Bidentate Directing Groups: An Efficient Tool in C–H Bond Functionalization Chemistry for the Expedient Construction of C–C Bonds

Chemical Reviews, Journal Year: 2020, Volume and Issue: 120(3), P. 1788 - 1887

Published: Jan. 6, 2020

During the past decades, synthetic organic chemistry discovered that directing group assisted C–H activation is a key tool for expedient and siteselective construction of C–C bonds. Among various strategies, bidentate groups are now recognized as one most efficient devices selective functionalization certain positions due to fact its metal center permits fine, tunable, reversible coordination. The family permit types assistance be achieved, such N,N-dentate, N,O-dentate, N,S-dentate auxiliaries, which categorized based on coordination site. In this review, we broadly discuss bond reactions formation bonds with aid groups.

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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Synthesis of Fused or Spiro Polyheterocyclic Compounds via the Dehydrogenative Annulation Reactions of 2-Arylindazoles with Maleimides

Organic Letters, Journal Year: 2019, Volume and Issue: 21(18), P. 7189 - 7193

Published: Sept. 4, 2019

A dehydrogenative annulation of 2-arylindazoles with maleimides for the switchable synthesis indazolo[2,3-a]pyrrolo[3,4-c]quinolinones or spiroindolo[1,2-b]indazole-11,3′-pyrrolidinones is presented. Mechanistically, formation title compounds involves a Rh(III)-catalyzed C–H metalation 2-arylindazole, followed by maleimide insertion and intramolecular cyclization. Interestingly, selectivity to form fused spiro could be switched resorting different additives. The notable features this protocol include simple substrates excellent atom economy regioselectivity.

Language: Английский

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Decoding Directing Groups and Their Pivotal Role in C−H Activation

Chemistry - A European Journal, Journal Year: 2021, Volume and Issue: 27(49), P. 12453 - 12508

Published: May 26, 2021

Synthetic organic chemistry has witnessed a plethora of functionalization and defunctionalization strategies. In this regard, C-H been at the forefront due to multifarious applications in development simple complex molecular architectures holds brilliant prospect drug discovery. Despite explored tremendously by chemists, strategy still enjoys employment novel metal catalysts as well metal-free ligands. Moreover, switch photo- electrochemistry widened our understanding alternative pathways via which reaction can proceed these strategies have garnered prominence when applied activation. chemists foraging for new directing groups templates selective activation bonds from myriad carbon-hydrogen aromatic aliphatic systems. As matter fact, varying groups, scientists found answer challenge distal bond remained an obstacle very long time. These frequently harnessed selectively activating natural products, drugs, macromolecules decorated with multiple bonds. This itself was before commencement field site other than targeted could modify hamper biological activity pharmacophore. Total synthesis pharmacophore often faces difficulty superfluous steps towards functionalization. solved late-stage simply harnessing green conditions seen light past few decades rising concern about environmental issues. Therefore, or usage non-toxic metals recently showcased number elegant works. Also, research across world are developing rational group free non-directed protocols that just guided review encapsulates works pertinent discusses science devoted it fundamental level. gives readers broad how work, execution various catalysts, groups. not only helps budding scientist his/her but also matured mind searching out A detailed picture its progress time portrayed lucid scientific language motive inculcate educate minds beautiful overview most relevant significant era. The unique trait is description classification their utility over wide substrate scope. allows experimental chemist understand applicability domain employ any substrate.

Language: Английский

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Cobalt‐Catalyzed Oxidative C−H Activation: Strategies and Concepts

ChemSusChem, Journal Year: 2020, Volume and Issue: 13(13), P. 3306 - 3356

Published: Feb. 17, 2020

Inexpensive cobalt-catalyzed oxidative C-H functionalization has emerged as a powerful tool for the construction of C-C and C-Het bonds, which offers unique potential transformative applications to modern organic synthesis. In early stage, these transformations typically required stoichiometric toxic transition metals sacrificial oxidants; thus, formation metal-containing waste was inevitable. contrast, naturally abundant molecular O2 more recently been successfully employed green oxidant in cobalt catalysis, thus considerably improving sustainability such transformations. Recently, significant momentum gained by use electricity sustainable environmentally benign redox reagent functionalization, thereby preventing consumption cost-intensive chemicals while at same time addressing considerable safety hazards related oxygen combination with flammable solvents. Considering unparalleled aforementioned approaches synthesis, this Review summarizes recent progress activation until 2020.

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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Transition Metal Promoted Cascade Heterocycle Synthesis through C−H Functionalization

Chemistry - A European Journal, Journal Year: 2020, Volume and Issue: 26(44), P. 9749 - 9783

Published: June 18, 2020

Sequential, domino and tandem reactions could be defined as a sequence of synthetic transformations that occur one after the other, in same reaction flask. This Review highlights recent advances at overlap two worlds: transition-metal mediated C-H activation trigger cascade reaction, for heterocycles synthesis. To shed some light on this intricate "middle-earth", focus was put mechanism rather than type metal or chronological order reaction. The aim is to separate, then highlight, true initiated by activation, compared other examples functionalization heterocycle syntheses.

Language: Английский

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Synthesis of Chiral Spirolactams via Sequential C−H Olefination/Asymmetric [4+1] Spirocyclization under a Simple Co^II/Chiral Spiro Phosphoric Acid Binary System

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(43), P. 23187 - 23192

Published: Aug. 26, 2021

Abstract An unprecedented enantioselective synthesis of spiro‐γ‐lactams via a sequential C−H olefination/asymmetric [4+1] spirocyclization under simple Co II /chiral spiro phosphoric acid (SPA) binary system is reported. A range biologically important are obtained with high levels enantioselectivity (up to 98 % ee ). The concise, asymmetric an aldose reductase inhibitor was successfully achieved. Notably, contrast previous reports that relied on the use cyclopentadienyl or its derivatives (achiral Cp*, Cp tBu , chiral x ) ligated III complexes requiring tedious steps prepare, cheap and commercially available cobalt(II) acetate tetrahydrate used as efficient precatalyst.

Language: Английский

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Recent advances in spirocyclization of maleimides via transition-metal catalyzed C–H activation

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(15), P. 2916 - 2947

Published: Jan. 1, 2024

In recent years, the maleimide scaffold has received a great deal of attention in C–H activation.

Language: Английский

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Rhodium(III)-Catalyzed Redox-Neutral 1,1-Cyclization ofN-Methoxy Benzamides with Maleimides via C–H/N–H/N–O Activation: Detailed Mechanistic Investigation

The Journal of Organic Chemistry, Journal Year: 2019, Volume and Issue: 84(7), P. 4058 - 4071

Published: Feb. 27, 2019

An Rh(III)-catalyzed 1,1-cyclization of N-methoxy benzamides with maleimides providing isoindolinone spirosuccinimides through N–H/C–H/N–O bond activation is described. The detailed mechanistic investigation including isolation key metalacycle intermediate, deuterium labeling studies, and DFT calculations were performed. computational study reveals that the AcOH formed in reaction medium plays a role N–OMe cleavage oxidation Rh(I) to Rh(III).

Language: Английский

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