Diastereoselective Transfer of Tri(di)fluoroacetylsilanes‐Derived Carbenes to Alkenes

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(25)

Published: April 13, 2022

Stereoselective cyclopropanation reaction of alkenes is usually achieved by metal complexes via singlet-metal-carbene intermediates. However, previous transition-metal-catalyzed with acylsilanes afforded low diastereoselectivity. Herein, we report the first visible-light-induced transition-metal-free terminal trifluoroacetylsilanes and difluoroacetylsilanes. Both aromatic aliphatic as well electron-deficient are suitable substrates for highly cis-selective [2+1] cyclization reaction. A combination experimental computational studies identified triplet carbenes being key intermediates in this transformation. The gram scale late-stage functionalization demonstrated synthetic potential strategy.

Language: Английский

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Palladium-Catalyzed Enantioselective Carbene Insertion into Carbon–Silicon Bonds of Silacyclobutanes

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(33), P. 12968 - 12973

Published: Aug. 12, 2021

We report herein a highly efficient palladium-catalyzed carbene insertion into strained Si–C bonds with excellent enantioselectivity, which provides rapid and distinct method to access silacyclopentanes three- or four-substituted stereocenter asymmetrically. Mechanistic studies using hybrid density functional theory suggest catalytic cycle involving oxidative addition, migratory insertion, reductive elimination. In roles of the chiral ligands in controlling reaction enantioselectivity are also elucidated.

Language: Английский

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Transition metal-catalysed carbene- and nitrene transfer to carbon monoxide and isocyanides

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(14), P. 5842 - 5877

Published: Jan. 1, 2022

Transition metal-catalysed carbene- and nitrene transfer to the C1-building blocks carbon monoxide isocyanides provides heteroallenes (i.e. ketenes, isocyanates, ketenimines carbodiimides). These are versatile reactive compounds allowing in situ transformation towards numerous functional groups organic compounds, including heterocycles. Both one-pot tandem processes have been developed providing valuable synthetic methods for chemistry toolbox. This review discusses all known transition reactions of hereby obtained, with a special focus on general mechanistic considerations.

Language: Английский

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Transition Metal-Catalyzed Regioselective Direct C–H Amidation: Interplay between Inner- and Outer-Sphere Pathways for Nitrene Cross-Coupling Reactions

Accounts of Chemical Research, Journal Year: 2022, Volume and Issue: 55(15), P. 2123 - 2137

Published: July 19, 2022

ConspectusCatalytic C–N bond cross-coupling reactions have been a subject of fundamental importance in synthetic organic and medicinal chemistry because amides amines are ubiquitous motifs natural products, functional materials, pharmaceuticals. Since the pioneering works Breslow Mansuy on metalloporphyrin-catalyzed direct hydrocarbon amidation using sulfonyliminoiodinane reagents, substantial development has achieved toward practical selective amination protocols. Notably, Du Bois's group developed dirhodium(II,II) carboxylate catalytic system for C(sp3)–H amidations via Rh-sulfonyl nitrene intermediates. Yet, this protocol suffers from competitive alkene aziridination is limited to electron-rich tertiary ethereal C–H bonds; analogous arenes remained ineffective.This Account discusses our early effort explore cyclopalladated complexes ortho-selective C(aryl)–H amidations. While Buchwald–Hartwig cannot be directly applied arenes, effective 2-arylpyridines occurred when an external oxidant such as K2S2O8 was employed. Preliminary studies suggested that may proceed through reactive Pd-nitrene Aiming develop more diversified protocols, we employed nosyloxycarbamates precursors Pd-catalyzed ortho-amidation N-pivalanilides. Likewise, benzoic acids produce anthranilic acids, which versatile many medicinally valuable heterocycles. In attempt expand C(aryl)–N coupling amines, studied d6 piano-stool Cp*Rh(III) systems [Cp* = pentamethylcyclopentadienyl]. Our work established sound reaction platform based electrophilic aminating reagents including N-chloroamines, hydroxyamides, N-carboxyhydrazides formation aryl–metal complexes.Building upon metal-nitrene platform, moved forward examine γ-lactam synthesis by intramolecular carbonyl insertion. Noted nitrenes prone undergo Curtius-type rearrangement form isocyanate; found π-basic Ru(II) center effectively decomposes dioxazolones afford regioselective γ-C(sp3)–H With chiral diphenylethylenediamines (dpen) ligands bearing electron-withdrawing arylsulfonyl substituents, [(p-cymene)Ru(dpen)] complex catalyzed decomposition γ-lactams formal Enantioselective insertion allylic propargylic bonds also with remarkable tolerance C═C C≡C bonds. selectivity [(p-cymene)Ru] switched give dihydroquinolinones l-proline ligand. Recently, aimed address regiocontrolled unactivated methylene NiH catalyst. benzyl can differentiated their dissociation energies steric properties, groups making up skeleton display similar electronic properties. context, exploited five-membered nickelacycle terminate NiH-mediated chain-walk isomerization, reacted furnish C(sp3)–N at γ-methylene position.This summarizes contribution activation. By exploiting inner-sphere outer-sphere pathways, successfully protocols target The mechanistic underpinning different related affiliated will discussed.

