Recyclable palladium(II) imino-pyridine complex immobilized on mesoporous silica as a highly active and recoverable catalyst for Suzuki–Miyaura coupling reactions in aqueous medium

A new mesoporous silica supported palladium imino-pyridine complex was successfully prepared by attaching palladium acetates to a novel imino-pyridine ligand functionalized MCM-41. The as-prepared catalyst was characterized by ICP-AES, XRD, FTIR, SEM, and TEM. It was found to be an efficient catalyst for Suzuki–Miyaura coupling reactions in aqueous medium. The reactions of various aryl bromides with arylboronic acids could be carried out under aerobic and low Pd loading (0.1 mol %) conditions with good to excellent yields, and very low Pd leaching (<0.2 ppm) was detected. Moreover, the supported catalyst could be simply recovered and reused several times without significant loss of efficiency.