Merocyanine-based photoacids as recyclable catalysts in visible-light-driven transformations

Area of Science:

• Organic chemistry
• Photocatalysis
• Green chemistry

Background:

• Proton transfer is vital in biological processes and chemical synthesis.
• Developing efficient and recyclable catalysts is a key goal in sustainable chemistry.
• Visible light photocatalysis offers an environmentally friendly approach to chemical transformations.

Purpose of the Study:

• To investigate the catalytic activity of protic merocyanine-based photoswitches.
• To demonstrate visible light-driven proton transfer for organic reactions.
• To explore the use of near-infrared light for photo-promoted catalysis.

Main Methods:

• Synthesis of protic merocyanine photoswitches.
• Irradiation with blue, green, or near-infrared light.
• Application in Friedel-Crafts reactions.
• Analysis of catalyst recovery and recyclability.

Main Results:

• Merocyanine photoswitches function as efficient homogeneous Brønsted acid catalysts under visible light.
• Photo-promoted proton release facilitates Friedel-Crafts reactions.
• Catalysts are easily recovered and reused.
• Near-infrared light (975 nm) successfully drives the reaction due to high two-photon absorption cross-section.

Conclusions:

• Merocyanine photoswitches offer a novel platform for visible and near-infrared light-driven catalysis.
• This approach provides an efficient and recyclable method for Friedel-Crafts reactions.
• The use of light as an external stimulus enhances catalytic sustainability.