A Comprehensive Review of Radical-Mediated Intramolecular Cyano-Group Migration

Area of Science:

• Organic Chemistry
• Radical Chemistry
• Synthetic Methodology

Background:

• Radical-mediated intramolecular translocation of cyano groups enables site-selective functionalization of organic molecules.
• This process involves carbon-centered radical addition to nitrile triple bonds, followed by β-scission of iminyl radicals.
• Research has surged in recent decades due to advances in radical chemistry and photocatalysis.

Purpose of the Study:

• To provide a comprehensive review of radical-mediated cyano group translocation.
• To cover literature from 1961 to 2025.
• To categorize and discuss methods based on initial carbon radical generation strategies.

Main Methods:

• Literature review of studies on radical-mediated cyano group translocation.
• Categorization of methods into four sections based on radical generation: hydrogen-atom transfer (HAT), radical addition to π systems, halogen-atom transfer (XAT), and C-C single bond homolytic fission.
• Detailed discussion of reaction conditions, substrate scopes, and mechanisms for each method.

Main Results:

• The review consolidates diverse strategies for cyano group translocation.
• It highlights the evolution and advancements in the field over six decades.
• Key methods are systematically presented with emphasis on their scope and mechanistic pathways.

Conclusions:

• Radical-mediated cyano group translocation is a versatile synthetic tool.
• The review provides a valuable resource for researchers in organic synthesis and methodology development.
• Future research can build upon the discussed strategies for novel applications.