Radical ligand transfer: a general strategy for radical functionalization.

Area of Science:

• Organic Chemistry
• Catalysis
• Free Radical Chemistry

Background:

• Alkyl radicals have evolved from difficult-to-control species to versatile intermediates in organic synthesis.
• Advances in radical generation (e.g., hydrogen atom transfer, decarboxylation) and functionalization (e.g., radical-polar crossover) have been crucial.
• Directly engaging alkyl radicals in bond-forming reactions remains a challenge.

Purpose of the Study:

• To provide an overview of the evolution of radical ligand transfer (RLT) catalysis.
• To highlight the key features and advantages of RLT catalysis.
• To offer a conceptual framework for future research in RLT.

Main Methods:

• Overview of radical generation methods (HAT, alkene addition, decarboxylation).
• Discussion of radical functionalization strategies, including radical-polar crossover (RPC).
• Focus on the mechanistic paradigm of radical ligand transfer (RLT) catalysis.

Main Results:

• RLT catalysis enables the formation of diverse bonds (C-X, C-N, C-S) catalytically to alkyl radicals.
• RLT utilizes simple, earth-abundant element catalysts.
• RLT is compatible with various radical generation methods.

Conclusions:

• Radical ligand transfer (RLT) catalysis is a promising and versatile approach for engaging alkyl radicals.
• The bio-inspired RLT mechanism offers significant advantages for catalytic bond formation.
• This review aims to inspire future advancements in RLT catalysis.