Open-Shell Species Enabled Diverse Deoxygenative Cyanofunctionalization of Aldehydes under Metal-Free Conditions.

The conversion of carbonyl compounds to functionalized nitriles enables both one-carbon homologation and rapid multifunctionalization, especially considering the diverse transformation potential of the cyano group. Herein, by simultaneously introducing a cyano and a suitable C-O activated group into carbonyl compounds, we successfully achieved an efficient deoxygenative cyanofunctionalization of unactivated aliphatic aldehydes via a free radical process. Due to the unique characteristics of the open-shell species, this protocol can readily facilitate a variety of bond formations to install alkyl ketone, alkenyl, allylic, halo, phosphorus, and sulfur groups. Additionally, a direct deoxygenative cyanation with excellent scope and functional group compatibility was demonstrated under mild conditions. The fact that there is no need for toxic cyanide salts or metal catalysts further enhances the practicality of this simple, modular method to access diverse nitrile compounds, providing an elegant strategy for the late-stage modification of complex molecules.