Electrorearranged Difunctionalization of 4-Hydroxy-α-benzopyrones

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Electrochemistry

Background:

• 4-hydroxycoumarins are versatile precursors for synthesizing complex organic molecules.
• Previous methods for functionalizing 4-hydroxycoumarins, such as photochemical conversion, have limitations in terms of efficiency and scope.
• Developing novel, efficient synthetic routes is crucial for accessing biologically relevant compounds.

Purpose of the Study:

• To explore an electrosynthetic strategy for the difunctionalization of 4-hydroxycoumarins.
• To synthesize alkyl 2-hydroxy-3-oxo-2,3-dihydrobenzofuran-2-carboxylates.
• To establish a more efficient and straightforward alternative to existing synthetic protocols.

Main Methods:

• Electrosynthetic difunctionalization of 4-hydroxycoumarins.
• Utilizing singlet oxygen insertion from molecular oxygen.
• Employing ambient temperature conditions.

Main Results:

• Successfully accessed diversely substituted alkyl 2-hydroxy-3-oxo-2,3-dihydrobenzofuran-2-carboxylates.
• Achieved high yields and reduced reaction times compared to photochemical methods.
• Demonstrated broad substrate scope and functional group tolerability.
• Confirmed operational simplicity and scalability of the electrosynthetic protocol.

Conclusions:

• Electrosynthesis provides a highly efficient and straightforward protocol for synthesizing valuable benzofuran derivatives.
• The developed method surpasses previous photochemical approaches in key performance metrics.
• This strategy offers a scalable and versatile route for accessing biologically promising compounds.