Chiral Cyclopentadienyl Cobalt(III) Complexes Enable Highly Enantioselective 3d-Metal-Catalyzed C–H Functionalizations

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(14), P. 5675 - 5680

Published: March 22, 2019

The synthesis of a set cobalt(III)-complexes equipped with trisubstituted chiral cyclopentadienyl ligands is reported, and their steric electronic parameters are mapped. application potential these complexes for asymmetric C-H functionalizations 3d-metals shown by the dihydroisoquinolones from N-chlorobenzamides broad range alkenes. transformation proceeds excellent enantioselectivities up to 99.5:0.5 er high regioselectivities. observed values outperform best rhodium(III)-based methods this reaction type. Moreover, challenging substrates such as alkyl alkenes also react regio- enantioselectivities.

Language: Английский

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Weak-Coordination in C–H Bond Functionalizations Catalyzed by 3d Metals

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(6), P. 3452 - 3506

Published: March 3, 2022

Transition-metal-catalyzed C–H bond functionalizations have had an enormous influence on organic synthesis in recent times. However, the use of low-abundance 4d and 5d metals is almost inevitable, they are high demand. This will be a cause concern, hence, it important to develop methods based 3d metals, which widely present Earth's crust. In this regard, metal catalysts or their precursors for catalysis, general, functionalizations, particular, has gained significant momentum The major development catalytic with been achieved predominantly strongly coordinating directing groups such as pyridyl, pyrimidinyl, pyrazolyl, 8-amino-quinolinyl groups. Thus, prefunctionalization substrates these necessary, contradicts step- atom-economy activation. commonly available functional aldehyde, ketone, carboxylic acid, amide, hydroxy, N-oxides loosely bind through weak-coordination. These weakly orient activate regioselectively without need preinstalled Although challenging, contemporary topic actively pursued by many researchers Through article, we provide comprehensive overview metal-catalyzed, coordinating, directing-group-enabled reported until March 2021.

Language: Английский

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Alkylation, Annulation, and Alkenylation of Organic Molecules with Maleimides by Transition‐Metal‐Catalyzed C‐H Bond Activation

Asian Journal of Organic Chemistry, Journal Year: 2019, Volume and Issue: 8(11), P. 1949 - 1969

Published: March 13, 2019

Abstract Maleimide and succinimide core moieties are present in various natural products pharmaceuticals. In addition, these derivatives can be readily modified into biologically important organic molecules including pyrrolidines γ‐lactams. A transition‐metal‐catalyzed chelation‐assisted functionalization of inert C−H bond with electrophiles or nucleophiles is one the efficient methods to construct chemical bonds a highly atom‐ step‐economical manner. The review describes recent advances reaction involving maleimides by activation methodology. having directing groups, such as ketone, acyl, pyridyl, pyrimidyl, oxime, amide, imidate, chromone, azo, N ‐sulfonyl ketimine, carboxylic acids, aldimines, were described. scope, limitation mechanistic investigation alkylation, annulation alkenylation reactions discussed elaborately. This article includes entire report on bond‐forming strategy until end 2018.

Language: Английский

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Transition metal-catalyzed coupling of heterocyclic alkenesviaC–H functionalization: recent trends and applications

Organic Chemistry Frontiers, Journal Year: 2020, Volume and Issue: 7(12), P. 1527 - 1569

Published: Jan. 1, 2020

Heterocyclic alkenes and their derivatives are an important class of reactive feedstock valuable synthons. This review highlights the transition-metal-catalyzed coupling heterocyclic alkenesviaa C–H functionalization strategy.

