Visible-light-driven cascade cyclization: a modular approach to functionalized 4-pyrrolin-2-ones.

Area of Science:

• Organic Chemistry
• Photocatalysis
• Synthetic Methodology

Background:

• 4-pyrrolin-2-ones are important heterocyclic scaffolds.
• Efficient synthesis of functionalized 4-pyrrolin-2-ones is crucial for drug discovery and materials science.
• Existing synthetic methods may lack efficiency, scope, or functional group tolerance.

Purpose of the Study:

• To develop an efficient and modular strategy for synthesizing densely functionalized 4-pyrrolin-2-ones.
• To explore a visible-light-driven Ru(II) photocatalysis approach.
• To enable diversity-oriented synthesis of valuable heterocyclic compounds.

Main Methods:

• Visible-light-driven Ru(II) photocatalysis.
• Radical cascade cyclization using diaryliodonium salts (DAIRs) and N-(acyloxy)phthalimides (NHPI esters) as radical precursors.
• Expansion of the methodology to include trifluoromethyl and arylsulfonyl radicals.

Main Results:

• Efficient construction of benzylated and alkylated 4-pyrrolin-2-one scaffolds.
• Successful incorporation of trifluoromethyl and arylsulfonyl groups.
• Demonstration of a broad substrate scope and high functional group tolerance.
• Scalability of the developed protocol.

Conclusions:

• The reported strategy provides a robust and versatile method for synthesizing diverse 4-pyrrolin-2-ones.
• Visible-light photocatalysis offers an attractive alternative for constructing complex heterocyclic structures.
• The methodology holds significant synthetic utility for accessing valuable chemical entities.