Electrochemical Stereoselective Cyclopropanation and Ring Opening: a Route to Novel Cysteine Derivatives

A novel strategy for the stereoselective synthesis of cysteine derivatives containing a malonate fragment in the β-position has been proposed, based on a series of consecutive transformations in the Ni(II) Schiff-base coordination environment. Electrochemical Corey–Chaykovsky cyclopropanation of the dehydroalanine complexes followed by reductive ring opening and subsequent Michael addition of S-nucleophiles to thus formed unsaturated amino acids derivatives open a route to novel cysteine derivatives. New protocol for isolation of the substituted aryl cysteines with strong CH acidity via disassembling of the Schiff-base template has been elaborated.