Palladium-incorporated on magnetic nanocatalysts based on carbon quantum dotand metal-organic frameworks for promoting Suzuki cross-coupling reaction

Heterogeneous catalysis plays an important role in industrial chemical production. They arepreferred due to their robustness and lower operational cost, in particular through easier recovery separationfrom the products allowing chemical processes to be streamlined. Magnetic nanoparticles have attractedincreasing attention because of their unique magnetic properties and easy separation from the reactionmixture by magnetic decantation rather than filtration or centrifugation. Palladium-catalyzed C-C couplingreactions, specially, Suzuki-Miyaura [۱,۲] have received considerable attentionfor the construction of C-Cbond in organic synthesis. Classic methodologies for coupling reactions contained use of homogeneous Pdcatalysts along with co-catalysts and ligands. Moreover, disclosing new catalysts, which didn’t require use ofco-catalyst and ligand and could promote the reactions in non-toxic solvents, has attracted intensive attention.In the following our study and research group [۳,۴], herein, we describe the synthesis of biphenyl derivativesby using MIL(۵۳)Fe@CQDs@Pd catalyst. This catalyst was synthesized through multi-step procedure. First,the magnetic MIL(۵۳)Fe was synthesized by hydrothermal method using FeCl۳.۶H۲O, FeCl۲.۴H۲O andNH۳.H۲O. On the other hand, carbon quantum dot was synthesized through carbonization of urea and p-aminosulfonic acid in a furnace at ۴۵۰ ° C for ۴ and a half hours. At the end, the final catalyst was achieved byincorporation of Pd(OAc)۲ on the surface of MIL(۵۳)Fe@CQDs that it was prepared via physical reaction ofMIL(۵۳)Fe and carbon quantum dot in an autoclave. The MIL(۵۳)Fe@CQDs@Pd catalyst was fullycharacterized by FT-IR, XRD, RAMAN, SEM, EDX, TEM, TGA, and ICP-AES analysis. TheMIL(۵۳)Fe@CQDs@Pd has been found to be an efficient and magnetically separable heterogeneous catalystfor Suzuki–Miyaura coupling reaction at a low amount (۰.۰۳g of MIL(۵۳)Fe@CQDs@Pd) under mild reactionconditions (۷۵-۱۰۰%), Scheme ۱. The nanocatalyst could be easily recovered from the reaction mixture byusing an external magnet and recycled up to five times without significant decrease in its catalytic activity.