Mechanisms of Nickel-Catalyzed Cross-Coupling Reactions

Trends in Chemistry, Год журнала: 2019, Номер 1(9), С. 830 - 844

Опубликована: Сен. 13, 2019

Язык: Английский

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Nickel-Catalyzed Dicarbofunctionalization of Alkenes

ACS Catalysis, Год журнала: 2020, Номер 10(15), С. 8542 - 8556

Опубликована: Июль 2, 2020

1,2-Dicarbofunctionalization of alkenes has emerged as an efficient synthetic strategy for preparing substituted molecules by coupling readily available with electrophiles and/or nucleophiles. Nickel complexes serve effective catalysts owing to their tendency undergo facile oxidative addition and slow β-hydride elimination, capability access both two-electron radical pathways. Two-component alkene functionalization reactions have achieved high chemo-, regio-, stereoselectivities tethering one the partners substrate. Three-component reactions, however, often incorporate directing groups control selectivity. Only a few examples directing-group-free difunctionalizations unactivated been reported. Therefore, great opportunities exist development three-component difunctionalization broad substrate scopes tunable stereoselectivities.

Язык: Английский

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HFIP in Organic Synthesis

Chemical Reviews, Год журнала: 2022, Номер 122(15), С. 12544 - 12747

Опубликована: Июль 17, 2022

1,1,1,3,3,3-Hexafluoroisopropanol (HFIP) is a polar, strongly hydrogen bond-donating solvent that has found numerous uses in organic synthesis due to its ability stabilize ionic species, transfer protons, and engage range of other intermolecular interactions. The use this exponentially increased the past decade become choice some areas, such as C–H functionalization chemistry. In review, following brief history HFIP an overview physical properties, literature examples reactions using or additive are presented, emphasizing effect each reaction.

Язык: Английский

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Synergistic Dual Transition Metal Catalysis

Chemical Reviews, Год журнала: 2020, Номер 120(24), С. 13382 - 13433

Опубликована: Ноя. 29, 2020

Synergistic catalysis, a type of plural catalysis which utilizes at least two different catalysts to enable reaction between separately activated substrates, has unlocked plethora previously unattainable transformations and novel chemical reactivity. Despite the appreciable utility synergistic specific examples involving transition metals have been limited, as ensuring judicious choice parameters prevent deactivation catalysts, undesirable monocatalytic event(s) leading side products, or premature termination other potentially troublesome outcomes present formidable challenge. Excluding those driven by photocatalytic mechanisms, this review will highlight reported reactions that make use simultaneous catalytic cycles metal catalysts.

Язык: Английский

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Catalytic hydrogen atom transfer to alkenes: a roadmap for metal hydrides and radicals

Chemical Science, Год журнала: 2020, Номер 11(46), С. 12401 - 12422

Опубликована: Янв. 1, 2020

Hydrogen atom transfer from metal hydrides to alkenes appears underlie widely used catalytic methods – the mechanistic implications are fascinating.

Язык: Английский

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Site-Selective Catalytic Deaminative Alkylation of Unactivated Olefins

Journal of the American Chemical Society, Год журнала: 2019, Номер 141(41), С. 16197 - 16201

Опубликована: Сен. 29, 2019

A catalytic deaminative alkylation of unactivated olefins is described. The protocol characterized by its mild conditions, wide scope, including the use ethylene as substrate, and exquisite site-selectivity pattern for both α-olefins internal olefins, thus unlocking a new platform to forge sp3-sp3 linkages, even in context late-stage functionalization.

Язык: Английский

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Electroreductive Carbofunctionalization of Alkenes with Alkyl Bromides via a Radical-Polar Crossover Mechanism

Journal of the American Chemical Society, Год журнала: 2020, Номер 142(49), С. 20661 - 20670

Опубликована: Ноя. 24, 2020

Electrochemistry grants direct access to reactive intermediates (radicals and ions) in a controlled fashion toward selective organic transformations. This feature has been demonstrated variety of alkene functionalization reactions, most which proceed via an anodic oxidation pathway. In this report, we further expand the scope electrochemistry reductive alkenes. particular, strategic choice reagents reaction conditions enabled radical-polar crossover pathway wherein two distinct electrophiles can be added across highly chemo- regioselective fashion. Specifically, used strategy intermolecular carboformylation, anti-Markovnikov hydroalkylation, carbocarboxylation alkenes—reactions with rare precedents literature—by means electroreductive generation alkyl radical carbanion intermediates. These reactions employ readily available starting materials (alkyl halides, alkenes, etc.) simple, transition-metal-free display broad substrate good tolerance functional groups. A uniform protocol achieve all three transformations by simply altering medium. development provides new avenue for constructing Csp3–Csp3 bonds.

Язык: Английский

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On the Nature of C(sp³)–C(sp²) Bond Formation in Nickel-Catalyzed Tertiary Radical Cross-Couplings: A Case Study of Ni/Photoredox Catalytic Cross-Coupling of Alkyl Radicals and Aryl Halides

Journal of the American Chemical Society, Год журнала: 2020, Номер 142(15), С. 7225 - 7234

Опубликована: Март 20, 2020

The merger of photoredox and nickel catalysis has enabled the construction quaternary centers. However, mechanism, role ligand, effect spin state for this transformation related Ni-catalyzed cross-couplings involving tertiary alkyl radicals in combination with bipyridine diketonate ligands remain unknown. Several mechanisms have been proposed, all invoking a key Ni(III) species prior to undergoing irreversible inner-sphere reductive elimination. In work, we used open-shell dispersion-corrected DFT calculations, quasi-classical dynamics experiments study detail mechanism carbon–carbon bond formation Ni bipyridine- diketonate-based catalytic systems. These calculations revealed that access high states (e.g., triplet tetrahedral Ni(II) species) is critical effective radical cross-coupling radicals. Further, these disparate C–C formation. Specifically, contrary neutral Ni-bipyridyl system, lead directly corresponding products via an outer-sphere elimination step from intermediates. Implications design new transformations are discussed.

Язык: Английский

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Nickel-catalyzed formation of quaternary carbon centers using tertiary alkyl electrophiles

Chemical Society Reviews, Год журнала: 2021, Номер 50(6), С. 4162 - 4184

Опубликована: Янв. 1, 2021

This review provides a comprehensive summary of recent advances in nickel-catalyzed reactions employing tertiary alkyl electrophiles for the construction quaternary carbon centers.

Язык: Английский

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Nickel-Catalyzed Enantioconvergent Reductive Hydroalkylation of Olefins with α-Heteroatom Phosphorus or Sulfur Alkyl Electrophiles

Journal of the American Chemical Society, Год журнала: 2019, Номер 142(1), С. 214 - 221

Опубликована: Дек. 15, 2019

Substantial advances in enantioconvergent C(sp3)–C(sp3) bond formation reactions have been made recent years through the use of transition-metal-catalyzed cross-coupling racemic secondary alkyl electrophiles with organometallic reagents. Herein, we report a general process for asymmetric construction alkyl–alkyl bonds adjacent to heteroatoms, namely, nickel-catalyzed reductive hydroalkylation olefins α-heteroatom phosphorus or sulfur electrophiles. Including readily available olefins, this reaction has considerable advantages, such as mild conditions, broad substrate scope, and good functional group compatibility, making it desirable alternative traditional electrophile–nucleophile reactions.

Язык: Английский

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