Cu-Catalyzed Sequential Dehydrogenation-Conjugate Addition for β-Functionalization of Saturated Ketones: Scope and Mechanism

The first copper-catalyzed direct beta-functionalization of saturated ketones is reported. This protocol enables diverse ketones to couple with a wide range of nitrogen, oxygen and carbon nucleophiles in generally good yields under operationally simple conditions. The detailed mechanistic studies including kinetic studies, KIE measurements, identification of reaction intermediates, EPR and UV-visible experiments were conducted, which reveal that this reaction proceeds via a novel radical-based dehydrogenation to enone and subsequent conjugate addition sequence.