Novel radiolabelling methods are important for the development of new tracers for positron emission tomography. Direct nucleophilic fluorination of aromatic rings with [18F]fluoride is limited to activated substrates, restricting the application of this approach. Inspired by transition metal-mediated transformations, a fluorine-18 synthon was prepared to supplement the radiolabelling methods available for molecules unsuitable for direct labelling. 2-Bromo-6-[18F]fluoropyridine (denoted [18F]1) was prepared in high yield, and palladium-mediated cross-coupling reactions were exemplified. High incorporation of fluoride and efficient cross-coupling reactions demonstrate that compound [18F]1 holds promise as a new synthon for construction of fluorine-18-labelled molecules via transition metal-mediated reactions.
新的放射性标记方法对正电子发射断层扫描新示踪剂的开发至关重要。芳香环的直接亲核
氟化与[18F]
氟化物的反应仅限于活性底物,限制了该方法的应用。受到过渡
金属介导转化的启发,制备了一种
氟-18合成子,以补充不适合直接标记的分子的放射性标记方法。高产率制备了2-
溴-6-[18F]
氟吡啶(记作[18F]1),并示范了
钯介导的交叉偶联反应。
氟的高引入率和高效的交叉偶联反应表明,化合物[18F]1作为通过过渡
金属介导反应构建
氟-18标记分子的新合成子具有良好的前景。