Unexpected Behavior of the Heaviest Halogen Astatine in the Nucleophilic Substitution of Aryliodonium Salts - Inserm - Institut national de la santé et de la recherche médicale Accéder directement au contenu
Article Dans Une Revue Chemistry - A European Journal Année : 2016

Unexpected Behavior of the Heaviest Halogen Astatine in the Nucleophilic Substitution of Aryliodonium Salts

Résumé

Aryliodonium salts have become precursors of choice for the synthesis of 18 F-labeled tracers for nuclear imaging. However, little is known on the reactivity of these compounds with heavy halides, that is, radioiodide and asta-tide, at the radiotracer scale. In the first comparative study of radiohalogenation of aryliodonium salts with 125 I À and 211 At À , initial experiments on a model compound highlight the higher reactivity of astatide compared to iodide, which could not be anticipated from the trends previously observed within the halogen series. Kinetic studies indicate a significant difference in activation energy (E a = 23.5 and 17.1 kcal mol À1 with 125 I À and 211 At À , respectively). Quantum chemical calculations suggest that astatination occurs via the monomeric form of an iodonium complex whereas iodi-nation occurs via a heterodimeric iodonium intermediate. The good to excellent regioselectivity of halogenation and high yields achieved with diversely substituted aryliodonium salts indicate that this class of compounds is a promising alternative to the stannane chemistry currently used for heavy radiohalogen labeling of tracers in nuclear medicine.

Domaines

Cancer
Fichier sous embargo
Fichier sous embargo
Date de visibilité indéterminée
Loading...

Dates et versions

inserm-01387016 , version 1 (25-10-2016)

Identifiants

Citer

François Guérard, Yong-Sok Lee, Kwamena Baidoo, Jean-François Gestin, Martin W Brechbiel. Unexpected Behavior of the Heaviest Halogen Astatine in the Nucleophilic Substitution of Aryliodonium Salts. Chemistry - A European Journal, 2016, 22 (35), pp.12332-9. ⟨10.1002/chem.201600922⟩. ⟨inserm-01387016⟩
101 Consultations
2 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More