Tuning Reactivity in Cu/TEMPO Catalyzed Alcohol Oxidation Reactions DOI Creative Commons

Maximilian Schütze,

Matthias Jux,

Beatrice Cula

et al.

Chemistry - An Asian Journal, Journal Year: 2025, Volume and Issue: unknown

Published: April 30, 2025

A dinuclear copper(I) complex Cu2L22 (L2 = 3,3-dimethyl-1-(1-methyl-1H-benzo[d]imidazole-2-yl)-N-(propan-2-ylidene)butan-2-amine) containing benzimidazole and imino donors was previously reported by some of us as an efficient catalyst for the aerobic oxidation alcohols to aldehydes in presence TEMPO (2,2,6,6-tetramethylpiperidinyloxyl) external base NMI (N-methyl imidazole). Cu(III)2(bis-μ-oxo) Cu(II)2(bis-μ-hydroxo) cores were trapped viable intermediates reaction, which provided deeper mechanistic insights. Here, we report two new ligand systems L3 (N-isopropyl-3,3-dimethyl-1-(1-methyl-1H-benzol[d]imidazole-2-yl)butane-2-amine) L4 ((Z)-2,4-di-tert-butyl-6-(((3,3-dimethyl-1-(1-methyl-1H-benzol[d]imidazole-2-yl)butane-2-yl)imino)methyl)phenol), are designed perturb overall electronics complexes resulting effects on their O2 activation mechanisms. The stronger donation secondary amine group stabilizes a mononuclear CuIL3 core, nevertheless follows mechanism Cu2L22. Notably, CuIL3/TEMPO system performs with good yields turnover numbers, even absence NMI. CuI 2L42 involving non-innocent phenolate group, contrast, exhibits depleted catalytic activity, because instability core against intramolecular H-atom abstraction form alkoxo bridged dicopper(II) complex.

Language: Английский

Tuning Reactivity in Cu/TEMPO Catalyzed Alcohol Oxidation Reactions DOI Creative Commons

Maximilian Schütze,

Matthias Jux,

Beatrice Cula

et al.

Chemistry - An Asian Journal, Journal Year: 2025, Volume and Issue: unknown

Published: April 30, 2025

A dinuclear copper(I) complex Cu2L22 (L2 = 3,3-dimethyl-1-(1-methyl-1H-benzo[d]imidazole-2-yl)-N-(propan-2-ylidene)butan-2-amine) containing benzimidazole and imino donors was previously reported by some of us as an efficient catalyst for the aerobic oxidation alcohols to aldehydes in presence TEMPO (2,2,6,6-tetramethylpiperidinyloxyl) external base NMI (N-methyl imidazole). Cu(III)2(bis-μ-oxo) Cu(II)2(bis-μ-hydroxo) cores were trapped viable intermediates reaction, which provided deeper mechanistic insights. Here, we report two new ligand systems L3 (N-isopropyl-3,3-dimethyl-1-(1-methyl-1H-benzol[d]imidazole-2-yl)butane-2-amine) L4 ((Z)-2,4-di-tert-butyl-6-(((3,3-dimethyl-1-(1-methyl-1H-benzol[d]imidazole-2-yl)butane-2-yl)imino)methyl)phenol), are designed perturb overall electronics complexes resulting effects on their O2 activation mechanisms. The stronger donation secondary amine group stabilizes a mononuclear CuIL3 core, nevertheless follows mechanism Cu2L22. Notably, CuIL3/TEMPO system performs with good yields turnover numbers, even absence NMI. CuI 2L42 involving non-innocent phenolate group, contrast, exhibits depleted catalytic activity, because instability core against intramolecular H-atom abstraction form alkoxo bridged dicopper(II) complex.

Language: Английский

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