Radical Deoxyfunctionalisation Strategies

Abstract

Due to their abundance and readily available synthesis, alcohols provide ideal handles for the selective derivatisation of organic molecules. Radical chemistry offers versatile strategies for the conversion of Csp3–O bonds into a wide range of Csp3–C or Csp3–heteroatom bonds. In these reactions, alcohols are readily derivatised with an activator group which can undergo facile mesolysis to generate a primary, secondary, or tertiary open-shell species that can engage in further transformations. These strategies are particularly effective at overcoming steric limitations associated with nucleophilic substitution pathways. Despite their potential, the use of radical deoxyfunctionalisation reactions as a general strategy for the synthesis of useful and complex molecules remains underutilised. Herein, we highlight recent advancements in this exciting field using photocatalysis, transition metal catalysis or electrochemistry to initiate the radical processes.

Visible-light-driven photocatalyst-free deoxygenative alkylation of imines with alcohols

“…Although numerous methods have been developed to enable C(sp 3 )–O bond homolytic cleavage of alcohols under photoredox catalysis, most of these approaches are generally not amenable to generation of nonstabilized alkyl radicals from primary alcohols. 12 In addition, the use of oxidative excited photocatalysts 13 would be harmful to the compatibility of the easily oxidizable amine products. Thus, it is highly desirable to develop a general and efficient strategy for the construction of α-branched amines from a broad range of alcohols and imines under non-oxidative conditions.…”