Palladium Nanoparticles Supported on Aminopropyl-Functionalized Clay as Efficient Catalysts for Phosphine-Free C-C Bond Formation via Mizoroki-Heck and Suzuki-Miyaura Reactions

In this study, we have used palladium nanoparticles supported on aminopropyl-functionalized clay as an efficient catalyst for Mizoroki-Heck and Suzuki-Miyaura reactions. By using this catalyst, the reaction of iodo- and bromoarenes with n-butyl acrylate and styrene proceeded well and smoothly to produce the desired products in good to excellent yields under solvent-free conditions. The catalyst has been recycled for ten runs without much loss of its catalytic activity. Suzuki-Miyaura reaction of structurally different aryl halides (I and Br) with phenylboronic acid by the aid of this catalyst in refluxing water or SDS micellar solution in the absence of any organic co-solvent was also performed well to give the desired biphenyl products in good to excellent yields. Production of the corresponding homocoupled products in negligible amounts was observed in these reactions. In comparison with many other reported palladium-catalyzed Mizoroki-Heck and Suzuki-Miyaura reactions, the Pd-loading of this catalyst is one of the lowest. In the presence of this catalyst, all the reactions proceeded without using any external phosphorus ligands.