High-Yield Room-Temperature Aryl 211At Radiolabeling via Redox-Activated Column-Shipped 211At

Abstract

Efficient late-stage formation of aryl–²¹¹At bonds is relevant to expanding the scope of targeted α-therapy radiopharmaceuticals. In this work, a catalyst-enabled astatodeboronation approach is evaluated using wet chemically regenerated ²¹¹At recovered from shipped 3-octanone-impregnated columns. A series of aryl boronic esters bearing electron-donating and electron-withdrawing substituents were radiolabeled under mild conditions, with reaction parameters examined through time-dependent studies. Radiochemical conversions ranging from 68–97% were observed across the substrate set. Density functional theory calculations were employed as a qualitative framework to contextualize relative B–C and At–C bonding descriptors. Overall, this study demonstrates that wet chemically regenerated ²¹¹At can be applied to the late-stage labeling of aryl boronic esters under mild conditions and provides guidance for future exploration of ²¹¹At radiolabeling strategies.