Synthesis Of Palladium Carboxymethylcellulose And Its Applications For Suzuki And Heck Coupling Reactions

The palladium-catalyzed coupling reaction is one of the most important methods for forming C-C bond. These coupling products were found widely applications as intermediates in the preparation of pharmaceuticals, pesticides, polymer, daily-use chemical functional materials, and other industrial fields. Heterogeneous palladium catalyst systems were widely used for the formation of C-C bonds due to its displays apparently advantageous properties, such as high catalytic activity, stability, mild and green reaction conditions, easy recovery and reusability. The natural biopolymer and modified polymer were widely used as a carrier for the palladium loading. Aryl halide was commonly used as electrophilic reagent in palladium-catalyzed C-C coupling reaction. But in recent years, aryldiazonium tetrafluoroborate salts have also attracted much attention due to its easy preparation, high activity, low reaction temperature. We prepared the carboxymethylcellulose supported palladium catalyst via ion exchange with Pd Cl2 solution, and study its catalytic activity on Suzuki and Heck coupling reaction.1. We prepared the carboxymethylcellulose supported palladium catalyst through metathesis of palladium chloride with sodium carboxymethylcellulose in aqueous solution. The catalyst was found high catalytic activity and easy separation recycling for Suzuki and Heck coupling reactions.2. The carboxymethylcellulose supported palladium catalyst was also applied to Suzuki and Heck coupling reactions using aryldiazonium tetrafluoroborate salts. We found that the coupling reaction can be performed at room temperature, the yield was high, the reaction solvent was green, and the catalyst could be easy recovered and recycling.