High yield [125I]iodide-labeling of iodinated carboranes by palladium-catalyzed isotopic exchange

We have recently shown the feasibility of palladium-catalyzed isotopic exchange between [125I]iodide and 2-iodo-para-carborane. In this work we have modified the methodology and extended its application to a wider range of iodinated carboranes. Thus, by using Herrmannʹs catalyst in toluene at 100 °C, 2-I-p-, 3-I-o-, 9-I-o-, 9-I-m-carborane, 1-phenyl-3-I-o-carborane and 1,2-diphenyl-3-I-o-carborane have been radiolabeled with 125iodine in high to excellent yields.