Synergistic Bimetallic Ni/Ag and Ni/Cu Catalysis for Regioselective γ,δ-Diarylation of Alkenyl Ketimines: Addressing β-H Elimination by in Situ Generation of Cationic Ni(II) Catalysts DOI

Prakash Basnet,

Shekhar KC,

Roshan K. Dhungana

et al.

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(46), P. 15586 - 15590

Published: Nov. 5, 2018

We disclose unprecedented synergistic bimetallic Ni/Ag and Ni/Cu catalysts for regioselective γ,δ-diarylation of unactivated alkenes in simple ketimines with aryl halides arylzinc reagents. The synergy, which generates cationic Ni(II) species during reaction, promotes migratory insertion transmetalation steps suppresses β-H elimination cross-coupling, the major side reactions that cause serious problems alkene difunctionalization. This diarylation reaction proceeds at remote locations to imines afford, after H+ workup, diversely substituted γ,δ-diaryl ketones are otherwise difficult access readily existing methods.

Language: Английский

Nickel-Catalyzed Dicarbofunctionalization of Alkenes DOI

Xiaoxu Qi,

Tianning Diao

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(15), P. 8542 - 8556

Published: July 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.

Language: Английский

Citations

378

Intermolecular radical carboamination of alkenes DOI Creative Commons
Heng Jiang, Armido Studer

Chemical Society Reviews, Journal Year: 2020, Volume and Issue: 49(6), P. 1790 - 1811

Published: Jan. 1, 2020

Vicinal alkene carboamination is a highly efficient and practical synthetic strategy for the straightforward preparation of diverse valuable amine derivatives starting from simple compounds. During last decade that approach has found continuous research interests various methods have been developed using transition-metal catalysis. Driven by renaissance radical chemistry, intermolecular comprising C-C bond C-N forming step intensively investigated recently culminating in novel strategies improved protocols which complement existing methodologies. Radical can be achieved via three different reaction modes. Such cascades proceed through N-radical addition to an with subsequent formation leading 2,1-carboamination products. Alternatively, installed prior initial C-radical β-amination resulting 1,2-carboamination. The third mode comprises single electron oxidation corresponding cation gets trapped N-nucleophile cascade terminated formation. In this review, conceptual approaches will discussed examples recent literature presented. Further, reader get insights into mechanism transformations.

Language: Английский

Citations

365

Mechanisms of Nickel-Catalyzed Coupling Reactions and Applications in Alkene Functionalization DOI
Justin B. Diccianni, Qiao Lin, Tianning Diao

et al.

Accounts of Chemical Research, Journal Year: 2020, Volume and Issue: 53(4), P. 906 - 919

Published: April 2, 2020

ConspectusNickel complexes exhibit distinct properties from other group 10 metals, including a small nuclear radius, high paring energy, low electronegativity, and redox potentials. These enable Ni catalysts to accommodate stabilize paramagnetic intermediates, access radical pathways, undergo slow β-H elimination. Our research program investigates how each of these fundamental attributes impact the catalytic Ni, in particular context alkene functionalization.Alkenes are versatile functional groups, but stereoselective carbofunctionalization reactions alkenes have been underdeveloped. This challenge may derive difficulty controlling selectivity via traditional two-electron migratory insertion pathways. could lead different stereodetermining steps mechanisms, allowing molecular scaffolds that otherwise difficult prepare. For example, an asymmetric diarylation reaction developed by our relies upon Ni(III) intermediates control enantioselectivity give library chiral α,α,β-triarylethane molecules with biological activity.Mechanistic studies on two-component reductive 1,2-difunctionalization shed light origin cross-electrophile selectivity, as C sp2 sp3 electrophiles independently activated at Ni(I) respectively. Catalyst reduction has identified be turnover-limiting step this system. A closer investigation formation using (Xantphos)Ni(I)Ar model complex reveals initiates concerted halogen-abstraction pathway.The potentials allowed us develop reductive, trans-selective diene cyclization, wherein classic mechanism operates Ni(I)/Ni(III) platform, accounting for chemo- stereoselectivity. found applications efficient synthesis pharmaceutically relevant molecules, such 3,4-dimethylgababutin.The tendency one-electron processes prompted explore dinuclear Ni-mediated bond formations. provide insight into Ni–Ni bonding two metal centers react cooperatively promote C–C, C–X, N–N forming elimination.Finally, isolation β-agostic Pd X-ray neutron diffraction characterization highly reactive molecules. The parameters serve unambiguous evidence interactions help rationalize slower elimination relative Pd. Overall, elucidated several contexts. Greater mechanistic understanding facilitates catalyst design helps reactivity Ni-catalyzed functionalization reactions.

Language: Английский

Citations

356

Ni-Catalyzed Enantioselective Reductive Diarylation of Activated Alkenes by Domino Cyclization/Cross-Coupling DOI

Kuai Wang,

Zhengtian Ding,

Zhijun Zhou

et al.

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(39), P. 12364 - 12368

Published: Sept. 20, 2018

A Ni-catalyzed enantioselective reductive diarylation of activated alkenes by domino cyclizative/cross-coupling two aryl bromides is developed. This reaction proceeds under very mild conditions and shows broad substrate scope, without requiring the use preformed organometallic reagents. Moreover, this approach provides direct access to various bis-heterocycles bearing all-carbon quaternary centers in synthetically useful yields (up 81%) with excellent enantioselectivity (>30 examples, 90–99% ee).

Language: Английский

Citations

277

Nickel‐Catalyzed Asymmetric Reductive Diarylation of Vinylarenes DOI

David R. Anthony,

Qiao Lin,

Judith Baudet

et al.

