Recent advances in sulfonylation reactions using potassium/sodium metabisulfite

Area of Science:

• Organic Chemistry
• Sulfur Chemistry
• Radical Reactions

Background:

• Sulfonyl-containing compounds are crucial in pharmaceuticals and materials science.
• Traditional methods for sulfonyl group introduction can be harsh or inefficient.
• Potassium metabisulfite and sodium metabisulfite offer a convenient source of sulfur dioxide.

Purpose of the Study:

• To summarize recent advancements in sulfonylation reactions utilizing metabisulfite salts.
• To highlight the mechanisms, including radical processes and catalytic approaches.
• To review photoinduced methods for sulfur dioxide insertion.

Main Methods:

• Utilizing potassium metabisulfite (PMS) or sodium metabisulfite (SMS) as SO2 surrogates.
• Employing radical reaction pathways for sulfur dioxide insertion.
• Applying transition metal catalysis and photoredox catalysis under visible or UV light.

Main Results:

• Successful synthesis of diverse sulfonyl-containing compounds under mild reaction conditions.
• Demonstration of efficient sulfur dioxide insertion via radical intermediates.
• Integration of catalytic systems (transition metal and photoinduced) for enhanced reactivity.

Conclusions:

• Metabisulfite salts are effective and versatile reagents for introducing sulfur dioxide.
• Radical-based sulfonylation offers a powerful strategy for constructing sulfonyl moieties.
• Catalytic and photochemical approaches expand the scope and efficiency of these transformations.