Language: Английский

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C–H bond functionalization by high-valent cobalt catalysis: current progress, challenges and future perspectives

Chemical Communications, Journal Year: 2021, Volume and Issue: 57(83), P. 10827 - 10841

Published: Jan. 1, 2021

Over the last decade, high-valent cobalt catalysis has earned a place in spotlight as valuable tool for C-H activation and functionalization. Since discovery of its unique reactivity, more attention been directed towards utilization an alternative to noble metal catalysts. In particular, Cp*Co(III) complexes, well simple Co(II) Co(III) salts combination with bidentate chelation assistance, have extensively used development novel transformations. this review, we demonstrated existing trends functionalization methodology using highlighted main challenges overcome, perspective directions, which need be further developed future.

Language: Английский

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Recent advances in transition metal-catalyzed heteroannulative difunctionalization of alkenes via C–H activation for the synthesis of heterocycles

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(8), P. 2256 - 2279

Published: Jan. 1, 2022

In this review article, we summarized recent advances in the transition metal-catalyzed heteroannulative difunctionalization of alkenes via direct C–H activation to access heterocyclic frameworks.

Language: Английский

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Weak Coordinating Carboxylate Directed Rhodium(III)-Catalyzed C–H Activation: Switchable Decarboxylative Heck-Type and [4 + 1] Annulation Reactions with Maleimides

Organic Letters, Journal Year: 2019, Volume and Issue: 21(12), P. 4525 - 4530

Published: June 10, 2019

A weakly coordinating carboxylate directing group assisted C–H activation with maleimides leading to novel and switchable decarboxylative Heck-type [4 + 1] annulation products catalyzed by Rh(III) has been reported. In these reactions, solvents play a vital role in switching the selectivity. An aprotic solvent, THF, leads product while protic TFE, results product. The methodology shows high functional tolerance.

Language: Английский

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Cobalt-Catalyzed Regioselective Direct C-4 Alkenylation of 3-Acetylindole with Michael Acceptors Using a Weakly Coordinating Functional Group

Organic Letters, Journal Year: 2019, Volume and Issue: 21(19), P. 8138 - 8143

Published: Sept. 23, 2019

Herein, we disclosed the first report on selective C(4)–H functionalization of 3-acetylindole derivatives using first-row transition metal cobalt where an acetyl group is acting as a weakly coordinating directing group. Selective has been achieved diverse Michael acceptors (acrylate and maleimide) simply by switching additive from copper acetate to silver carbonate. Further formation cobaltacycle intermediate was also detected through HRMS for mechanistic insight.

Language: Английский

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Rhodium(III)-Catalyzed Dehydrogenative Annulation and Spirocyclization of 2-Arylindoles and 2-(1H-Pyrazol-1-yl)-1H-indoles with Maleimides: A Facile Access to Isogranulatimide Alkaloid Analogues

The Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 86(3), P. 2328 - 2338

Published: Jan. 12, 2021

A Rh(III)-catalyzed dehydrogenative annulation and spirocyclization of 2-arylindoles 2-(1H-pyrazol-1-yl)-1H-indole with maleimides is described. The cascade protocol provided highly functionalized benzo[a]pyrrolo[3,4-c]carbazole-1,3(2H,8H)-diones spiro[isoindolo[2,1-a]indole-6,3′-pyrrolidine]-2′,5′-diones in good to excellent. developed reaction methodology exhibited broad substrate scope functional group tolerance operationally simple scalable. Photophysical properties the annulated products were investigated. product showed high absorption emission values a large red-shift as compared that 2-phenylindole.

Language: Английский

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Sulfoxonium-Ylide-Directed C–H Activation and Tandem (4 + 1) Annulation

Organic Letters, Journal Year: 2020, Volume and Issue: 22(8), P. 2878 - 2882

Published: March 31, 2020

Rh(III)-catalyzed C-H activation and cyclization of sulfoxonium ylide with acrylates leads to an efficient synthesis indanone derivatives. The reaction proceeds under mild external metal-oxidant-free conditions. acts as a traceless directing group well internal oxidant. (4 + 1) Annulation after the formation carbocyclic ring, byproduct obtained is DMSO, which can be easily separated.

Language: Английский

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