Aryl radical generation through hydrohalic bond scission initiated by N-heterocyclic carbene catalysts
In a groundbreaking discovery, researchers at Kanazawa University and led by Professor Frank Glorius have developed a chemical reaction that efficiently generates aryl radicals from aryl iodides under mild conditions. This research, published in the prestigious journal "Science," promises to be a game-changer in the field of organic synthesis.
Aryl radicals, generated through this reaction, can serve as a valuable source of benzene rings in organic synthesis. They can be utilised for the difunctionalization of alkene, resulting in benzene-ring substituted ketone. Moreover, these radicals act as a source of the benzene ring itself, making them indispensable for a wide range of organic syntheses.
The significance of this research lies in the fact that the reaction employs an N-heterocyclic carbene catalyst, which boasts a low environmental impact. Previously, chemical reactions to generate aryl radicals from aryl halides required either metal catalysts or photocatalysts, which raised concerns about their environmental footprint.
The process involves a single electron transfer from an enolate intermediate to an aryl iodide, followed by the cleavage of the bond between the benzene ring and the iodine atom, thereby generating an aryl radical in a catalytic manner.
The aryl radical, thus generated, can undergo intramolecular hydrogen abstraction reaction, facilitating the dehydrogenative acylation of amide. This reaction leads to the formation of α-aminoketone compounds, a class of compounds that are essential in the synthesis of various medical and agricultural drugs, as well as chemical materials.
This innovative technology is expected to be a powerful tool for precisely synthesizing a wide range of complex organic compounds, opening up new possibilities in the pharmaceutical and chemical industries.
