C–H activation

Nature Reviews Methods Primers, Journal Year: 2021, Volume and Issue: 1(1)

Published: June 17, 2021

Language: Английский

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Enantioselective C−H Activation with Earth‐Abundant 3d Transition Metals

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(37), P. 12803 - 12818

Published: May 11, 2019

Molecular syntheses largely rely on time- and labour-intensive prefunctionalization strategies. In contrast, C-H activation represents an increasingly powerful approach that avoids lengthy of prefunctionalized substrates, with great potential for drug discovery, the pharmaceutical industry, material sciences, crop protection, among others. The enantioselective functionalization omnipresent bonds has emerged as a transformative tool step- atom-economical generation chiral molecular complexity. However, this rapidly growing research area remains dominated by noble transition metals, prominently featuring toxic palladium, iridium rhodium catalysts. Indeed, despite significant achievements, use inexpensive sustainable 3d metals in asymmetric activations is still clearly its infancy. Herein, we discuss remarkable recent progress transformations via organometallic base up to April 2019.

Language: Английский

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Transition-Metal-Catalyzed, Coordination-Assisted Functionalization of Nonactivated C(sp³)–H Bonds

Chemical Reviews, Journal Year: 2021, Volume and Issue: 121(24), P. 14957 - 15074

Published: Oct. 29, 2021

Transition-metal-catalyzed, coordination-assisted C(sp3)–H functionalization has revolutionized synthetic planning over the past few decades as use of these directing groups allowed for increased access to many strategic positions in organic molecules. Nonetheless, several challenges remain preeminent, such requirement high temperatures, difficulty removing or converting groups, and, although metals provide some reactivity, employing outside palladium. This review aims give a comprehensive overview coordination-assisted, transition-metal-catalyzed, direct nonactivated bonds by covering literature since 2004 order demonstrate current state-of-the-art methods well limitations. For clarity, this been divided into nine sections transition metal catalyst with subdivisions type bond formation. Synthetic applications and reaction mechanism are discussed where appropriate.

Language: Английский

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Chiral Cyclopentadienyl Ligands: Design, Syntheses, and Applications in Asymmetric Catalysis

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(24), P. 13198 - 13224

Published: July 16, 2020

The creation of new chiral ligands capable providing high stereocontrol in metal-catalyzed reactions is crucial modern organic synthesis. production bioactive molecules as single enantiomers increasingly required, and asymmetric catalysis with metal complexes constitutes one the most efficient synthetic strategies to access optically active compounds. Herein we offer a historical overview on development derivatives ubiquitous cyclopentadienyl ligand (CpX ), detail their successful application broad range transformations. Those include functionalization challenging C-H bonds beyond, giving an extensive catalogue valuable molecules. A critical comparison existing families, design, synthesis, complexation different metals also provided. In addition, future research directions are discussed further enhance performance CpX enantioselective catalysis.

Language: Английский

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Enantioselective C H Bond Functionalizations by 3d Transition-Metal Catalysts

Trends in Chemistry, Journal Year: 2019, Volume and Issue: 1(5), P. 471 - 484

Published: April 20, 2019

Language: Английский

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Diverse Approaches for Enantioselective C−H Functionalization Reactions Using Group 9 Cp^xM^III Catalysts

Chemistry - A European Journal, Journal Year: 2020, Volume and Issue: 26(33), P. 7346 - 7357

Published: Jan. 29, 2020

Transition-metal-catalyzed C-H functionalization reactions with Cp*MIII catalysts (M=Co, Rh, Ir) have found a wide variety of applications in organic synthesis. Albeit the intrinsic difficulties achieving catalytic stereocontrol using these due to their lack additional coordination sites for external chiral ligands and conformational flexibility Cp ligand, enantioselective Group 9 metal triad Cp-type been intensively studied since 2012. In this minireview, progress according type catalyst used are summarized discussed. The development Cpx complexes thereof, artificial metalloenzymes, carboxylate-assisted activations, alkylations assisted by carboxylic acids or sulfonates, transient directing groups

