Polymer-Supported Pd Catalyst

Catalyst 1 is an amphiphilic polymer-supported palladium catalyst developed by Ikegami et al. This palladium catalyst can incorporate hydrophilic or hydrophobic substrates into the neighborhood of the palladium to give smooth reactivity. In addition, 1 can form a networked supramolecular complex. This compound is insoluble both in water and in organic solvents, making the catalyst easily recoverable from the reaction medium. Since palladium atom is firmly supported by the phosphino groups of the copolymer, it does not leak out during the reaction, making the catalyst available for repeated usage. As an application of 1, Ikegami et al. have used this catalyst in the Suzuki-Miyaura reaction. In this case, the reaction was carried out with a catalytic amount of 1 (5 × 10^-5 mol eq.) in water as solvent, with the turnover number reaching approximately 20,000. The catalyst was easily recovered by simple filtration and recycled 10 times without any loss of its activity.

Due to the environmental friendliness of this catalyst, it has gained much attention from the perspective of Green Chemistry, and its application has been expanded to various fields.