Nickel-Catalyzed Radical Heck-Type C(sp³)–C(sp²) Coupling Cascades Enabled by Bromoalkane-Directed 1,4-Aryl Shift: Access to Olefinated Arylalanines

Abstract

A bromoalkane-directed radical 1,4-aryl shift strategy for nickel-catalyzed reductive Heck-type C(sp³)-C(sp²) coupling cascades of α-amino-β-bromocarboxylic acid esters with α-trifluoromethyl alkenes for producing <i>gem</i>-difluorinated arylalanines is presented. The α-aminoalkyl radicals generated from neophyl-type aryl migration function as robust coupling partners to allow for further Giese-type addition with electron-deficient α-trifluoromethyl alkenes and vinyl sulfones, thereby realizing a new radical cascade for the simultaneous installation of an aromatic ring and olefin motif into amino acid backbones.