Ni‐SPO‐Al Catalyzed Stereoselective C–H Alkenylation of Quinazolinones with Alkynes to Prepare trans‐Isomers

European Journal of Organic Chemistry, Год журнала: 2025, Номер 28(5)

Опубликована: Янв. 4, 2025

Abstract A stereoselective Ni−Al bimetal‐catalyzed C−H alkenylation of quinazolinones with alkynes has been successfully developed. Good selectivity Z‐type quinazolinone products was obtained using readily available substrates, which exhibits a trans‐configuration opposite to the conventional alkynylation reactions and improves diversity compounds. In addition, reaction process further explored through KIE other control experiments, possible mechanism proposed.

Язык: Английский

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New reactivity of late 3d transition metal complexes in catalytic reactions of alkynes

Chemical Society Reviews, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

This review summarizes seven types of new reactivities found in late 3d metal complexes and catalytic examples recent years.

Язык: Английский

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Unusual Regioselective C–H Difluoroalkylation of Heteroarenes under Photoredox Catalysis

Organic Letters, Год журнала: 2024, Номер 26(24), С. 5098 - 5104

Опубликована: Июнь 7, 2024

We disclose a new general strategy for the site-selective difluoroalkylation of nonprefunctionalized heteroarenes, such as quinoxaline at C-8 position, and benzothiadiazole, benzoxadiazole, benzothiazole C-4 position via consecutive organophotoredox-catalyzed radical–radical cross-coupling base-assisted hydrogen abstraction reactions. The current methodology represents direct difluoroalkylative to allow broad functional group tolerance wide substrate scope in good excellent yields. Careful experimental investigations detailed DFT calculations revealed exact site-selectivity heteroarenes possible mechanistic pathway.

Язык: Английский

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Aerobic oxidation of alkyl aromatics to ketones catalyzed by biomimetic copper complex and N-hydroxyphthalimide (NHPI) under mild conditions

Molecular Catalysis, Год журнала: 2023, Номер 552, С. 113673 - 113673

Опубликована: Ноя. 16, 2023

Язык: Английский

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DFT Study on Mechanism of Ni–Al Bimetallic-Catalyzed C–H Cyclization to Construct Tricyclic Imidazoles: Roles of NHC Ligand and AlMe₃

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(3), С. 1505 - 1514

Опубликована: Янв. 13, 2024

The mechanism of the Ni–Al bimetallic-catalyzed C–H cyclization to construct tricyclic imidazoles is investigated using density functional theory calculations. calculation result shows that reaction involves sequential steps substrate coordination, ligand-to-ligand hydrogen transfer (LLHT), and C–C reductive elimination produce final product imidazole. LLHT step calculated be rate-determining step. oxidative addition benzimidazole bond Ni center insertion alkene into Ni–H occur concertedly in effects N-heterocyclic carbene (NHC) ligands AlMe3 on reactivity regioselectivity were also analyzed. These results shed light some ambiguous suggestions from experiments.

Язык: Английский

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Tailored SPO-Pd-NPs catalysts for selective synthesis of tri-conjugated enynes by alkynylation of allenes

Journal of Catalysis, Год журнала: 2024, Номер 432, С. 115438 - 115438

Опубликована: Март 13, 2024

Язык: Английский

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C–H Activation of Pyridines by Boryl Pincer Complexes: Elucidation of Boryl-Directed C–H Oxidative Addition to Ir and Discovery of Transition Metal-Assisted Reductive Elimination from Boron at Rh

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(45), С. 31281 - 31294

Опубликована: Окт. 30, 2024

Experimental and theoretical techniques were used to investigate the mechanism of pyridine C–H activation by diarylboryl/bis(phosphine) PBP pincer complexes Ir. The critical intermediate (PBP)IrCO (4) contains a three-coordinate, Ir-bound boron that retains Lewis acidity in perpendicular direction. Coordination this center 4 leads fast insertion Ir into 2-CH bond pyridine, providing different topology direction than conventional directed where both directing group coordination happen at same metal center. Beyond sequence, system possesses significant complexity terms possible isomers pathways, which have been thoroughly explored. Kinetic thermodynamic preferences for differently substituted pyridines also investigated. In experimental work, key is accessed via elimination benzene from phenyl/hydride containing precursor (PBPhP)IrHCO (3). Density functional theory (DFT) investigations loss 3 revealed possibility genuinely new type mechanism, whereby Ph–H made concerted process best described as reductive boron, assisted transition (TMARE). For Ir, pathway was predicted be competitive with more pathways involving but still higher energy barrier. However, Rh analog 3-Rh, TMARE calculated preferred prediction experimentally corroborated through study reaction rates kinetic isotope effect.

Язык: Английский

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A Catalytic Collaboration: Pairing Transition Metals and Lewis Acids for Applications in Organic Synthesis

Dalton Transactions, Год журнала: 2024, Номер 53(32), С. 13298 - 13307

Опубликована: Янв. 1, 2024

The use of metal catalysts to accelerate an organic transformation has proven indispensable for access structural motifs having applications across medicinal, polymer, materials chemistry, and more. Most catalytic approaches have cast transition metals in the "leading role"; these players mediate important reactions such as C-C cross coupling hydrogenation unsaturated bonds. These may require collaboration, featuring Lewis acidic or basic additives promote a desired reaction outcome. acids can serve by way substrate stabilization and/or activation, such, are valuable optimizing transformations. A burgeoning area chemical research which unifies concepts thus sought develop complexes ambiphilic (containing unit) ligands. This approach takes advantage metal-ligand cooperativity increase efficiency given transformation, leveraging intramolecular interactions between adjacent secondary ligand site. While this shown significant potential facilitate challenging transformations, there remains unexplored depth creativity future advancement.

Язык: Английский

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Catalytic Addition of C–H Bonds Across C–C π-Bonds

Elsevier eBooks, Год журнала: 2023, Номер unknown

Опубликована: Янв. 1, 2023

Язык: Английский

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