Modulating Electron Transfer via Cerium Photocatalysis for Alkoxy Radical-Mediated Selective Hydroetherification

Area of Science:

• Organic Chemistry
• Photocatalysis
• Catalysis

Background:

• Directly coupling alcohols with electron-rich alkenes is challenging due to polarity mismatches.
• Existing methods often lack selectivity or require harsh conditions.

Purpose of the Study:

• To develop a catalytic platform for direct coupling of free alcohols and electron-rich alkenes.
• To overcome selectivity issues in single-electron transfer processes.
• To establish a practical and atom-economical hydroetherification framework.

Main Methods:

• Utilizing cerium(IV) benzoate complexes as a photocatalyst.
• Employing ligand-to-metal charge transfer (LMCT) for radical generation.
• Investigating regioselective hydroetherification pathways (intramolecular cyclization and intermolecular addition).

Main Results:

• Selective generation of electrophilic alkoxy radicals from free alcohols.
• Successful hydroetherification of diverse alkenes, including silyl enol ethers, enamides, and enecarbamates.
• Demonstrated broad functional group tolerance and operational simplicity.

Conclusions:

• The Ce-benzoate system provides a unique selectivity for alkoxy radical generation.
• This photocatalytic protocol offers a versatile and efficient method for hydroetherification.
• The study establishes a practical and atom-economical approach for C-O bond formation.