Electrosynthesis of Protected Dehydroamino Acids

Abstract

A NaCl-mediated electrochemical oxidation of amino acid carbamates (R1 = Boc, Cbz) afforded α-methoxylated α-amino acids. Subsequent acid-catalyzed elimination delivered valuable dehydroamino acid derivatives. The simplicity of our setup using graphite-electrodes was showcased, producing N-Boc-ΔAla-OMe on a decagram scale.

Spiers Memorial Lecture: Old but new organic electrosynthesis: history and recent remarkable developments

“…Quite recently, halide ions have been shown to be a powerful mediator for the electrosynthesis of protected dehydroamino acids. 14 Different from halide ion mediators such as Cl − , Br − and I − , the “fluoride ion mediator” is not a redox catalyst, but it greatly enhances the anodic substitution of organosulfur and selenium compounds. For example, sulfides do not undergo anodic α-alkoxylation in general unless they have a strongly electron-withdrawing group (EWG), such as CN and CF 3 groups, at their α-position.…”