Light-driven radical copper-catalyzed allylic amination via allylic copper intermediates

The synthesis of allylic amines through an outer-sphere nucleophilic substitution mechanism involving electrophilic allyl copper(III) complexes with soft amines represents an uncharted territory in catalysis. This study introduces a radical-based approach for the generation of allylic copper(III) complexes, enabling the efficient synthesis of allylic amines in the presence of alkyl/aryl amines. Through copper photocatalysis, we demonstrate a radical-induced small-ring opening process that produces allylic amines featuring skipped double bonds, while simultaneously achieving highly regioselective 1,4-carboamination of 1,3-dienes with high E/Z selectivity. Mechanism studies substantiate the radical-mediated formation of allylic copper complexes and provide evidence for the involvement of outer-sphere nucleophilic substitution at allylic copper(III) complexes.