title: 18F-labeling using click cycloadditions.
abstract: Due to expanding applications of positron emission tomography (PET) there is a demand for developing new techniques to introduce fluorine-18 (t 1/2 = 109.8 min). Considering that most novel PET tracers are sensitive biomolecules and that direct introduction of fluorine-18 often needs harsh conditions, the insertion of (18)F in those molecules poses an exceeding challenge. Two major challenges during (18)F-labeling are a regioselective introduction and a fast and high yielding way under mild conditions. Furthermore, attention has to be paid to functionalities, which are usually present in complex structures of the target molecule. The Cu-catalyzed azide-alkyne cycloaddition (CuAAC) and several copper-free click reactions represent such methods for radiolabeling of sensitive molecules under the above-mentioned criteria. This minireview will provide a quick overview about the development of novel (18)F-labeled prosthetic groups for click cycloadditions and will summarize recent trends in copper-catalyzed and copper-free click (18)F-cycloadditions.
authors.affiliation: Institute of Nuclear Chemistry, Johannes Gutenberg University Mainz, 55128 Mainz, Germany.
authors.forename: Kathrin
authors.identifier: 0000-0003-1741-2864
authors.initials: K
authors.lastname: Kettenbach
authors.affiliation: Institute of Nuclear Chemistry, Johannes Gutenberg University Mainz, 55128 Mainz, Germany.
authors.forename: Hanno
authors.identifier: 0000-0001-7286-3380
authors.initials: H
authors.lastname: Schieferstein
authors.affiliation: Institute of Nuclear Chemistry, Johannes Gutenberg University Mainz, 55128 Mainz, Germany ; Radiopharmaceutical Chemistry, Department of Nuclear Medicine, Hannover Medical School, 30625 Hannover, Germany.
authors.forename: Tobias L
authors.initials: TL
authors.lastname: Ross
mesh_terms: D000818:Animals; D002384:Catalysis; D057930:Click Chemistry / Q000379:methods*; D003300:Copper / Q000737:chemistry; D061565:Cycloaddition Reaction; D005462:Fluorine Radioisotopes / Q000737:chemistry*; D013194:Staining and Labeling
chemical_list: D005462:Fluorine Radioisotopes; D003300:Copper