Elucidating electron-transfer events in polypyridine nickel complexes for reductive coupling reactions

Nature Catalysis, Год журнала: 2023, Номер 6(3), С. 244 - 253

Опубликована: Март 9, 2023

Язык: Английский

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Interrogating the Mechanistic Features of Ni(I)-Mediated Aryl Iodide Oxidative Addition Using Electroanalytical and Statistical Modeling Techniques

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(15), С. 8689 - 8699

Опубликована: Апрель 4, 2023

While the oxidative addition of Ni(I) to aryl iodides has been commonly proposed in catalytic methods, an in-depth mechanistic understanding this fundamental process is still lacking. Herein, we describe a detailed study using electroanalytical and statistical modeling techniques. Electroanalytical techniques allowed rapid measurement rates for diverse set iodide substrates four classes catalytically relevant complexes (Ni(MeBPy), Ni(MePhen), Ni(Terpy), Ni(BPP)). With >200 experimental rate measurements, were able identify essential electronic steric factors impacting through multivariate linear regression models. This led classification mechanisms, either three-center concerted or halogen-atom abstraction pathway based on ligand type. A global heat map predicted was created shown applicable better reaction outcome case Ni-catalyzed coupling reaction.

Язык: Английский

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Mechanistic Investigation of Ni-Catalyzed Reductive Cross-Coupling of Alkenyl and Benzyl Electrophiles

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(27), С. 14705 - 14715

Опубликована: Июнь 26, 2023

Mechanistic investigations of the Ni-catalyzed asymmetric reductive alkenylation

Язык: Английский

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Enantioselective C(sp²)–C(sp³) Bond Construction by Ni Catalysis

Accounts of Chemical Research, Год журнала: 2024, Номер 57(5), С. 751 - 762

Опубликована: Фев. 12, 2024

ConspectusAfter decades of palladium dominating the realm transition-metal-catalyzed cross-coupling, recent years have witnessed exciting advances in development new nickel-catalyzed cross-coupling reactions to form C(sp3) centers. Nickel possesses distinct properties compared with palladium, such as facile single-electron transfer electrophiles and rapid C–C reductive elimination from NiIII. These properties, among others, make nickel particularly well-suited for (RCC) which two are coupled an exogenous reductant is used turn over metal catalyst. Ni-catalyzed RCCs use readily available stable starting materials exhibit good functional group tolerance, makes them appealing applications synthesis complex molecules. Building upon foundational work by groups Kumada, Durandetti, Weix, well advancements enantioselective redox-neutral cross-couplings led Fu co-workers, we initiated a program explore feasibility developing highly RCCs. Our research has also been driven keen interest unraveling factors contributing enantioinduction electrophile activation seek avenues advancing our understanding further these reactions.In first part this Account, organize reported methods on basis identity electrophiles, including benzylic chlorides, N-hydroxyphthalimide (NHP) esters, α-chloro esters nitriles. We highlight how selection specific chiral ligands plays pivotal role achieving high cross-selectivity enantioselectivity. In addition, show that reduction can be accomplished not only heterogeneous reductants, Mn0, but soluble organic tetrakis(dimethylamino)ethylene (TDAE), electrochemically. The homogeneous TDAE, suited studying mechanism transformation. Although Account primarily focuses RCCs, using trifluoroborate (BF3K) salts radical precursors dual-Ni/photoredox systems.At end summarize relevant mechanistic studies closely related asymmetric alkenylation developed laboratory provide context between others. discuss ligand influence rates mechanisms mode generation optimize yield RCC. endeavors offer insights intricate at play goal rate improve substrate scope anticipate share guidance field.

Язык: Английский

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Enantioselective Reductive Cross-Couplings of Olefins by Merging Electrochemistry with Nickel Catalysis

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(44), С. 23910 - 23917

Опубликована: Окт. 26, 2023

The merger of electrochemistry and transition metal catalysis has emerged as a powerful tool to join two electrophiles in an enantioselective manner. However, the development electroreductive cross-couplings olefins remains challenge. Inspired by advantages synergistic use with nickel catalysis, we present here Ni-catalyzed cross-coupling acrylates aryl halides alkyl bromides, which affords chiral α-aryl carbonyls good excellent enantioselectivity. Additionally, this catalytic reaction can be applied (hetero)aryl chlorides, is difficult achieve other methods. combination cyclic voltammetry analysis electrode potential studies suggests that NiI species activates oxidative addition bromides single-electron transfer.

