Photoinduced EDA-Complex-Mediated Radical Cascade toward Sulfonylated Quinoline-2,4-Diones

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Medicinal Chemistry

Background:

• Quinoline-2,4(1H,3H)-diones are important heterocyclic scaffolds.
• Efficient synthesis of sulfonylated derivatives is challenging.

Purpose of the Study:

• To develop a novel synthetic route to sulfonylated quinoline-2,4(1H,3H)-diones.
• To explore the mechanism of electron donor-acceptor (EDA) complex-mediated reactions.

Main Methods:

• Utilized electron donor-acceptor (EDA) complexation between triethylamine (Et3N) and thiosulfonates.
• Performed oxidative radical addition/cyclization reactions with o-cyanoarylacrylamides.

Main Results:

• Successfully synthesized sulfonylated quinoline-2,4(1H,3H)-diones.
• Elucidated the reaction mechanism involving R-SO2 radical intermediates.
• Demonstrated the formation of the quinoline-2,4(1H,3H)-dione core through cyclization and hydrolysis.

Conclusions:

• The developed EDA complex-mediated strategy provides direct access to sulfonylated quinoline-2,4(1H,3H)-diones.
• The reaction mechanism involves radical generation and addition followed by cyclization and functional group transformations.