Continuous flow Sonogashira C-C coupling using a heterogeneous palladium-copper dual reactor

Area of Science:

• Catalysis
• Green Chemistry
• Chemical Engineering

Background:

• Continuous flow chemistry offers advantages in reaction control and scalability.
• Heterogeneous catalysis is crucial for efficient and recyclable chemical transformations.
• Sonogashashira coupling is a vital carbon-carbon bond-forming reaction in organic synthesis.

Purpose of the Study:

• To develop a novel heterogeneous catalyst system for continuous flow Sonogashira coupling.
• To evaluate the catalytic performance using a palladium (Pd) coated reactor and copper (Cu) tubing.
• To demonstrate a green chemistry approach by effectively trapping leached metals.

Main Methods:

• A continuous flow system was designed with an in-line palladium-coated tubular reactor and copper tubing.
• Sonogashira C-C coupling reactions were performed to assess catalyst system performance.
• A metal scavenging resin was employed to capture leached palladium and copper post-reaction.

Main Results:

• The Sonogashira coupling reactions proceeded effectively within the copper reactor, facilitated by trace palladium leached from the palladium reactor.
• The heterogeneous catalyst system demonstrated high efficiency in facilitating the C-C coupling.
• Efficient trapping of leached palladium and copper was achieved using a metal scavenging resin.

Conclusions:

• A novel and effective heterogeneous catalyst system for continuous flow Sonogashira coupling has been developed.
• The system leverages leached palladium for catalysis, offering a unique approach to heterogeneous catalysis.
• The integration of metal scavenging ensures a green chemistry pathway, minimizing metal contamination.