Amidative β-Scission of Alcohols Enabled by Dual Catalysis of Photoredox Proton-Coupled Electron Transfer and Inner-Sphere Ni-Nitrenoid Transfer.
Hyeyun KeumHarin RyooDongwook KimSukbok ChangPublished in: Journal of the American Chemical Society (2023)
The photoredox/Ni dual catalysis is an appealing strategy to enable unconventional C-heteroatom bond formation. While significant advances have been achieved using this system, intermolecular C(sp 3 )-N bond formation has been relatively underdeveloped due to the difficulty in C(sp 3 )-N reductive elimination. Herein, we present a new mechanistic approach that utilizes dioxazolones as the Ni(II)-nitrenoid precursor to capture carbon-centered radicals by merging proton-coupled electron transfer (PCET) with nickel catalysis, thus forming synthetically versatile N -alkyl amides using alcohols. Based on mechanistic investigations, the involvement of (κ 2 - N , O )Ni(II)-nitrenoid species was proposed to capture photoredox PCET-induced alkyl radicals, thereby playing a pivotal role to enable the C(sp 3 )-N bond formation.