Metathesis reactions represent powerful synthetic tools that have been used in a number of fields from the synthesis of natural product to functional material preparation. However, the C–H metathesis reaction is extremely rare. Herein, we report the first Pd(II)-catalyzed C–H iodination of arenes using 2-nitrophenyl iodides as the mild iodinating reagents via a formal metathesis reaction. Unusual C–I bond formation occurred with aryl iodides in preference to competing C–C coupling in this reaction. Assisted by aliphatic carboxyl directing groups, a range of hydrocinnamic acids and related arenes could be selectively iodinated at either meta- or ortho-positions of the phenyl ring. Remote diastereoselective C–H activation was also promising. This method might unfold a novel approach to iodinate challenging substrates.

复分解反应代表了强大的合成工具，已用于从天然产物合成到功能材料制备的许多领域。然而，C-H复分解反应极为罕见。在此，我们报告了使用 2-硝基苯基碘化物作为温和碘化试剂通过正式复分解反应对芳烃进行 Pd(II) 催化的 C-H 碘化。在该反应中，芳基碘优先于竞争性 C-C 偶联，形成不寻常的 C-I 键。在脂肪族羧基导向基团的帮助下，一系列氢化肉桂酸和相关芳烃可以在间位或邻位选择性碘化-苯环的位置。远程非对映选择性 C-H 激活也很有希望。这种方法可能会展开一种新的方法来碘化具有挑战性的底物。