Language: Английский

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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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Dioxazolones: Stable Substrates for the Catalytic Transfer of Acyl Nitrenes

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(8), P. 4751 - 4769

Published: March 30, 2020

Dioxazolones are a convenient class of acyl nitrene transfer reagents. Their application in homogeneous transition-metal catalysis has led to many new amidation reactions. typically activated by transition metals at relatively low reaction temperatures. The metal nitrenoids formed decarboxylative activation dioxazolones generally electron deficient and commonly react concerted fashion. "Intermolecular" insertion reactions involving preactivated C–H bonds ("inner-sphere" mechanism) easily compete with the Curtius-type rearrangement, but for intramolecular "direct" transfer/insertion nonpreactivated substrates (i.e., without preceding formation metal–carbon or metal–hydride bonds) extensive ligand optimization is important prevent such unwanted side ease dioxazolone synthesis, CO2 gas as sole byproduct from dioxazolones, importance general development several interesting producing N-aryl amides, oxazoles, lactams. Since proceeds under mild conditions, stereo- enantioselective also possible, which useful synthesis bioactive nitrogen-containing compounds. This review provides an overview these reported recent years.

Language: Английский

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Mechanism-Guided Development of Transition-Metal-Catalyzed C–N Bond-Forming Reactions Using Dioxazolones as the Versatile Amidating Source

Accounts of Chemical Research, Journal Year: 2021, Volume and Issue: 54(11), P. 2683 - 2700

Published: May 12, 2021

ConspectusCatalytic reactions that construct carbon–nitrogen bonds are one of central themes in both synthetic and medicinal chemistry since the obtainable nitrogen-containing motifs commonly encountered natural products have also seen a growing prominence as key structural features marketed drugs preclinical candidates. Pd-catalyzed cross-couplings, such Buchwald–Hartwig amination, at forefront methods practical settings. However, they require prefunctionalized substrates (hetero)aryl halides must be prepared independently, often by multiple operations. One emerging way to circumvent these preparatory steps directly convert ubiquitous C–H into valuable C–N is catalytic which allows chemists devise shorter more efficient retrosynthetic schemes. The past two decades witnessed considerable progress expanding repertoire this strategy, especially identifying effective amino group precursors. In context, dioxazolones experienced dramatic resurgence recent years versatile nitrogen source combination with transition-metal catalyst systems facilitate decarboxylation access metal-acylnitrenoid intermediates. addition their high robustness easy accessibility from abundant carboxylic acids, unique reactivity transient intermediates amido transfer has led fruitful journey for mild amidation reactions.This Account summarizes our contributions development bond-forming using nitrenoid precursors, categorized subsets according mechanistic differences: inner- versus outer-sphere pathways. first section describes how we could unveil potential realm inner-sphere amidation, where demonstrated serve not only manageable alternatives acyl azides but highly reagents significantly reduce loading temperature. Taking advantage conditions 9 Cp*M complexes (M = Rh, Ir, Co) or isoelectronic Ru species, dramatically expanded accessible scope. Mechanistic investigations revealed putative metal-nitrenoid species involved intermediate during catalysis, leads facile bond formation. On basis underpinning, succeeded developing novel platforms harness intermediacy metal-nitrenoids explore insertion via an pathway. Indeed, tailored catalysts were capable suppressing competitive Curtius-type decomposition, thus granting lactam products. We further repurposed upon modification chelating ligands identity transition metal achieve three goals: (i) addressing selectivity issues control regio-, chemo-, enantioselectivities, (ii) sustainable catalysis first-low metals, (iii) navigating chemical space (di)functionalization alkenes/alkynes. Together own research efforts, highlighted herein some important relevant advances other groups. finally conclude brief overview eye toward developments.

Language: Английский

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Nitrene transfer catalysts for enantioselective C–N bond formation

Nature Reviews Chemistry, Journal Year: 2021, Volume and Issue: 5(8), P. 580 - 594

Published: June 28, 2021

Language: Английский

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