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

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(33), С. 23555 - 23565

Опубликована: Авг. 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.

Язык: Английский

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Enantioconvergent copper-catalysed difluoromethylation of alkyl halides

Nature Catalysis, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 25, 2024

Язык: Английский

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New reactivity of late 3d transition metal complexes in catalytic reactions of alkynes

Chemical Society Reviews, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

This review summarizes seven types of new reactivities found in late 3d metal complexes and catalytic examples recent years.

Язык: Английский

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Key intermediates in CuI to CuIII catalytic cycle for ethoxycarbonyl difluoro-methylation

Chinese Chemical Letters, Год журнала: 2025, Номер unknown, С. 111051 - 111051

Опубликована: Март 1, 2025

Язык: Английский

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Overcoming Copper Reduction Limitation in Asymmetric Substitution: Aryl-Radical-Enabled Enantioconvergent Cyanation of Alkyl Iodides

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(46), С. 31982 - 31991

Опубликована: Ноя. 6, 2024

Cu-catalyzed enantioconvergent cross-coupling of alkyl halides has emerged as a powerful strategy for synthesizing enantioenriched molecules. However, this approach is intrinsically limited by the weak reducing power copper(I) species, which restricts scope compatible nucleophiles and necessitates extensive ligand optimization or use complex chiral scaffolds. To overcome these challenges, we introduce an aryl-radical-enabled that decouples halide activation step from Cu center. We demonstrate merging iodine abstraction with asymmetric radical functionalization enables conversion racemic α-iodoamides to nitrile products good yield enantioselectivity. The rational design ligands identified new class carboxamide-containing BOX ligands. Mechanistic studies support pathway unique hydrogen-bonding ability in newly designed This substitution reaction potential significantly expand reactions.

Язык: Английский

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Copper-Photoredox-Catalyzed Divergent Strategy for the Site-Selective Arylation and Alkylation of Glycines and Peptides

ACS Catalysis, Год журнала: 2024, Номер 14(24), С. 18896 - 18906

Опубликована: Дек. 12, 2024

There is a scarcity of general strategies for the site-selective α–Csp3–H arylation glycine derivatives to synthesize nonproteinogenic α-arylglycines that occur frequently in commercial drugs and bioactive molecules. We disclose copper-photoredox-catalyzed using diaryliodonium reagents (DAIRs) as arylating agents. This strategy harnesses underexplored ability DAIRs serve agents under visible-light irradiation copper salts photocatalysts. The method applies glycine-selective C–H peptides with electronically structurally diverse DAIRs. Moreover, we demonstrate photoinduced copper-catalyzed single electron transfer (SET) can be coupled halogen atom (XAT) process presence alkyl iodides accomplish alkylation glycines peptides. In this synergistic SET/XAT approach, phenyl radicals generated from diphenyl iodonium triflate mediate XAT generate iodides. Both these methods operate mild conditions exhibit broad scope appreciable functional group tolerance. Overall, divergent toolbox presented here facilitate access various alkylated arylated enable bioconjugation between drug

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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Enantioconvergent Copper-Catalysed Difluoromethylation of Alkyl Halides

Research Square (Research Square), Год журнала: 2024, Номер unknown

Опубликована: Авг. 16, 2024

Stereochemical-controlled hydrogen bond donors play essential roles in the pharmaceutical industry. Consequently, organic molecules that bear difluoromethyl (CF2H) groups at chiral centers are emerging as pivotal components pharmaceuticals due to their distinct hydrogenbonding property. However, a general approach for introducing CF2H an enantioselective manner remained elusive. Here, we show enantioconvergent difluoromethylation of racemic alkyl electrophiles, through radical intermediates, represents new strategy constructing CF2H-containing stereocenters. This is enabled by using copper catalysts bound with diamine ligand bearing electron-deficient phenyl groups, and nucleophilic difluoromethyl-zinc reagent. method allows high-yield conversion diverse range halides into alkyl-CF2H analogs excellent enantioselectivity (up 99% e.e.). Mechanistic studies, supported DFT calculations, revealed route involving asymmetric radicals crucial non-covalent interactions enantio-determining steps.

Язык: Английский

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Synthesis of Unsymmetrical 3,3′-Dialkyloxindole Boronic Esters from 3-Alkylidene-2-oxindoles Enabled by Copper Catalysis

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(14), С. 10403 - 10408

Опубликована: Июль 6, 2024

We describe a 1,2-alkylboration of 3-alkylidene-2-oxindoles with diboron reagent and alkyl bromides iodides enabled by copper/bisphosphine catalysis. This scalable alkylboration method provides facile access to 3,3'-dialkyloxindole boronic esters featuring an all-carbon quaternary stereocenter increased F(sp

Язык: Английский

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