Aryl isocyanide derivative for one-pot synthesis of purification-free Tc-labeled hexavalent targeting probe.

Introduction: Tc-labeled hexavalent probes can be readily synthesized by the coordination of six equivalent isocyanide ligands towards Tc, and alkyl isocyanide ligands have been extensively used for preparing such probes. However, high ligand concentration (>1 mM) is generally required due to their insufficient coordination ability to Tc.

Methods And Results: In this study, we revealed that aryl isocyanide ligands, which have greater π-accepting ability compared with alkyl ones, provided Tc-labeled hexavalent probes in high radiochemical yields (>95%) even at low ligand concentration (50 μM).