Material-Efficient Microfluidic Platform for Exploratory Studies of Visible-Light Photoredox Catalysis

Area of Science:

• Photoredox Catalysis
• Flow Chemistry
• Microfluidics

Background:

• Visible-light photoredox catalysis is a powerful synthetic tool.
• Flow chemistry offers advantages in mixing and heat transfer.
• Microfluidic platforms enable precise control over reaction parameters.

Purpose of the Study:

• To present an automated microfluidic platform for in-flow studies of visible-light photoredox catalysis.
• To enable flexible control over residence time and photon flux.
• To demonstrate the platform's capability for direct translation from droplet screening to continuous synthesis.

Main Methods:

• An automated microfluidic platform was developed for liquid or gas-liquid reactions at the 15 μL scale.
• An oscillatory flow strategy was employed to control residence time.
• Actinometry was used to characterize the adjustable photon flux.

Main Results:

• The platform demonstrated efficient mixing and heat transfer.
• Case studies of oxidative hydroxylation and thiophenol dimerization showcased the system's capabilities.
• Reaction conditions optimized via droplet screening were successfully translated to continuous flow.

Conclusions:

• The automated microfluidic platform provides a versatile tool for visible-light photoredox catalysis.
• The oscillatory flow strategy ensures efficient reactions and preserves flow chemistry advantages.
• The system facilitates streamlined optimization and scale-up of catalytic processes.