Enantioselective C(sp³)–C(sp³) Reductive Cross-Electrophile Coupling of Unactivated Alkyl Halides with α-Chloroboronates via Dual Nickel/Photoredox Catalysis

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(4), P. 2081 - 2087

Published: Jan. 23, 2023

Substantial advances in enantioconvergent C(sp3)-C(sp3) bond formations have been made with nickel-catalyzed cross-coupling of racemic alkyl electrophiles organometallic reagents or nickel-hydride-catalyzed hydrocarbonation alkenes. Herein, we report an unprecedented enantioselective reductive by the direct utilization two different halides dual nickel/photoredox catalysis system. This highly selective coupling α-chloroboronates and unactivated iodides furnishes chiral secondary boronic esters, which serve as useful important intermediates realm organic synthesis enable a desirable protocol to fast construction enantioenriched complex molecules.

Language: Английский

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Native Amides as Enabling Vehicles for Forging sp³–sp³ Architectures via Interrupted Deaminative Ni-Catalyzed Chain-Walking

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(7), P. 3869 - 3874

Published: Feb. 8, 2023

Herein, we disclose an interrupted deaminative Ni-catalyzed chain-walking strategy that forges sp3-sp3 architectures at remote, yet previously unfunctionalized, methylene sp3 C-H sites enabled by the presence of native amides. This protocol is characterized its mild conditions and wide scope, including challenging substrate combinations. Site-selectivity can be dictated a judicious choice ligand, thus offering opportunity to enable bond formations are otherwise inaccessible in conventional events.

Language: Английский

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Nickel Chain-Walking Catalysis: A Journey to Migratory Carboboration of Alkenes

Accounts of Chemical Research, Journal Year: 2023, Volume and Issue: 56(22), P. 3246 - 3259

Published: Nov. 1, 2023

ConspectusChain-walking offers extensive opportunities for innovating synthetic methods that involve constructing chemical bonds at unconventional sites. This approach provides previously inaccessible retrosynthetic disconnections in organic synthesis. Through chain-walking, transition metal-catalyzed alkene difunctionalization reactions can take place a 1,n-addition (n ≠ 2) mode. Unlike classical 1,2-regioselective reactions, there remains scarcity of reports regarding migratory patterns. Moreover, the range olefins utilized these studies is quite limited.About five years ago, our research group embarked on project aimed developing valuable alkenes through chain-walking. Our focus was carboboration utilizing nickel catalysis. The reaction commences with insertion an olefin into Ni-Bpin species. Subsequently, thermodynamically stable alkyl complex generated chain-walking process. then couples carbon-based electrophile, leading to formation alkylboron compound. It worth highlighting success transformations relies significantly utilization bisnitrogen-based ligand and LiOMe as B2pin2 activator. Synthetically, establish robust platform rapid efficient synthesis wide structurally diverse organoboron compounds, which are not facially accessed by conventional methods. incorporation versatile boron introduces wealth possibilities subsequent diversifications, enhancing value resulting products allowing creation broader derivatives applications.This Account comprehensive overview efforts advancements field unactivated using We begin outlining development series 1,1-regioselective terminal alkenes. A significant placed initial integration boronate, only triggers metal species but also exerts control over remote stereochemistry involving substituted methylenecyclohexenes. Continuing exploration, remarkable achieved 1,3-regio- cis-stereoselectivity when dealing cyclic Remarkably, catalysis enables heterocyclic be viable coupling partners within transformations. it grants us ability achieve regioselectivity cyclohexenes unattainable, thus expanding horizons regiochemical reactions. Lastly, we present evolution ligand-modulated regiodivergent allylarenes. By gaining insights underlying mechanisms driving regiodivergence, lay strong foundation tackling challenges related selecting specific sites especially multiple factors. anticipate findings, coupled mechanistic we've gained, will advance realm contribute understanding selectivity this nature. advancement catalyze intricate functional molecules, contributing compounds chemistry.

Language: Английский

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Catalysis with Diboron(4)/Pyridine: Application to the Broad-Scope [3 + 2] Cycloaddition of Cyclopropanes and Alkenes

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(19), P. 8870 - 8882

Published: May 9, 2022

In contrast to the extensive but non-recyclable use of tetraalkoxydiboron(4) compounds as stoichiometric reagents in diverse reactions, this article reports an atom-economical reaction using a commercial diboron(4) catalyst. The key success was designing catalytic cycle for radical [3 + 2] cycloaddition involving pyridine cocatalyst generate from catalyst and reversibly mediate transfer boronyl radicals. comparison with known transition metal-based catalysts, current features not only metal-free conditions, inexpensive stable simple operation also remarkably broadened substrate scope. particular, previously unusable cyclopropyl ketones without activating group and/or alkenes 1,2-disubstitution 1,1,2-trisubstitution patterns were successfully used first time. Consequently, challenging cyclopentane various levels substitution (65 examples, 57 new products, up six substituents at all five ring atoms) readily prepared generally high excellent yield diastereoselectivity. applied concise formal synthesis anti-obesity drug building natural product-like complex bridged or spirocyclic compounds. Mechanistic experiments computational investigation support proposed relay catalysis featuring pyridine-assisted Overall, work demonstrates approach catalysts may lead development new, green, efficient metal-like boron-catalyzed organic reactions.