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(10), P. 3198 - 3202

Published: Jan. 25, 2019

Abstract A nickel‐catalyzed asymmetric diarylation reaction of vinylarenes enables the preparation chiral α,α,β‐triarylated ethane scaffolds, which exist in a number biologically active molecules. The use reducing conditions with aryl bromides as coupling partners obviates need for stoichiometric organometallic reagents and tolerates broad range functional groups. application an N ‐oxyl radical ligand to nickel catalyst represents novel approach facilitate cross‐coupling reactions.

Language: Английский

Citations

248

Enantioselective Three-Component Fluoroalkylarylation of Unactivated Olefins through Nickel-Catalyzed Cross-Electrophile Coupling DOI
Hai‐Yong Tu, Fang Wang,

Liping Huo

et al.

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(21), P. 9604 - 9611

Published: May 11, 2020

A nickel-catalyzed, enantioselective, three-component fluoroalkylarylation of unactivated alkenes with aryl halides and perfluoroalkyl iodides has been described. This cross-electrophile coupling protocol utilizes a chiral nickel/BiOx system as well pendant chelating group to facilitate the challenging three-component, asymmetric difunctionalization alkenes, providing direct access valuable β-fluoroalkyl arylalkanes high efficiency excellent enantioselectivity. The mild conditions allow for broad substrate scope good functional toleration.

Language: Английский

Citations

241

Catalytic three-component dicarbofunctionalization reactions involving radical capture by nickel DOI
Shengqing Zhu, Xian Zhao, Huan Li

et al.

Chemical Society Reviews, Journal Year: 2021, Volume and Issue: 50(19), P. 10836 - 10856

Published: Jan. 1, 2021

The catalytic dicarbofunctionalization of unsaturated π bonds represents a powerful platform for the rapid construction complex motifs. Despite remarkable progress, novel and efficient methods achieving such transformations under milder conditions with chemo-, regio-, stereoselectivity still remain significant challenge; thus, their development is highly desirable. Recently, merging nickel catalysis radical chemistry offers new benign unprecedented reactivity selectivity. In this review, we summarize recent advances in area by underpinning domino involving capture to provide clear overview reaction designs mechanistic scenarios.

Language: Английский

Citations

240

Transition Metal (Ni, Cu, Pd)-Catalyzed Alkene Dicarbofunctionalization Reactions DOI

Laura M. Wickham,

Ramesh Giri

Accounts of Chemical Research, Journal Year: 2021, Volume and Issue: 54(17), P. 3415 - 3437

Published: Aug. 12, 2021

ConspectusRecently, alkene dicarbofunctionalization, i.e., the powerful organic synthesis method of difunctionalization with two carbon sources, emerged as a formidable reaction immense promise to synthesize complex molecules expeditiously from simple chemicals. This is generally achieved transition metals (TMs) through interception by sources an alkylmetal [β-H–C(sp3)–[M]] species, key intermediate prone undergo rapid β-H elimination. Related prior reports, since Paolo Chiusoli and Catellani's work in 1982 [ Tetrahedron Lett. 1982, 23, 4517], have used bicyclic disubstituted terminal alkenes, wherein elimination avoided geometric restriction or complete lack β-H's. With reasoning that β-H–C(sp3)–[M] intermediates could be rendered amenable use first row late TMs formation coordination-assisted transient metallacycles, these strategies were implemented address problem dicarbofunctionalization reactions.Because catalyze C(sp3)–C(sp3) coupling, Cu Ni anticipated impart sufficient stability intermediates, generated catalytically upon carbometalation, for their subsequent electrophiles/nucleophiles three-component reactions. Additionally, such innate property enable coupling partners entropically driven cyclization/coupling The cyclometalation concept stabilize intractable was hypothesized when reactions performed. idea curtail founded Whitesides's J. Am. Chem. Soc. 1976, 98, 6521] observation metallacycles much slower than acyclic alkylmetals.In this Account, examples demonstrate catalysts alkenylzinc reagents, alkyl halides, aryl halides afford carbo- heterocycles. In addition, forming nickellacycles enabled regioselective performance various alkenyl compounds. situ [M]-H alkenes after induced unprecedented metallacycle contraction process, which six-membered metal-containing rings shrank five-membered cycles, allowing creation new carbon–carbon bonds at allylic (1,3) positions. Applications are discussed.

Language: Английский

Citations

232

Site-Selective Catalytic Deaminative Alkylation of Unactivated Olefins DOI
Shang‐Zheng Sun, Ciro Romano, Rubén Martı́n

et al.

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(41), P. 16197 - 16201

Published: Sept. 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.

Language: Английский

Citations

221

Nickel‐CatalyzedDicarbofunctionalization of Alkenes DOI
Yun‐Cheng Luo, Chang Xu, Xingang Zhang

et al.

Chinese Journal of Chemistry, Journal Year: 2020, Volume and Issue: 38(11), P. 1371 - 1394

Published: June 16, 2020

As a straightforward strategy for rapidly increasing molecular complexity, dicarbofunctionalization of alkenes has attracted substantial interests organic synthesis, medicine chemistry, and materials science. Nickel‐catalyzed cascade dicarbofunctionalizations have been flourished in this area recently, nickel‐mediated radical pathways particularly offer new opportunities conjunctive cross‐couplings with alkyl coupling partners. Herein, we give comprehensive review nickel‐catalyzed through historical perspective, including intermolecular three‐component reactions intramolecular reactions. Among the discussed review, carbometallation/cross‐coupling process addition/cross‐coupling are two major alkenes. The oxidative cyclization 1,2‐metallate shift processes also selectively discussed. These methods overcome limitations associated using noble metals field, providing an efficient access to structurally diversified molecules.

Language: Английский

Citations

193