Hexagonal Boron Nitride Supported N-Heterocyclic Carbene-Palladium(II): A New, Efficient and Recyclable Heterogeneous Catalyst for Suzuki-Miyaura Cross-Coupling Reaction

In this study, a new stable and powerful hexagonal boron nitride supportedN-heterocyclic carbene-palladium(II) complex (h-BN@NHC-Pd) heterogeneous catalyst was designed and synthesized. The structure of theh-BN@NHC-Pd heterogeneous catalyst was characterized by various techniques such as Fourier transform infrared spectra (FT-IR), ultraviolet-visible spectroscopy (UV-Visible), inductively coupled plasma-optical emission spectroscopy (ICP-OES), energy-dispersive X-ray spectroscopy (EDS), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller surface area analysis (BET). Then catalytic activity ofh-BN@NHC-Pd heterogeneous catalyst was studied in the Suzuki-Miyaura cross-coupling reactions between aryl halides and arylboronic acids in aqueous medium at room temperature. The effects of varying solvents, bases, temperature, time and catalytic ratios on the performance of the Suzuki-Miyaura cross-coupling reaction were investigated. Moreover,h-BN@NHC-Pd heterogeneous catalyst could be easily recovered through simple filtration or centrifugation method and could be reused five times without significant loss of its catalytic efficiency. Furthermore, stability of theh-BN@NHC-Pd heterogeneous catalyst after recycling was confirmed through FESEM and FT-IR techniques. Theh-BN@NHC-Pd heterogeneous catalyst shows remarkable advantages such as simplicity of operation, excellent yields, short reaction times, heterogeneous nature, easily separable and high stability without leaching. [GRAPHICS] .

Automated summary

A new h-BN@NHC-Pd heterogeneous catalyst was designed and synthesized, characterized by various techniques, and studied for its catalytic activity in Suzuki-Miyaura cross-coupling reactions. The catalyst showed excellent catalytic efficiency with easy recovery and high stability after multiple reuses. Overall, it has remarkable advantages such as simplicity of operation, high yields, short reaction times, and heterogeneity.