Palladium-Catalyzed Thiazole-Directed mono-Selective C(sp2)-H Bond Iodination Reaction

A palladium-catalyzed ortho-C(sp(2))-H bond iodination of 4-arylthiazoles has been developed. Through screening of directing groups and optimazation of reaction parameters, the most efficient reaction conditions for mono-ortho-position iodination were obtained, which were applied to synthesize a series of 4-(2-iodoaryl)thiazoles with broad scope of 4-aryl-hiazole substrates. Furthermore, the iodine group can be easily transformed into other organic functional groups, which improved the application value of this methodology. At last, plausible mechanism was proposed based on an intermolecular deuterium labeling kinetic experiment and radical inhibition experiments.