Stereoselective migratory heteroaryltrifluoromethylation of allylic amines via electrosynthesis

Abstract

An electrochemically initiated heteroaryltrifluoromethylation of allylic amines was developed. The cascade reaction involved the anodic oxidation of Langlois reagent (CF₃SO₂Na) to generate CF₃ radicals, followed by radical addition to the inactivated alkene, Smiles-type heteroaryl migration, and the reduction of nitrogen radicals. Unlike the conventional oxidative reaction mode, the SO₂ molecules from the Langlois reagent and Smiles rearrangement probably served as chemical reductants in the reaction cascade, giving a redox-neutral electrosynthesis. The reaction exhibited excellent regioselectivity and stereoselectivity. It provides an efficient method for the synthesis of enantiomerically pure β-heteroaryl-γ-trifluoromethyl amines and the stereoselective late-stage modification of biologically active compounds.