Catalytically Relevant Organocopper(III) Complexes Formed through Aryl-Radical-Enabled Oxidative Addition

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(22), С. 15176 - 15185

Опубликована: Май 21, 2024

Stepwise oxidative addition of copper(I) complexes to form copper(III) species via single electron transfer (SET) events has been widely proposed in copper catalysis. However, direct observation and detailed investigation these fundamental steps remain elusive owing largely the typically slow rate instability species. We report herein a novel aryl-radical-enabled stepwise pathway that allows for formation well-defined alkyl–CuIII from CuI complexes. The process is enabled by SET an aryl diazonium salt CuII radical. Subsequent iodine abstraction alkyl iodide radical affords radical, which then reacts with complex. structure resultant [(bpy)CuIII(CF3)2(alkyl)] characterized NMR spectroscopy X-ray crystallography. Competition experiments have revealed at different iodides undergo consistent carbon-centered radicals. intermediate formed during identified as four-coordinate complex, [CuII(CH3CN)2(CF3)2], through electronic paramagnetic resonance (EPR) studies. catalytic relevance high-valent organo-CuIII demonstrated C–C bond-forming reductive elimination reactivity. Finally, localized orbital bonding analysis formal CuIII indicates inverted ligand fields σ(Cu–CH2) bonds. These results demonstrate catalysis provide general strategy investigate

Язык: Английский

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On the Existence and Relevance of Copper(III) Fluorides in Oxidative Trifluoromethylation

Synlett, Год журнала: 2024, Номер unknown

Опубликована: Июнь 24, 2024

Abstract Numerous reports invoke CuIII–F intermediates engaging in oxidative cross-couplings mediated by low/mid-valent copper and formal sources of ‘F+’ oxidants. These elusive typically instable CuIII fluorides have been rarely characterized or spectroscopically identified, making their existence participation within catalytic cycles somehow questionable. We authenticated a stable organocopper(III) fluoride that undergoes Csp–CF3 bond formation upon addition silyl-capped alkynes following 2 e– CuIII/CuI redox shuttle. This finding strongly supports the intermediacy C–C coupling. review herein state art about well-defined enabling cross-coupling reactions. 1 Introduction Brief History Coupling-Competent Fluorides 3 Design an Isolable – yet Reactive Organocopper(III) Fluoride 4 Alkyne Trifluoromethylation: Scope Mechanism 5 Extension to Aryl–CF3 C–Heteroatom Couplings 6 Summary Outlook

Язык: Английский

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Well‐Defined Highly‐Coordinated Copper(III) Iodide and Pincer Tris(trifluoromethyl)copper Complexes

Chemistry - A European Journal, Год журнала: 2024, Номер unknown

Опубликована: Июль 8, 2024

Copper(III) iodide and bromide complexes representing a unique combination of highly-coordinated metal soft polarizable anions were synthesized fully characterized, including X-ray crystallography. Ligand substitution in well-defined copper complex PyCu(CF

Язык: Английский

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