Green and Efficient Procedure for Suzuki-Miyaura and Mizoroki-Heck Coupling Reactions Using Palladium Catalyst Supported on Phosphine Functionalized ZrO2 NPs (ZrO2@ECP-Pd) as a New Reusable Nanocatalyst

In this article, palladium supported on phosphine functionalized ZrO2 NPs (ZrO2@ECP-Pd) has been introduced as a novel and efficient nanocatalyst for Suzuki-Miyaura and Mizoroki-Heck reactions. This new catalyst was prepared from the reaction of Pd(OAc)(2) and PPh2-functionalized ZrO2 NPs, and then characterized using FT-IR, XRD, SEM, TEM, TGA and ICP techniques. The above experimental results showed that the synthesized catalyst existed as spheres with a mean size range of 10-40nm. The prepared ZrO2@ECP-Pd nanocatalyst was shown to be highly efficient in the SuzukiMiyaura and Mizoroki-Heck cross-coupling reactions of a wide range of aryl halides including electron-rich and electron poor aryl iodides/bromides, and heteroaryl iodides, affording the corresponding products in good to excellent yields in short reaction times. The notable feature of the present protocol is the use of water and [bmim]PF6 as environmentally benign solvents, which eliminate the need of toxic solvent. In addition to the aforementioned favorable properties, the nanocatalyst can be recovered and reused for the subsequent reactions (at least six times) without any appreciable loss of efficiency.