Trialkoxysilane-Induced Iridium-Catalyzed para-Selective C–H Bond Borylation of Arenes

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: April 2, 2024

Abstract An ideal approach for the construction of aryl boron compounds is to selectively replace a C–H bond in arenes with C–B bond, and controlling regioselectivity one most challenging aspects these transformations. Herein, we report an iridium-catalyzed trialkoxysilane protecting group-assisted regioselective borylation arenes, including derivatives benzaldehydes, acetophenones, benzoic acids, benzyl alcohols, phenols, silanes, multi-functionalized aromatic rings are all well tolerated gave para - selective products short time without requirement inert gases atmosphere. The site-selective can be adjustable by installing developed group on different functional groups ring. Importantly, preparation process trialkoxychlorosilane efficient scalable. Mechanistic computational studies reveal that steric hindrance plays key role dictating -selectivity.

Language: Английский

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Photochemical C–H Borylation in Organic Synthesis

ACS Catalysis, Journal Year: 2025, Volume and Issue: 15(3), P. 1753 - 1770

Published: Jan. 16, 2025

Although C–H bond functionalization has been extensively studied since its discovery in 1955, the borylation of organic compounds by activating bonds only became popular valuable Hartwig 1995 who considered a wider application these transformations synthetic chemistry. For borylation, catalytic activation this generally low-reactivity can be performed many ways. Among approaches reported are use and stoichiometric reagents, thermal activation, photochemical suitable substrates. Iridium-, ruthenium-, rhodium-based protocols using have played crucial role toward establishment area. Photochemical though, scarcely explored despite fact that it represents comparably environmentally benign protocol light as renewable energy source. In literature survey, we highlight recent developments from initial inception up to latest advancements.

Language: Английский

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Electrochemical Borylation of C−C and C−Het Bonds

ChemElectroChem, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 19, 2025

Abstract Recently, electrochemical methods have been harnessed as a transition metal‐free strategy for borylation reactions in the synthesis of organoboron compounds. This article reviews C−C and C−Het bonds, offering systematic discussion C−C, C−N, C−O, C−S bond reactions. These transformations are applied to substrates including ammonium salts, aryl azo sulfones, carboxylic acids, arylhydrazines, nitroarenes, alcohols, thioethers, showcasing broad compatibility. Additionally, review discusses reaction mechanisms, scalability, practical applications these strategies. The concludes by outlining future research directions reactions, aiming at expending their incorporating boron into wider array organic compounds, challenging unactivated C−F borylations.

Language: Английский

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Ir-Catalyzed, Nitrogen-Directed C(sp³)–H and C(sp²)–H Borylation with a Spiro-Fluorene-Indenoindenyl Ligand

ACS Catalysis, Journal Year: 2025, Volume and Issue: unknown, P. 4061 - 4068

Published: Feb. 21, 2025

Language: Английский

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Bis-CF₃-bipyridine Ligands for the Iridium-Catalyzed Borylation of N-Methylamides

ACS Catalysis, Journal Year: 2025, Volume and Issue: unknown, P. 7112 - 7120

Published: April 16, 2025

Language: Английский

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The Role of Boron Reagents in Determining the Site-Selectivity of Pyridine(dicarbene) Cobalt-Catalyzed C–H Borylation of Fluorinated Arenes

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: April 17, 2025

The origin of the meta- and ortho-to-fluorine site-selectivity in C(sp2)-H borylation fluorinated arenes with B2Pin2 HBPin promoted by pyridine(dicarbene)cobalt catalysts has been investigated. In situ generation cobalt(I)-boryl complex treatment three representative fluoroarenes established meta-selective oxidative addition to form predominantly meta isomers corresponding cobalt(I)-aryl complexes. Attempts observe or isolate four-coordinate yielded cobalt-hydride dimer, [(iPrACNC)CoH]2, borohydride (iPrACNC)CoH2BPin, diboryl hydride, (iPrACNC)CoH(BPin)2 depending on amounts present. phosphite derivatives (iPrACNC)CoH(P(OiPr)3) (iPrACNC)CoBPin(P(OiPr)3) were prepared crystallographically characterized. catalytic 1,3-difluorobenzene, complexes identified as resting states despite meta-to-fluorine being major product catalysis. Deuterium kinetic isotope effects support irreversible but not turnover-limiting addition. Stoichiometric isolated intermediates that meta-cobalt(I)-aryl was more reactive than ortho-isomer accounts for observed states. All compounds reacted quickly HBPin. While ortho-cobalt(I)-aryl arylboronate products high site-selectivity, meta-cobalt-aryl counterparts a mixture free arene. labeling experiments DBPin confirmed mediates reversible Thus, overall arises from two reinforcing effects: (i) kinetically (ii) faster reaction isomer B2Pin2. As is converted HBPin, reductive elimination competes against isomer, resulting increased ortho-selective borylation.

Language: Английский

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Base-free palladium-catalyzed borylation of enol carboxylates and further reactivity toward deboronation and cross-coupling

Tetrahedron, Journal Year: 2025, Volume and Issue: unknown, P. 134682 - 134682

Published: May 1, 2025

Language: Английский

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Repurposing a supramolecular iridium catalyst via secondary Zn⋯OC weak interactions between the ligand and substrate leads to ortho-selective C(sp²)–H borylation of benzamides with unusual kinetics

Chemical Science, Journal Year: 2024, Volume and Issue: 15(30), P. 11794 - 11806

Published: Jan. 1, 2024

Supramolecular catalysts based on a zinc-porphyrin molecular recognition site and catalytically active iridium enabled the selective ortho -C–H borylation of benzamides under regime in which C–H activation step is not rate-determining.

Language: Английский

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Transition Metal-Free Catalytic C−H Zincation and C−H Alumination

Published: Feb. 23, 2024

C−H metalation is the most efficient method to prepare aryl–zinc and –aluminum complexes that are highly useful nucleophiles. Virtually all C–H routes form Al or Zn organometallic reagents require stoichiometric, strong Brønsted bases with no base-catalyzed reactions reported, our knowledge. Herein we present a catalytic process aryl-zinc aryl-aluminum uses only simple amine (e.g., Et3N) in sub-stoichiometric quantity (10 mol%). Key this approach coupling an endergonic step using [(-diketiminate)MNR3]+ (M = Al–Me) electrophile sufficiently exergonic dehydrocoupling between acidic ammonium salt by-product of ([(R3N)H]+) Zn–H Al–Me containing complex. This step, forming H2/MeH, makes overall cycle while also generating more key cationic metal electrophile. Mechanistic studies supported by DFT calculations revealed metal-specific pathways, divergent reactivity shown be due different valency (which impacts accessibility amine-free complexes) steric environment. Notably, zinc system proceeds through ligand-mediated pathway involving protonation -diketiminate C position. In magnitude barrier dependent on bulk spectator ligand, bulkier ligands actually affording lower barriers. arene has potential applicable other main group metals ligands, thus will facilitate synthesis these important compounds.

Language: Английский

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Ir-Catalyzed Borylation of Heterocycles Through C−H Activation

Topics in heterocyclic chemistry, Journal Year: 2024, Volume and Issue: unknown, P. 159 - 210

Published: Jan. 1, 2024

Language: Английский

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