High throughput photo-oxidations in a packed bed reactor system

Area of Science:

• Photochemistry
• Organic Synthesis
• Chemical Engineering

Background:

• Continuous-flow systems offer efficiency in photochemical transformations.
• Singlet oxygen photo-oxidations are crucial but often rely on homogeneous photocatalysts requiring purification.

Purpose of the Study:

• To develop a robust, immobilized photocatalyst system for singlet oxygen generation in flow.
• To demonstrate the versatility of this system for various organic reactions and complex synthesis.

Main Methods:

• Immobilization of rose bengal onto a packed-bed photoreactor.
• Application of the flow system for singlet oxygen ene reactions, [4+2] cycloadditions, and heteroatom oxidations.
• Strategic use of the developed method in synthesizing artemisinin.

Main Results:

• The immobilized rose bengal system provides efficient access to singlet oxygen without catalyst contamination.
• A broad scope of organic transformations was successfully performed.
• The method proved effective for the synthesis of the antimalarial artemisinin.

Conclusions:

• Immobilized rose bengal in a flow photoreactor is a versatile and efficient platform for singlet oxygen chemistry.
• This approach simplifies synthetic routes and avoids post-reaction purification.
• The system holds significant potential for the scalable synthesis of valuable compounds.