Porous aromatic frameworks with high Pd nanoparticles loading as efficient catalysts for the Suzuki coupling reaction

Area of Science:

• Materials Science
• Catalysis
• Organic Chemistry

Background:

• Heterogeneous palladium (Pd) catalysts are crucial for organic synthesis and pharmaceutical production.
• Developing efficient and recyclable Pd catalysts remains a significant research focus.

Purpose of the Study:

• To synthesize and characterize novel heterogeneous Pd catalysts, Pd@PAF-182 and Pd@PAF-183.
• To evaluate their catalytic performance in Suzuki coupling reactions.
• To assess their recyclability and stability.

Main Methods:

• Synthesis of porous aromatic frameworks (PAF-182, PAF-183) via Yamamoto-type Ullmann coupling.
• Immobilization and reduction of PdCl4(2-) to form Pd nanoparticles (Pd NPs) on PAFs.
• Characterization using PXRD, NMR, XPS, SEM, and TEM.
• Catalytic evaluation in Suzuki coupling reactions and recycling tests.

Main Results:

• High loading of Pd NPs (29.4 wt% for Pd@PAF-182, 37.5 wt% for Pd@PAF-183) achieved.
• Pd@PAFs efficiently catalyzed Suzuki coupling with yields up to 99% using only 0.12 mol% Pd NPs.
• Catalysts maintained high activity over five recycling cycles with negligible Pd leaching.

Conclusions:

• Pd@PAF-182 and Pd@PAF-183 are highly efficient and recyclable heterogeneous Pd catalysts.
• These catalysts offer a promising platform for sustainable organic synthesis.
• The high Pd loading and stability make them suitable for pharmaceutical production.