Preparation Of Supported Palladium Catalyst And Its Application Of One-pot Reductive Amination Reaction, Suzuki Reaction And Hydrogenation Reaction

Palladium (Pd) is arguably the most versatile and ubiquitous metal in modern organic synthesis. Palladium-mediated processes have become essential tools, spanning countless applications in the syntheses of natural products, polymers, agrochemicals, and pharmaceuticals. Pd-catalyzed C-C bond and C-N bond formation has become the research focus of the catalytic chemistry and synthetic organic chemistry. In this thesis, we study about preparation of supported palladium catalyst and its application in one-pot reductive amination reaction. Suzuki reaction and the hydrogenation reaction. And the work is been divided into three parts:The first part of this article about a high-performance palladium-based catalyst has been prepared by the co-precipitation method. The catalyst was characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), vibrating sample magnetometer (VSM) and nitrogen physical adsorption-desorption. It was found that the catalyst showed a high activity for the one-pot direct reductive amination of aldehydes with nitroarenes in the presence of molecular hydrogen in ethanol, even at room temperature. Furthermore, the catalyst was easily recovered by applying an external magnet and reused for eight cycles without significant loss of activity.In the second part, we explore the synthesis of a new palladium (II) bound heterogeneous catalyst through functionalization of 3D-hexagonally ordered SBA-16 type material with 3-aminopropyltriethoxysilane followed by the grafting with 2-acetylpyridine. Inductively coupled plasma (ICP), small-angle X-ray diffraction (XRD). transmission electron microscopy (TEM), nitrogen physical adsorption and fourier transform infrared (FTIR) studies have been used to characterize the catalyst. The catalyst exhibited very high activity for Suzuki coupling reaction of aryl halides with arylboronic acids in EtOH/water under air atmosphere. On the other hand, the synthesized catalyst could be separated from the reaction mixture by simple filtration and reused up to five runs without significant loss in activity.The third part of this article about the synthesis of a heterogeneous catalyst through functionalization of SBA-15 mesoporous material with 3-aminopropyltriethoxysilane followed by the grafting with palladium chloride and subsequent reduction with sodium borohydride. The catalyst was characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and fourier transform infrared (FTIR). It was found that the catalyst showed a high activity for the hydrogenation of various aromatic nitro. The catalyst was easily recovered by simple filtration and reused for eight cycles without significant loss of activity.