Metal-organic framework boosts heterogeneous electron donor-acceptor catalysis

Area of Science:

• Materials Science
• Catalysis
• Organic Chemistry

Background:

• Metal-Organic Frameworks (MOFs) are versatile porous materials for heterogeneous catalysis.
• Electron donor-acceptor (EDA) photoactivation is a key strategy in chemical synthesis.
• Developing efficient and stable heterogeneous catalysts for EDA reactions remains a challenge.

Purpose of the Study:

• To design and synthesize a novel MOF, Zr-PZDB, for heterogeneous EDA photoactivation.
• To investigate the catalytic performance of Zr-PZDB in C-H coupling and late-stage functionalization reactions.
• To elucidate the mechanism of MOF-enabled EDA photoactivation.

Main Methods:

• Synthesis of Zr-PZDB MOF using Zr6-clusters and 4,4'-(phenazine-5,10-diyl)dibenzoate (PZDB) linkers.
• Catalytic evaluation of Zr-PZDB in Minisci-type reactions and coupling of aryl sulfonium salts.
• Spectroscopic studies (e.g., UV-Vis, EPR) to analyze EDA interactions and reaction mechanisms.

Main Results:

• Zr-PZDB demonstrated superior catalytic activity in various C-H coupling reactions with N-heterocycles and diverse coupling partners.
• The MOF enabled efficient late-stage functionalization of bioactive molecules.
• Spectroscopic evidence confirmed EDA interactions and a photoinduced single electron transfer mechanism within the MOF.
• The crowded MOF environment protected active centers, enhancing catalytic stability.

Conclusions:

• Zr-PZDB serves as an effective heterogeneous donor catalyst for EDA photoactivation.
• This work presents the first example of MOF-enabled heterogeneous EDA photoactivation.
• The developed MOF offers a promising platform for sustainable and efficient organic synthesis.