Capturing aqueous [18F]-fluoride with an arylboronic ester for PET:: Synthesis and aqueous stability of a fluorescent [18F]-labeled aryltrifluoroborate

The aqueous stability of aryltrifluoroborates is of importance to their use in transition metal mediated coupling reactions as well as their potential use in [F-18]-labeled aryltrifluoroborate PET imaging agents. Nevertheless, few studies have fully characterized the solvolysis of fluoride from an aryltrifluoroborate in water. Using [F-19] NMR, fluorescence and [F-18]-labeling techniques, we disclose the composition of an aryltrifluoroborate of exceptional kinetic stability with respect to solvolytic defluoridation. This work not only highlights the potential of using [F-18]-labeled aryltrifluoroborates for PET tracers, but provides a chemical platform and a general approach for evaluating the stability of other aryltrifluoroborates. (c) 2008 Elsevier B.V. All rights reserved.