Copper-catalyzed [1,3]-nitrogen rearrangement of O-aryl ketoximes via oxidative addition of N-O bond in inverse electron flow

• Published in: Chemical science (Cambridge) Vol. 14; no. 21; pp. 5705 - 5711
• Main Authors: Suzuki, Mao, Terada, Masahiro, Nakamura, Itaru
• Format: Journal Article
• Language: English
• Published: CAMBRIDGE Royal Soc Chemistry 31.05.2023; Royal Society of Chemistry; The Royal Society of Chemistry
• Subjects: Aminophenol; Aromatic compounds; Catalysts; Chemistry; Chemistry, Multidisciplinary; Copper; Density functional theory; Electrons; Nitrogen atoms; Physical Sciences; Science & Technology; Substrates; MIGRATION; AMINATION; OXIMES; MECHANISM; AMIDATION; TRIFLUOROMETHOXYLATION; DERIVATIVES; C-H BONDS; (HETERO)ARENES; MOLECULES
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d3sc00874f

The [1,3]-nitrogen rearrangement reactions of O-aryl ketoximes were promoted by N-heterocyclic carbene (NHC)-copper catalysts and BF3 center dot OEt2 as an additive, affording ortho-aminophenol derivatives in good yields. The reaction of substrates with electron-withdrawing substituents on the phenol moiety are accelerated by adding silver salt and modifying the substituent at the nitrogen atom. Density functional theory calculations suggest that the rate-determining step of this reaction is the oxidative addition of the N-O bond of the substrate to the copper catalyst. The negative rho values of the substituent at both the oxime carbon and phenoxy group indicate that the donation of electrons by the oxygen and nitrogen atoms accelerates the oxidative addition.