Язык: Английский

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Mechanisms of Photoredox Catalysis Featuring Nickel–Bipyridine Complexes

ACS Catalysis, Год журнала: 2024, Номер 14(11), С. 9055 - 9076

Опубликована: Май 29, 2024

Metallaphotoredox catalysis can unlock useful pathways for transforming organic reactants into desirable products, largely due to the conversion of photon energy chemical potential drive redox and bond transformation processes. Despite importance these processes cross-coupling reactions other transformations, their mechanistic details are only superficially understood. In this review, we have provided a detailed summary various photoredox mechanisms that been proposed date Ni-bipyridine (bpy) complexes, focusing separately on photosensitized direct excitation reaction By highlighting multiple key findings, depict how mechanisms, which ultimately define substrate scope, themselves defined by ground- excited-state geometric electronic structures Ni-based intermediates. We further identify knowledge gaps motivate future studies development synergistic research approaches spanning physical, organic, inorganic chemistry communities.

Язык: Английский

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Cross-Electrophile Coupling: Principles, Methods, and Applications in Synthesis

Chemical Reviews, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 26, 2024

Cross-electrophile coupling (XEC), defined by us as the cross-coupling of two different σ-electrophiles that is driven catalyst reduction, has seen rapid progression in recent years. As such, this review aims to summarize field from its beginnings up until mid-2023 and provide comprehensive coverage on synthetic methods current state mechanistic understanding. Chapters are split type bond formed, which include C(sp

Язык: Английский

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C–heteroatom coupling with electron-rich aryls enabled by nickel catalysis and light

Nature Catalysis, Год журнала: 2024, Номер 7(6), С. 733 - 741

Опубликована: Май 7, 2024

Abstract Nickel photoredox catalysis has resulted in a rich development of transition-metal-catalysed transformations for carbon–heteroatom bond formation. By harnessing light energy, the transition metal can attain oxidation states that are difficult to achieve through thermal chemistry catalytic manifold. For example, nickel reactions have been reported both synthesis anilines and aryl ethers from aryl(pseudo)halides. However, oxidative addition simple systems is often sluggish absence special, electron-rich ligands, leading catalyst decomposition. Electron-rich electrophiles therefore currently fall outside scope many field. Here we provide conceptual solution this problem demonstrate nickel-catalysed C–heteroatom bond-forming arylthianthrenium salts, including amination, oxygenation, sulfuration halogenation. Because redox properties salts primarily dictated by thianthrenium, highly donors be unlocked using NiCl 2 under irradiation form desired C‒heteroatom bonds.

Язык: Английский

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Mechanism of Ni-Catalyzed Photochemical Halogen Atom-Mediated C(sp³)–H Arylation

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(22), С. 15331 - 15344

Опубликована: Май 23, 2024

Within the context of Ni photoredox catalysis, halogen atom photoelimination from has emerged as a fruitful strategy for enabling hydrogen transfer (HAT)-mediated C(sp3)–H functionalization. Despite numerous synthetic transformations invoking this paradigm, unified mechanistic hypothesis that is consistent with experimental findings on catalytic systems and accounts radical formation facile C(sp2)–C(sp3) bond remains elusive. We employ kinetic analysis, organometallic synthesis, computational investigations to decipher mechanism prototypical Ni-catalyzed photochemical arylation reaction. Our revise previous proposals, first by examining relevance SET EnT processes intermediates relevant HAT-based investigation highlights ability blue light promote efficient Ni–C(sp2) homolysis cationic NiIII reductive elimination bipyridine NiII complexes. However interesting, rates selectivities these do not account productive pathway. Instead, our studies support involves evolution in situ generated dihalide intermediates, capture NiII(aryl)(halide) resting state, key C–C NiIII. Oxidative addition NiI, opposed Ni0, rapid NiIII/NiI comproportionation play roles process. The presented herein offer fundamental insight into reactivity broader catalysis.

Язык: Английский

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Paired electrolysis-enabled nickel-catalyzed enantioselective reductive cross-coupling between α-chloroesters and aryl bromides

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Ноя. 28, 2022

Electrochemical asymmetric catalysis has emerged as a sustainable and promising approach to the production of chiral compounds utilization both anode cathode working electrodes would provide unique for organic synthesis. However, precise matching rate electric potential anodic oxidation cathodic reduction make such idealized electrolysis difficult achieve. Herein, cross-coupling between α-chloroesters aryl bromides is probed model reaction, wherein alkyl radicals are generated from through sequential oxidative electron transfer process at anode, while nickel catalyst reduced lower state cathode. Radical clock studies, cyclic voltammetry analysis, paramagnetic resonance experiments support synergistic involvement redox events. This electrolytic method provides an alternative avenue that could find significant utility in

Язык: Английский

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