Rhodium(III)‐Catalyzed Redox‐Neutral Synthesis of Indenones from 2‐Aryl‐3‐nitrosoindoles with Alkynes

Advanced Synthesis & Catalysis, Год журнала: 2023, Номер 365(20), С. 3535 - 3539

Опубликована: Сен. 15, 2023

Abstract Herein, we developed a rhodium(III)‐catalyzed synthesis of indenones from 2‐aryl‐3‐nitrosoindoles and alkynes in redox‐neutral manner. The reaction did not require harsh conditions or any external oxidants. Mechanistic experiments DFT calculation revealed that the involved directed C−H activation, dearomative spirocyclization, N−O/C−C bond cleavage ketimine hydrolysis cascade processes.

Язык: Английский

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Weak-Chelation Assisted Cobalt-Catalyzed C–H Bond Activation: An Approach Toward Regioselective Ethynylation of N-Aryl γ-Lactam

Organic Letters, Год журнала: 2022, Номер 25(1), С. 251 - 255

Опубликована: Дек. 29, 2022

The sustainable C-H bond ethynylation of N-aryl γ-lactam has been achieved in a highly regioselective manner. In this protocol, earth-abundant cobalt(III)-catalyst was found to be effective, triggering the metalation using weakly coordinating lactam group. Herein, ortho-(sp2)-H obtained regioselectively. mechanistic studies reveal non-involvement radical pathway for conversion. However, parallel kinetic isotope experiment suggests that activation is involved rate-determining step. addition, synthetic utility ethynylated demonstrated many useful transformations.

Язык: Английский

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Copper-Catalyzed Three-Component Tandem Reaction of Alkynes, α-Diazo Esters, and TMSN₃ to Access N-Substituted 1,2,3-Triazoles

The Journal of Organic Chemistry, Год журнала: 2023, Номер 88(24), С. 17266 - 17273

Опубликована: Дек. 4, 2023

An efficient copper-catalyzed three-component tandem reaction of alkynes, α-diazo esters, and TMSN3 to construct triazoles has been developed. Through this strategy, a number diverse N-substituted 1,2,3-triazoles were conveniently obtained in moderate good yields from simple readily available starting materials using K2CO3 as the base. The mechanism Cu-catalyzed azide–alkyne cycloaddition (CuAAC) Cu-carbenoid-participated C–N coupling investigated.

Язык: Английский

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1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF₃: the case of alkyne hydration. Chemistry vs electrochemistry

Beilstein Journal of Organic Chemistry, Год журнала: 2023, Номер 19, С. 1966 - 1981

Опубликована: Дек. 28, 2023

In order to replace the expensive metal/ligand catalysts and classic toxic volatile solvents, commonly used for hydration of alkynes, reaction alkynes was studied in ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (BMIm-BF 4 ) adding boron trifluoride diethyl etherate (BF 3 ·Et 2 O) as catalyst. Different liquids were used, varying cation or anion, identify best one, terms both efficiency reduced costs. The developed method efficaciously applied different achieving desired products with good yields. results obtained using a conventional approach (i.e., BF compared those achieved electrogenerated BMIm-BF , demonstrating possibility obtaining alkyne analogous improved yields, less hazardous precursors generate reactive species situ. particular, terminal arylalkynes, electrochemical route proved be advantageous, yielding preferentially vs aldol condensation products. Importantly, ability recycle subsequent reactions successfully demonstrated.

Язык: Английский

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Switchable Regioselective C−H Activation/Annulation of Acrylamides with Alkynes for the Synthesis of 2‐Pyridones

ChemSusChem, Год журнала: 2024, Номер unknown

Опубликована: Апрель 24, 2024

A catalyst-based switchable regioselective C-H activation/annulation of acrylamides with propargyl carbonates has been developed, delivering C5 or C6 alkenyl substituted 2-pyridones. This robust protocol proceeds a broad substrate scope and good functional group tolerance under redox-neutral reaction conditions. More significantly, this is highly effective previously challenging unsymmetrical alkynes, including unbiased alkyl-alkyl perfect regioselectivity. Additionally, mechanistic studies DFT calculations were performed to shed light on the

Язык: Английский

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Ru(II)-Catalyzed Decarboxylative (4 + 2)-Annulation of Benzoic Acids and Benzamides with Propargyl Cyclic Carbonates

Organic Letters, Год журнала: 2024, Номер 26(36), С. 7590 - 7595

Опубликована: Сен. 3, 2024

Propargyl cyclic carbonates have emerged as versatile precursors in synthetic chemistry. However, their reactivity has so far been limited to transition metal-catalyzed substitution and cyclization reactions. Herein, we illustrate the successful employment of propargyl coupling partners Ru(II)-catalyzed C-H annulation benzoic acids benzamides. This approach allowed us access a broad range biologically relevant isocoumarin isoquinolinone derivatives good excellent yields, utilizing bench-stable easily accessible precursors. Preliminary mechanistic studies indicated that metalation step is both reversible rate-determining reaction pathway. Furthermore, utility developed methodology illustrated by scale-up postfunctionalization experiments.

Язык: Английский

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Carboxylate‐Directed Oxidative Annulation via C(Alkenyl)－H Activation/Double Alkyne Insertion/1,4‐Pd Migration: Synthesis of Functionalized Naphthalenes

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 1, 2024

Abstract A palladium‐catalyzed double consecutive C(alkenyl)−H activation/alkyne insertion method utilizing a free carboxylic acid as directing group in the preparation of functionalized naphthalenes is reported. The reaction mechanism involves sequence C (alkenyl)−H insertion/1,4‐palladium migration/reductive elimination steps. second alkyne occurred at phenyl ring intermediate generated from first via 1,4‐palladium migration, which an uncommon case typical C−H chemistry, providing naphthalene products. Additionally, kinetic studies and control experiments well density functional theory (DFT) are also investigated to elucidate mechanism.

Язык: Английский

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Pd-Catalyzed ortho-/meta-C-H-annulation of biphenyl amines with enynes through non-rollover cyclometallation

Organic & Biomolecular Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Янв. 1, 2024

A Pd-catalyzed, regio- and diastereoselective cascade reaction of biphenyl amines with 1,6-enynes via non-rollover cyclometallation has been described for the synthesis benzoisoindolinone derivatives.

Язык: Английский

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