Language: Английский

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Selective Coupling of 1,2‐Bis‐Boronic Esters at the more Substituted Site through Visible‐Light Activation of Electron Donor–Acceptor Complexes

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(18)

Published: Feb. 25, 2022

1,2-Bis-boronic esters are useful synthetic intermediates particularly as the two boronic can be selectively functionalized. Usually, less hindered primary ester reacts, but herein, we report a coupling reaction that enables reversal of this selectivity. This is achieved through formation boronate complex with an electron-rich aryllithium which, in presence electron-deficient aryl nitrile, leads to electron donor-acceptor complex. Following visible-light photoinduced transfer, radical generated which isomerizes more stable secondary before radical-radical arene radical-anion, giving β-aryl products. The reactions proceed under catalyst-free conditions. method also allows stereodivergent cyclic cis-1,2-bis-boronic provide trans-substituted products, complementing selectivity observed Suzuki-Miyaura reaction.

Language: Английский

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Ni-Catalyzed Radical-Promoted Defluoroalkylborylation of Trifluoromethyl Alkenes To Access gem-Difluorohomoallylic Boronates

Organic Letters, Journal Year: 2022, Volume and Issue: 24(12), P. 2446 - 2451

Published: March 21, 2022

gem-Difluoroalkenyl boronates are attractive synthons for constructing diverse gem-difluoroalkenes and organoboron compounds. However, the strategies construction of gem-difluorohomoallyl has scarcely been described. Herein, we develop an efficient protocol gem-difluorohomoallylic through a Ni-catalyzed radical-promoted defluoroalkylborylation α-trifluoromethyl alkenes with α-haloboronates under mild conditions. This reaction features broad substrate scope good functional group tolerance transformations.

Language: Английский

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Modularity in the C_sp3 Space─Alkyl Germanes as Orthogonal Molecular Handles for Chemoselective Diversification

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(9), P. 4833 - 4839

Published: April 8, 2022

To meet the need for a rapid, streamlined, and potentially automatable molecule synthesis, modular coupling approaches are highly desired. While diversification of aromatic molecules, i.e., Csp2 space, has greatly advanced, syntheses in Csp3 space comparably much less developed. This report explores potential alternative functional handles, alkyl germanes, this context, which combine features stability synthesizability with selective reactivity. We show chemoselective functionalization germanes (R-GeEt3) under photoredox conditions (Giese addition) implementation building block, allows Csp3-halogen vs Csp3-Bpin Csp3-GeEt3 sites.

Language: Английский

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Comproportionation and disproportionation in nickel and copper complexes

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 52(19), P. 6601 - 6616

Published: Jan. 1, 2023

This review covers factors that contribute to comproportionation and disproportionation reactions in transition metal complexes provide insight into the importance of these electron transfer events Ni- Cu-catalyzed transformations.

Language: Английский

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Palladium‐Catalyzed Cascade Heck Coupling and Allylboration of Iododiboron Compounds via Diboryl Radicals

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(18)

Published: March 6, 2024

Geminal bis(boronates) are versatile synthetic building blocks in organic chemistry. The fact that they predominantly serve as nucleophiles the previous reports, however, has restrained their potential. Herein we disclose ambiphilic reactivity of α-halogenated geminal bis(boronates), which first catalytic utilization was accomplished by merging a formal Heck cross-coupling with highly diastereoselective allylboration aldehydes or imines, providing new avenue for rapid assembly polyfunctionalized boron-containing compounds. We demonstrated this cascade reaction is efficient and compatible various functional groups, wide range heterocycles. In contrast to classical Pd(0/II) scenario, mechanistic experiments DFT calculations have provided strong evidence cycle involving Pd(I)/diboryl carbon radical intermediates.

Language: Английский

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Silylarylation of Alkenes via meta-Selective C–H Activation of Arenes under Ruthenium/Iron Cooperative Catalysis: Mechanistic Insights from Combined Experimental and Computational Studies

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(7), P. 4510 - 4522

Published: March 12, 2024

Organosilicons are privileged skeletons in the domains of pharmaceutical chemistry, organic synthesis, and materials science. Hence, investigating catalytic techniques for synthesis organosilicon compounds has received a great deal emphasis. Carbosilylation alkenes is an efficient technique to introduce diverse molecular architectures containing silicon into chemical space. However, organohalides pseudohalides prerequisites most existing carbosilylation protocols. On other hand, utilization C–H activation been sowing seeds successful development intricate scaffolds. In this regard, synthetic accessibility complexed derivatives by through meta-C–H approach remained intangible. Herein, we present three-component strategy arylsilylation olefins with (het)arenes silanes integrating iron-catalyzed silyl radical generation, coupled intrinsic reactivity alkene, ruthenium-catalyzed functionalization (het)arene, leading targeted cross-coupled carbosilylated product. addition, theoretical investigations state-of-the-art dispersion corrected density functional theory at B3PW91-D3/Def2TZVP/CPCM(PhCF3) shed intriguing insights on selectivity probable mechanistic pathway underexplored cooperative 3d/4d transition metal catalysis, such as formation its addition alkene catalyzed iron, followed meta-selective ruthenium bound arene, furnishing C4 substituted (het)arene functionalized compounds.

Language: Английский

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