Radical Cyclization-Initiated Difunctionalization Reactions of Alkenes and Alkynes

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Radical Reactions

Background:

• Radical reactions are versatile tools for creating functionalized molecular scaffolds.
• Previous reviews covered 1,2-difunctionalizations, remote difunctionalizations (1,3- to 1,7-), and addition-cyclization reactions.
• This work focuses on a different strategic approach: radical cyclization followed by a subsequent functionalization.

Purpose of the Study:

• To present a comprehensive overview of radical cyclization followed by a second functionalization strategy.
• To highlight the diverse methods available for the second functionalization step.
• To showcase the utility of this combined approach in molecular synthesis.

Main Methods:

• Radical cyclization reactions to form cyclic intermediates.
• Subsequent functionalization of the cyclized products.
• Methods for the second functionalization include atom transfer reactions.
• Radical or transition metal-assisted coupling reactions.
• Reactions with neutral molecules, cationic, and anionic species.

Main Results:

• Demonstration of radical cyclization as a key step preceding further molecular elaboration.
• Successful application of various reaction types for the second functionalization.
• Expansion of the scope of radical reactions in complex molecule synthesis.

Conclusions:

• Radical cyclization followed by a second functionalization is a powerful strategy for molecular synthesis.
• The described methods offer diverse pathways to complex, functionalized molecules.
• This approach enhances the synthetic chemist's ability to construct intricate molecular architectures.