for use in diagnostics and/or scanning. The process of the invention comprises treating an organoboron compound, which organoboron compound comprises a boron atom bonded to an sp2 hybridised carbon atom, with (i) 18F – and (ii) a copper compound. The invention also provides the use of an organoboron compound, which organoboron compound comprises a boron atom bonded to an sp2 hybridised carbon atom, in a process for producing an organic compound comprising an 18F atom, which process comprises treating the organoboron compound with (i) 18F – and (ii) a copper compound. The invention also provides a compound of formula (XXXVII): wherein: each PGA is independently H or an alcohol protecting group; PGB is H or a carboxylic acid protecting group; each PGC is independently an amine protecting group; Z is a group selected from a boronic ester group, a boronic acid group, a borate group, and a trifluoroborate group; and a is an integer from 0 to 4.