Highly active and recyclable heterogeneous palladium catalyst derived from guar gum for fabrication of biaryl compounds

In this study, a novel highly efficient heterogeneous palladium catalyst (GG-Pd) was prepared using guar gum, which is an environmentally friendly, easily available, fairly cheap, and renewable natural bio-polymer. Detailed characterization of GG-Pd catalyst was successfully performed by FT-IR, TG/DTG, SEM, EDS, XRD, and ninhydrin test, and it was evaluated as a heterogeneous catalyst against Suzuki-Miyaura coupling reactions of a series of aryl halides with phenylboronic acid. Catalytic performance studies showed that GG-Pd efficiently catalyzed Suzuki cross coupling reactions under solvent-free media and for a very short reaction time (5 min). Moreover, reusability tests showed that GG-Pd catalyst could be reused at least ten times with a minor decrease of its catalytic performance. Additionally, it was found that palladium leaching from the designed support was very minimal. This study shows that GG-Pd catalyst is a very useful and highly stable heterogeneous catalyst for Suzuki-Miyaura coupling reactions in terms of high catalytic performance and recyclability. (C) 2019 Elsevier B.V. All rights reserved.