Radical Alkynylthiolation with Visible-Light-Sensitive S-Alkynylthio Sulfonates

Area of Science:

• Organic Chemistry
• Photochemistry
• Synthetic Methodology

Background:

• Visible-light photocatalysis has emerged as a powerful tool in organic synthesis.
• Developing novel photocatalyst-free methods for radical generation is crucial for sustainable chemistry.
• Efficient C-S bond formation strategies are essential for constructing complex organic molecules.

Purpose of the Study:

• To develop a novel S-alkynylthio sulfonate for photocatalyst-free radical reactions.
• To demonstrate the utility of this new compound in radical addition and coupling reactions.
• To investigate the mechanism of photolysis and C-S bond formation.

Main Methods:

• Synthesis of novel S-alkynylthio sulfonates.
• Visible-light irradiation for radical generation.
• Radical addition to multiple bond systems.
• Radical coupling with diazonium salts.
• Experimental and theoretical mechanistic studies.

Main Results:

• A novel S-alkynylthio sulfonate activated by visible light was successfully developed.
• Photocatalyst-free radical addition and coupling reactions were achieved with broad substrate scope.
• High regioselectivity and excellent functional group tolerance were observed.
• The method proved effective for late-stage modification of drug molecules.
• Mechanistic studies provided insights into the photolysis and C-S bond formation pathways.

Conclusions:

• The developed S-alkynylthio sulfonate offers a versatile and efficient platform for photocatalyst-free radical chemistry.
• This strategy expands the toolkit for C-S bond formation and functionalization.
• The method's applicability in late-stage drug modification highlights its potential in medicinal chemistry.