Oxidative addition of an alkyl halide to form a stable Cu(III) product

Science, Journal Year: 2023, Volume and Issue: 381(6662), P. 1072 - 1079

Published: Sept. 7, 2023

The step that cleaves the carbon-halogen bond in copper-catalyzed cross-coupling reactions remains ill defined because of multiple redox manifolds available to copper and instability high-valent product formed. We report oxidative addition α-haloacetonitrile ionic neutral copper(I) complexes form previously elusive but here fully characterized copper(III) complexes. stability these stems from strong Cu−CF 3 high barrier for C( CF )−C( CH 2 CN ) bond-forming reductive elimination. mechanistic studies we performed suggest proceeds by means two different pathways: an S N 2-type substitution complex a halogen-atom transfer complex. observed pronounced ligand acceleration addition, which correlates with couplings azoles, amines, or alkynes alkyl electrophiles.

Language: Английский

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General (hetero)polyaryl amine synthesis via multicomponent cycloaromatization of amines

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: Jan. 2, 2025

Language: Английский

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A general N-alkylation platform via copper metallaphotoredox and silyl radical activation of alkyl halides

Chem, Journal Year: 2021, Volume and Issue: 7(7), P. 1827 - 1842

Published: June 16, 2021

Language: Английский

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CuMoO4 nanostructures: A novel bifunctional material for supercapacitor and sensor applications

Journal of Energy Storage, Journal Year: 2022, Volume and Issue: 52, P. 104784 - 104784

Published: May 12, 2022

Language: Английский

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

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(22), P. 15176 - 15185

Published: May 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

Language: Английский

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Well-defined organometallic Copper(III) complexes: Preparation, characterization and reactivity

Coordination Chemistry Reviews, Journal Year: 2021, Volume and Issue: 442, P. 213923 - 213923

Published: May 11, 2021

Language: Английский

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Homogeneous oxidative transformations mediated by copper catalyst systems

Coordination Chemistry Reviews, Journal Year: 2021, Volume and Issue: 440, P. 213958 - 213958

Published: April 21, 2021

Language: Английский

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Copper–Carbon Homolysis Competes with Reductive Elimination in Well-Defined Copper(III) Complexes

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(48), P. 26152 - 26159

Published: Nov. 22, 2023

Despite the recent advancements of Cu catalysis for cross-coupling alkyl electrophiles and frequently proposed involvement alkyl-Cu(III) complexes in such reactions, little is known about reactivity these high-valent complexes. Specifically, although reversible interconversion between an alkyl-CuIII complex radical/CuII pair has been catalysis, direct observation steps well-defined CuIII remains elusive. In this study, we report synthesis investigation complexes, which exclusively undergo a Cu-C homolysis pathway to generate radicals CuII species. Kinetic studies suggest bond dissociation energy 28.6 kcal/mol CuIII-C bonds. Moreover, four-coordinate could be converted solvated alkyl-CuIII-(CF3)2, undergoes highly efficient C-CF3 bond-forming reductive elimination even at low temperatures (-4 °C). These results provide strong support recombination with form species, elusive step that Cu-catalyzed mechanisms. Furthermore, our work demonstrated significantly influenced by subtle changes coordination environment. Lastly, reactive neutral alkyl-CuIII-(CF3)2 species (or weakly bound solvent molecules) suggests they might true intermediates many trifluoromethylation reactions.

Language: Английский

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Oxidative Substitution of Organocopper(II) by a Carbon-Centered Radical

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(33), P. 23555 - 23565

Published: Aug. 8, 2024

Copper-catalyzed coupling reactions of alkyl halides are believed to prominently involve copper(II) species and radicals as pivotal intermediates, with their exact interaction mechanism being the subject considerable debate. In this study, a visible light-responsive fluoroalkylcopper(III) complex, [(terpy)Cu(CF3)2(CH2CO2tBu)] Trans-1, was designed explore mechanism. Upon exposure blue LED irradiation, Trans-1 undergoes copper–carbon bond homolysis, generating Cu(II) carbon-centered radicals, where radical then recombines intermediate, resulting in formation Cis-1, Cis isomer Trans-1. Beyond this, well-defined fluoroalkylcopper(II) intermediate ligated sterically hindered ligand isolated underwent full characterization electronic structure studies. The collective experimental, computational, spectroscopic findings work strongly suggest that organocopper(II) engages via an "oxidative substitution" mechanism, which is likely operational pathway for copper-catalyzed C–H trifluoromethylation reactions.

Language: Английский

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Recent Advances in Theoretical Studies on Cu-Mediated Bond Formation Mechanisms Involving Radicals

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(4), P. 2429 - 2454

Published: Feb. 1, 2024

Copper-catalyzed radical transformations establish a powerful toolkit to construct versatile complex organic compounds. The copper-mediated bond formation step of radicals plays critical role in controlling chemo- and stereoselectivity copper-catalyzed transformation reactions. This involves three possible pathways: ion-type formation, substitution, reductive elimination. review highlights the recent advances theoretical studies on mechanisms models selectivity Cu-mediated radical-involved providing general mechanistic comprehension this key elementary copper catalysis.

Language: Английский

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