Synthesis of geminal difluorides by oxidative desulfurization-difluorination of alkyl aryl thioethers with halonium electrophiles in the presence of fluorinating reagents and its application for 18F-radiolabeling.
Various ω-substituted 1,1-difluoroalkanes are synthesized in good yields from alkyl aryl thioethers by a new oxidative desulfurization-difluorination protocol with the reagents combination of 1,3-dibromo-5,5-dimethylhydantoin (DBH) as an oxidizer and pyridine·9HF (Py·9HF) as a fluoride source. The reaction proceeds via a fluoro-Pummerer-type rearrangement followed by an oxidative desulfurization-fluorination step. Starting from α-fluorinated thioethers, this reaction is promising for (18)F-labeling (τ(1/2) = 110 min) of ligands applicable for positron emission tomography (PET). Using the combination of DBH and carrier-added Py·9H[(18)F]F, an (18)F-labeled difluoride was synthesized from the corresponding α-fluoro thioether with a radiochemical yield of 9%.
Hugenberg
Verena
V
Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, D-48149 Münster, Germany.
Wagner
Stefan
S
Kopka
Klaus
K
Schober
Otmar
O
Schäfers
Michael
M
Haufe
Günter
G
D005462:Fluorine Radioisotopes / Q000737:chemistry*; D054879:Halogenation; D006845:Hydrocarbons, Fluorinated / Q000138:chemical synthesis* / Q000737:chemistry; D006858:Hydrofluoric Acid / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D011725:Pyridines / Q000737:chemistry*; D013237:Stereoisomerism; D013440:Sulfides / Q000737:chemistry*
D005462:Fluorine Radioisotopes; D006845:Hydrocarbons, Fluorinated; D011725:Pyridines; D013440:Sulfides; C023666:pyridine; D006858:Hydrofluoric Acid