Researchers of the Zelinsky Institute have proposed new reagents for intercepting alkyl radicals

The active development of photoredox catalysis in recent years has made it possible to generate free radical species under much milder conditions compared to traditional chemical methods. With the use of photocatalytic transformations, previously impossible chemical processes were carried out. In addition, they are also distinguished by good compatibility with many functional groups. At present, the search for new types of reagents for use in photoredox-catalyzed free radical reactions with the aim of synthesizing previously hard-to-reach polyfunctional compounds is being actively pursued.

Scientists from the Laboratory of Functional Organic Compounds of the Zelinsky Institute proposed new reagents for intercepting alkyl radicals generated under photoredox catalysis — five-membered difluoroboryl chelate complexes based on azomethines. Azomethines themselves have some limitations in their participation in radical reactions associated with a reduced reactivity of the C=N bond or with special conditions for the formation of radical species. The conversion of azomethines into the corresponding difluoroboron chelate complexes makes it possible to successfully intercept alkyl radicals formed upon irradiation with light from a wide variety of precursors: alkyl trifluoroborates and alkyl siliconates, Hantzsch esters, anthranilamide aminals, N-hydroxyphthalimide esters, Katritzky salts, alkyl iodides, and thiols. The developed approach opens the way to the synthesis of a wide range of polyfunctional nitrogen-containing compounds.

Source:

Zakhar M. Rubanov, Vyacheslav I. Supranovich, Vitalij V. Levin, Alexander D. Dilman BF2-Chelates of N-Acylhydrazones as Versatile Coupling Partners in Photoredox Promoted Reactions // Eur. J. Org. Chem., 2023, 26, e202300247. DOI: 10.1002/ejoc.202300247.