Language: Английский

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Electrochemical oxidative difunctionalization of diazo compounds with two different nucleophiles

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: March 17, 2023

With the fast development of synthetic chemistry, introduction functional group into organic molecules has attracted increasing attention. In these reactions, difunctionalization unsaturated bonds, traditionally with one nucleophile and electrophile, is a powerful strategy for chemical synthesis. this work, we develop different path electrochemical oxidative diazo compounds two nucleophiles. Under metal-free external oxidant-free conditions, series structurally diverse heteroatom-containing hardly synthesized by traditional methods (such as high-value alkoxy-substituted phenylthioacetates, α-thio, α-amino acid derivatives well α-amino, β-amino derivatives) are obtained in synthetically useful yields. addition, procedure exhibits mild reaction excellent functional-group tolerance good efficiency on large-scale Importantly, protocol also amenable to key intermediate bioactive simple practical process.

Language: Английский

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Advances in the Synthesis and Applications of N-Heterocyclic Carbene Metal Complexes with a Focus on the Weak Base Route

Organometallics, Journal Year: 2023, Volume and Issue: 42(19), P. 2692 - 2730

Published: Sept. 21, 2023

N-heterocyclic carbene (NHC) ligands have evolved from being simple lab curiosities to tertiary phosphine mimics finally take center stage as unique supporting in organometallic chemistry, homogeneous catalysis, and more recently medicinal chemistry materials science applications. Some of these aspects are presented here a perspective researchers that been fascinated by the area for quite some time.

Language: Английский

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Running Wild through Dirhodium Tetracarboxylate-Catalyzed Combined CH(C)-Functionalization/Cope Rearrangement Landscapes: Does Post-Transition-State Dynamic Mismatching Influence Product Distributions?

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(10), P. 7039 - 7051

Published: Feb. 28, 2024

A special type of C–H functionalization can be achieved through insertion combined with Cope rearrangement (CHCR) in the presence dirhodium catalysts. This reaction was studied using density functional theory and ab initio molecular dynamics simulations, results which pointed to dynamic origins low yields observed some experiments. These studies not only reveal intimate details complex network underpinning CHCR reactions but also further cement generality importance nonstatistical effects controlling Rh2L4-promoted reactions.

Language: Английский

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Transition‐Metal‐Catalyzed C−H Bond Functionalization of Arenes/Heteroarenes via Tandem C−H Activation and Subsequent Carbene Migratory Insertion Strategy

The Chemical Record, Journal Year: 2021, Volume and Issue: 21(12), P. 4088 - 4122

Published: Oct. 14, 2021

Abstract The past decade has witnessed tremendous developments in transition‐metal‐catalyzed C−H bond activation and subsequent carbene migratory insertion reactions, thus assisting the construction of diverse arene/heteroarene scaffolds. Various transition‐metal catalysts serve this purpose provide efficient pathways for an easy access to substituted heterocycles. A brief introduction metal‐carbenes been provided along with key mechanistic underlying coupling reactions. review is a concise knowledge about directing group‐assisted varied arenes/heteroarenes acceptor‐acceptor/donor‐acceptor diazo compounds. also highlights synthesis various carbocycles fused heterocycles through pathways, via C−C, C−N C−O forming mechanism usually involves process, followed by leading coupling.

Language: Английский

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State-of-the-Art Advances in Enantioselective Transition-Metal-Mediated Reactions of Silacyclobutanes

Synthesis, Journal Year: 2022, Volume and Issue: 54(24), P. 5400 - 5408

Published: Aug. 23, 2022

Abstract Studies on the enantioselective transformation of silacyclobutanes (SCBs) have become an emerging topic in recent decade, due to feature high ring strain, and manageable Si–C bond cleavage formation. This short review summarizes remarkable achievements asymmetric transition-metal-mediated reaction benzosilacyclobutanes, resulting carbon- or silicon-stereogenic organosilanes with functional substituents. 1 Introduction2 Asymmetric Transition-Metal-Catalyzed Ring Expansion Reaction3 Ring-Opening Reaction4 Conclusion Outlook

Language: Английский

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Deoxygenative Cross‐Coupling of Aromatic Amides with Polyfluoroarenes

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(11)

Published: Jan. 11, 2022

Abstract Considering the ubiquitous nature and ready synthesis of amides, great significance organofluorine‐containing species, cross‐coupling amides polyfluoroarenes, leading to new carbon–carbon bond‐forming methodologies, would find useful applications in synthesis, late‐stage functionalization, rapid generation molecular diversity. Herein, we present a novel α‐polyfluoroaryl amines via Sm/SmI 2 ‐mediated deoxygenative aromatic with polyfluoroarenes through direct C−H functionalization. The structural functional diversity these readily available precursors provides versatile flexible strategy for streamlined amines. Combining experimental theoretical studies, plausible mechanism α‐aminocarbene‐mediated insertion has been revealed, which may stimulate future work development methods amine synthesis.

Language: Английский

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