In this project two new ligands with different features and properties have bean grafted on the surface of silica for immobilization of palladium nano-particles. The synthesised catalysts were applied for Suzuki–Miyaura and Sonogashira reactions. This project was conducted in two parts. In the first step, silica was modified by 3-aminopropyltrimethoxysilane and cyanuric chloride. In the part one of the work N-Heterocyclic Carbene was used as the ligand. To prepared the carbene ligand, an ionic liquid was synthesized and then it was linked to the surface of modified silica. Eventually, synthesized palladium nano catalyst was prepared from the modified silica and palladium acetate. In second part of the work, L-Cysteine amino acid as ligand was used and linked to surface of the modified silica. Then similar to part one , palladium nano catalysis was coordinated with to the carrier ligand. Different techniques such as FT-IR, CHNS, BET, SEM, ICP and TEM were used for characterization of the catalysts. The catalytic performance was examined in the Suzuki and Sonogashira reactions. The products were analyzed by GC and GC-MS. Furthermore, the reaction conditions were optimized for the reactions. The catalysts showed excellent activity towards Suzuki and Sonogashira coupling. In Suzuki reaction, phenyl bronic acid was reacted with some aryl halids such as iodobenzene, bromobenzene, 4-bromonitrobenzene, 3-bromoanisole, chlorobenzene in 120 ° C for 12 h. Water and K 2 CO 3 were used as solvent and base respectively. The conversion was over 98 % for iodobenzene for two catalysts. The catalysts were also effective for Sonogashira coupling. In Sonogashira reaction, iodobenzene reacted with phenylacetylene in 80 ° C for 24 h. DMF:H 2 O (3:1) and NaOAc were used as solvent and base respectively. The reusability of the catalysts, were tested in the two reactions. The presence of the silica support makes the nano-particles resistant to aggregation and precipitation and also helps preserve their catalytic activity during the five cycles. The nano catalysts can be easily recovered and repeatedly reused without loss of activity.
