Electrophotocatalytic Decoupled Radical Relay Enables Highly Efficient and Enantioselective Benzylic C–H Functionalization

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(47), С. 21674 - 21682

Опубликована: Ноя. 17, 2022

Asymmetric sp3 C–H functionalization has been demonstrated to substantially expedite target molecule synthesis, spanning from feedstocks upgradation late-stage modification of complex molecules. Herein, we report a highly efficient and sustainable method for enantioselective benzylic cyanation by merging electrophoto- copper catalysis. A novel catalytic system allows one independently regulate the hydrogen atom transfer step radical formation speciation Cu(II)/Cu(I) effectively capture transient intermediate, through tuning electronic property anthraquinone-type photocatalyst simply modulating applied current, respectively. Such decoupled relay catalysis enables unified approach diverse alkylarenes, many which are much less reactive or even unreactive using existing relying on coupled relay. Moreover, current protocol is also amenable bioactive molecules, including natural products drugs.

Язык: Английский

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An overview on copper in industrial chemistry: From ancient pigment to modern catalysis

Coordination Chemistry Reviews, Год журнала: 2025, Номер 529, С. 216438 - 216438

Опубликована: Янв. 17, 2025

Язык: Английский

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Copper‐Catalyzed Intermolecular Enantioselective Radical Oxidative C(sp³)−H/C(sp)−H Cross‐Coupling with Rationally Designed Oxazoline‐Derived N,N,P(O)‐Ligands

Angewandte Chemie International Edition, Год журнала: 2021, Номер 60(51), С. 26710 - 26717

Опубликована: Окт. 5, 2021

The intermolecular asymmetric radical oxidative C(sp3 )-C(sp) cross-coupling of )-H bonds with readily available terminal alkynes is a promising method to forge chiral because the high atom and step economy, but remains underexplored. Here, we report copper-catalyzed (hetero)benzylic (cyclic)allylic C-H that occurs excellent enantioselectivity. Critical success rational design oxazoline-derived N,N,P(O)-ligands not only tolerate strong conditions which are requisite for hydrogen abstraction (HAA) processes also induce challenging enantiocontrol. Direct access range synthetically useful benzylic 1,4-enynes, site-selectivity among similar bonds, facile synthesis enantioenriched medicinally relevant compounds make this approach very attractive.

Язык: Английский

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Aryl Radical Enabled, Copper-Catalyzed Sonogashira-Type Cross-Coupling of Alkynes with Alkyl Iodides

ACS Catalysis, Год журнала: 2023, Номер 13(4), С. 2761 - 2770

Опубликована: Фев. 8, 2023

Despite the success of Sonogashira coupling for synthesis arylalkynes and conjugated enynes, engagement unactivated alkyl halides in such reactions remains historically challenging. We report herein a strategy that merges Cu-catalyzed alkyne transfer with aryl radical activation carbon-halide bonds to enable general approach iodides terminal alkynes. This unprecedented Sonogashira-type cross-coupling reaction tolerates broad range functional groups has been applied late-stage densely functionalized pharmaceutical agents as well positron emission tomography tracers.

Язык: Английский

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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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Hydroalkylation of Alkynes: Functionalization of the Alkenyl Copper Intermediate through Single Electron Transfer Chemistry

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(21), С. 7903 - 7908

Опубликована: Май 18, 2021

We have developed a method for the stereoselective coupling of terminal alkynes and α-bromo carbonyls to generate functionalized E-alkenes. The is accomplished by merging closed-shell hydrocupration with open-shell single electron transfer (SET) chemistry resulting alkenyl copper intermediate. demonstrate that reaction compatible various functional groups can be performed in presence aryl bromides, alkyl chlorides, esters, nitriles, amides, wide range nitrogen-containing heterocyclic compounds. Mechanistic studies provide evidence SET oxidation intermediate an ester as key step enables cross coupling.

Язык: Английский

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Green carbon–carbon homocoupling of terminal alkynes by a silica supported Cu(ii)-hydrazone coordination compound

Dalton Transactions, Год журнала: 2022, Номер 52(2), С. 421 - 433

Опубликована: Ноя. 29, 2022

A Cu(II) complex, [Cu(HL)(NO3)(CH3OH)]·CH3OH (1), was obtained by the reaction of Cu(NO3)2·3H2O and H2L in methanol solvent (H2L is (E)-4-amino-N'-(2-hydroxy-3-methoxybenzylidene)benzohydrazide). compound 1 were characterized various spectroscopic analyses molecular structure determined single-crystal X-ray analysis. The results indicated product a mononuclear complex contains free NH2 functional group on ligand. used for preparation heterogeneous catalyst supporting it functionalized silica gel. (Si-Cu) prepared an amidification with resulting silica-supported TGA, FT-IR, EPR, DRS, EDS, XRD, SEM XPS analyses. Si-Cu employed carbon-carbon coupling effects amount temperature investigated catalytic coupling. one products reactions (C16H22O2, CP1) analysis, which proved formation C-C bond production di-acetylene homocoupling terminal alkyne. This system stable can be reused without significant change its activity.

Язык: Английский

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Copper-Catalyzed C(sp3)–H Methylation via Radical Relay

ACS Catalysis, Год журнала: 2022, Номер 12(19), С. 11854 - 11859

Опубликована: Сен. 15, 2022

The methyl moiety is a key functional group that can result in major improvements the potency and selectivity of pharmaceutical agents. We present radical relay C–H methylation methodology employs β-diketiminate copper catalyst capable methylating unactivated C(sp3)–H bonds. Taking advantage bench-stable DABAL-Me3, an amine-stabilized trimethylaluminum reagent, range substrates possessing both activated bonds proceeds with minimal amount overmethylation. Mechanistic studies supported by experiment computation suggest intermediacy copper(II) intermediate reactive toward loss as well capture radicals R• to form R–Me

Язык: Английский

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Catalytic C(sp)-H carboxylation with CO2

Coordination Chemistry Reviews, Год журнала: 2023, Номер 486, С. 215138 - 215138

Опубликована: Март 30, 2023

Язык: Английский

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Mechanistic Basis of the Cu(OAc)₂ Catalyzed Azide-Ynamine (3 + 2) Cycloaddition Reaction

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(19), С. 13558 - 13570

Опубликована: Май 7, 2024

The Cu-catalyzed azide–alkyne cycloaddition (CuAAC) reaction is used as a ligation tool throughout chemical and biological sciences. Despite the pervasiveness of CuAAC, there need to develop more efficient methods form 1,4-triazole ligated products with low loadings Cu. In this paper, we disclose mechanistic model for ynamine-azide (3 + 2) cycloadditions catalyzed by copper(II) acetate. Using multinuclear nuclear magnetic resonance spectroscopy, electron paramagnetic high-performance liquid chromatography analyses, dual catalytic cycle identified. First, formation diyne species via Glaser–Hay coupling terminal ynamine forms Cu(I) competent catalyze an cycloaddition. Second, benzimidazole unit structure has multiple roles: assisting C–H activation, Cu coordination, postreaction resting state complex after completion Finally, reactivation shown addition isotopically labeled azide substrates product. This work provides basis use mixed valency binuclear in conjunction Cu-coordinating alkynes afford superior reactivity CuAAC reactions. Additionally, these data show how kinetics can be modulated changes alkyne substrate, which then predictable effect on mechanism.

Язык: Английский

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