Walking Metals for Remote Functionalization

ACS Central Science, Год журнала: 2018, Номер 4(2), С. 153 - 165

Опубликована: Фев. 8, 2018

The distant and selective activation of unreactive C–H C–C bonds remains one the biggest challenges in organic chemistry. In recent years, development remote functionalization has received growing interest as it allows for rather challenging from initiation point by means a "metal-walk". A "metal-walk" or "chain-walk" is defined an iterative series consecutive 1,2- 1,3-hydride shifts metal complex along single hydrocarbon chain. With this approach, simple building blocks mixtures thereof can be transformed into scaffolds convergent unified strategy. variety catalytic systems have been developed refined over past decade ranging late-transition-metal complexes to more sustainable iron- cobalt-based systems. As possibilities field are slowly unfolding, area research will contribute considerably provide solutions yet unmet synthetic challenges.

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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Site-Selective Ni-Catalyzed Reductive Coupling of α-Haloboranes with Unactivated Olefins

Journal of the American Chemical Society, Год журнала: 2018, Номер 140(40), С. 12765 - 12769

Опубликована: Сен. 23, 2018

A mild, chemo- and site-selective catalytic protocol that allows for incorporating an alkylboron fragment into unactivated olefins is described. The use of internal enables C–C bond-formation at remote sp3 C–H sites, constituting a complementary conceptually different approach to existing borylation techniques are currently available centers.

Язык: Английский

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Mechanism of Ni-Catalyzed Reductive 1,2-Dicarbofunctionalization of Alkenes

Journal of the American Chemical Society, Год журнала: 2019, Номер 141(44), С. 17937 - 17948

Опубликована: Окт. 7, 2019

Ni-catalyzed cross-electrophile coupling reactions have emerged as appealing methods to construct organic molecules without the use of stoichiometric organometallic reagents. The mechanisms are complex: plausible pathways, such "radical chain" and "sequential reduction" mechanisms, dependent on sequence activation electrophiles. A combination kinetic, spectroscopic, studies reveals that a Ni-catalyzed, reductive 1,2-dicarbofunctionalization alkenes proceeds through pathway. reduction Ni by Zn is turnover-limiting step, consistent with Ni(II) intermediates catalyst resting-state. only sufficient reduce (phen)Ni(II) Ni(I) species. As result, commonly proposed Ni(0) absent under these conditions. (Phen)Ni(I)–Br selectively activates aryl bromides via two-electron oxidation addition, whereas alkyl activated (phen)Ni(I)–Ar single-electron afford radicals. These findings could provide insight into achieving selectivity between different

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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Nickel-catalyzed allylic defluorinative alkylation of trifluoromethyl alkenes with reductive decarboxylation of redox-active esters

Chemical Science, Год журнала: 2018, Номер 10(3), С. 809 - 814

Опубликована: Ноя. 7, 2018

Synthesis of functionalized gem-difluoroalkenes was achieved through nickel-catalyzed allylic defluorinative alkylation trifluoromethyl alkenes with reductive decarboxylation redox-active esters.

Язык: Английский

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Remote sp3 C–H Amination of Alkenes with Nitroarenes

Chem, Год журнала: 2018, Номер 4(7), С. 1645 - 1657

Опубликована: Май 17, 2018

Язык: Английский

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NiH‐Catalyzed Remote Asymmetric Hydroalkylation of Alkenes with Racemic α‐Bromo Amides

Angewandte Chemie International Edition, Год журнала: 2018, Номер 58(6), С. 1754 - 1758

Опубликована: Дек. 12, 2018

Reported here is a terminal-selective, remote asymmetric hydroalkylation of olefins with racemic α-bromo amides. The reaction proceeds by NiH-catalyzed alkene isomerization and subsequent alkylation reaction, can enantioconvergently introduce an unsymmetrical secondary alkyl group from amide onto terminal C(sp3 )-H position along the hydrocarbon chain alkene. This mild process affords range structurally diverse chiral α-alkylalkanoic amides in excellent yields, high regio- enantioselectivities. In addition, synthetic utility this protocol further highlighted regioconvergent conversion industrial raw materials isomeric olefin mixtures into enantioriched on large scale.

Язык: Английский

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Nickel‐Catalyzed Electrochemical Reductive Relay Cross‐Coupling of Alkyl Halides to Aryl Halides

Angewandte Chemie International Edition, Год журнала: 2019, Номер 59(16), С. 6520 - 6524

Опубликована: Дек. 3, 2019

A highly regioselective Ni-catalyzed electrochemical reductive relay cross-coupling between an aryl halide and alkyl has been developed in undivided cell. Various functional groups are tolerated under these mild reaction conditions, which provides alternative approach for the synthesis of 1,1-diarylalkanes.

Язык: Английский

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Tackling Remote sp³ C−H Functionalization via Ni‐Catalyzed “chain‐walking” Reactions

Israel Journal of Chemistry, Год журнала: 2019, Номер 60(3-4), С. 195 - 206

Опубликована: Авг. 21, 2019

Abstract Nickel catalysts have recently played an important role for rapidly and reliably converting feedstock chemicals into valuable compounds of interest both pharmaceutical academic laboratories. Herein, we summarize the recent advances on ability nickel to trigger olefin isomerization via “chain‐walking”, causing a displacement catalyst throughout alkyl chain while opening up new grounds forging C−C C‐heteroatom linkages at remote, yet unfunctionalized, sp 3 C−H bonds.

Язык: Английский

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