Pd-PEPPSI Complex Integrated into Hyper-Crosslinked Polymer: A Highly Stable and Reusable Catalyst for Heterogeneous...

Area of Science:

• Heterogeneous catalysis
• Polymer chemistry
• Organometallic chemistry

Background:

• Catalyst deactivation via metal aggregation or leaching is a significant hurdle in heterogeneous catalysis.
• Developing stable and recyclable single-site catalysts is crucial for efficient chemical transformations.

Purpose of the Study:

• To develop a single-site heterogeneous catalyst by immobilizing a homogeneous Pd-PEPPSI complex into a hyper-crosslinked polymer (HCP).
• To evaluate the catalyst's efficiency, stability, and recyclability in C-C coupling reactions.

Main Methods:

• A one-step direct knitting strategy was employed to incorporate the Pd-PEPPSI complex into an HCP.
• The resulting HCP-Pd-PEPPSI-3 catalyst was tested in Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions.
• Catalyst performance was assessed based on yield, turnover frequency (TOF), and recyclability over multiple cycles.

Main Results:

• The HCP-Pd-PEPPSI-3 catalyst demonstrated high efficiency in Suzuki-Miyaura coupling (99% yield) and Mizoroki-Heck coupling (98% yield) at low palladium loading (0.10 mol%).
• The catalyst exhibited excellent recyclability, maintaining 90% yield after 10 cycles.
• The hierarchical pore structure of the HCP effectively reduced palladium leaching and aggregation.

Conclusions:

• The direct knitting strategy successfully created a stable, single-site heterogeneous palladium catalyst.
• HCP-Pd-PEPPSI-3 offers a versatile and sustainable solution for palladium-catalyzed cross-coupling reactions, overcoming common deactivation challenges.