Electrochemical Oxidation of Polyfluoroalkyl Iodides: Direct Anodic Transformation of C₈F₁₇CH₂CH₂I to Amides, Esters, and Etherst

The cyclic voltammetry of polyfluoroalkyl iodides of the type R_fCH₂CH₂I (R_f = n-C₆F₁₃, n-C₈F₁₇, n-C₁₀F₂₁) and R_fI (R_f = n-C₄F₉, n-C₆F₁₃, n-C₈F₁₇, n-C₁₀F₂₁) was investigated in nonaqueous media. All the iodides exhibited one distinctive oxidation peak, but only C₈F₁₇CH₂CH₂I was suitable for surveying preparative-scale electrosynthetic reactions because the other iodides either had poor solubility or caused severe filming of the anode. The direct anodic transformations of the iodide to the corresponding amides (C₈F₁₇CH₂CH₂NHCOR; R = CH₃, CH=CH₂, C(Me)=CH₂), esters (C₈F₁₇CH₂CH₂OCOR; R = CH₃, CF₃, CH=CH₂, C(Me)=CH₂, C₆H₅), ethers (mainly C₈F₁₇CH₂CH₂OCH₂CF₃), and alcohol (C₈F₁₇CH₂CH₂OH) were observed and a general mechanistic scheme involving a hypervalent iodanyl radical intermediate is proposed.