With the participation of ZIOC RAS, a new approach to the activation of organic compounds is being developed

Chemical functional groups have their own reactivity, arising from a unique individual combination of electronic and structural features. A change in the reactivity of a functional group opens up new ways of using it in chemical transformations. Most often, additional reagents are used for this purpose, such as acids/bases or hydrogen bond donors/acceptors. A fundamentally different approach is based on a conformational change in a molecule with a functional group. Rotation around a single chemical bond can lead to significant changes in reactivity. This approach is atom-economical and opens up new possibilities in the design of catalytic processes.

An international team of scientists from the Zelinsky Institute, Arbuzov Institute, and Florida State University (USA) discovered new facets of the reactivity of substituted ureas. The implementation of such processes became possible due to rotation around one of the C-N bonds of urea, which turns off the amide resonance and increases the nucleophilicity of one of the nitrogen atoms. An important role in this case is played by the nature of urea substitution: the most substituted ureas are more flexible, since the loss of resonance in such systems is accompanied by the removal of steric stress. The use of such a "conformational adjustment" made it possible to synthesize unusual 2-oxoimidazolium salts containing quaternary nitrogen atoms in the urea residue. It is expected that this approach will not be limited to ureas and will find further application in organic synthesis.
 

Source:

Almir S. Gazizov, Andrey V. Smolobochkin, Tanzilya S. Rizbayeva, Sergey Z. Vatsadze, Alexander R. Burilov, Oleg G. Sinyashin, Igor V. Alabugin “Stereoelectronic Deprotection of Nitrogen”: Recovering Nucleophilicity with a Conformational Change // J. Org. Chem. 2023, 88, 6868−6877. DOI: 10.1021/acs.joc.3c00161.