Heterogeneous metallaphotoredox catalysis in a continuous-flow packed-bed reactor.

Area of Science:

• Synthetic Chemistry
• Catalysis
• Flow Chemistry

Background:

• Metallaphotoredox catalysis offers mild conditions for cross-couplings without noble metals.
• Increasing use in drug discovery necessitates sustainable and scalable methods.
• Heterogeneous catalysts simplify separation and enable continuous processes.

Purpose of the Study:

• To develop a continuous-flow system for metallaphotoredox catalysis.
• To integrate photo- and nickel catalytic functions into a single heterogeneous material.
• To demonstrate a simplified approach for scaling up reactions.

Main Methods:

• A heterogeneous catalyst combining photo- and nickel functions was synthesized.
• The catalyst was immobilized in a packed-bed reactor for continuous flow.
• Metallaphotoredox cross-coupling of sulfinates with aryl halides was used as a model.
• C-O arylations using carboxylic acids as nucleophiles were also investigated.

Main Results:

• The packed-bed reactor enabled simultaneous reaction and catalyst separation.
• The system demonstrated high stability over seven days with minimal yield decrease (≈1% per day).
• The method proved effective for both sulfinate and carboxylic acid nucleophiles.

Conclusions:

• A stable and efficient continuous-flow metallaphotoredox catalysis system was established.
• The integrated heterogeneous catalyst simplifies scalability and sustainability in synthetic chemistry.
• This approach facilitates the application of metallaphotoredox catalysis in drug discovery.