However, [18F]fluoride ion cannot be used directly to replace
hydrogen at aryl or alkyl C–H groups. Electrophilic reagents, such as
[18F]fluorine gas [5] and [18F]acetyl hypofluorite [6], have been used
for this purpose, but these labeling reagents cannot be prepared in a
single step from cyclotron-produced [18F]fluoride ion