Column-Shipped 211At for Targeted Alpha Therapy: High Radiochemical Conversion in Organotin Astatination via Redox Activation

Abstract

Astatine-211 is a rare heavy halogen radionuclide whose ability to form covalent carbon–astatine bonds confers distinctive chemical behavior, yet its broader application remains limited by tracer-level availability and complex aqueous speciation. Because production is restricted to a small number of specialized cyclotron facilities worldwide, direct on-site access is impractical for most research and clinical centers; accordingly, distribution from centralized production sites via column-based conveyance provides a practical strategy for expanding access to this promising α-emitter for targeted alpha therapy. This study demonstrates that oxidative activation of column-recovered 211At generates a reactive astatine species that enables efficient labeling of aryl-organotin precursors under mild, catalyst-free conditions. Structurally diverse substrates, including chloro-substituted arylstannanes, guanidyl-functionalized benzyl derivatives, and heteroaryl thiophenes, undergo rapid astatination with radiochemical conversions of 83–95%. This work establishes a practical and electronically tunable platform for 211At radiochemistry using column-shipped material, helping extend astatination chemistry beyond specialized cyclotron facilities.