Cyclopentadienone Vanadium(I) Complex: Synthesis, Red/Ox Activity, and Application to Catalytic Transfer Hydrogenation

Organometallics, Год журнала: 2023, Номер 42(10), С. 865 - 870

Опубликована: Май 3, 2023

Cyclopentadienone late transition metal complexes have exhibited various catalytic transformation and elementary reactions by transferring electrons from the to ligand, so-called metal–ligand cooperation mechanism. Herein, we report a cyclopentadienone low-valent early metal, vanadium(I), complex. The obtained complex furnished most extended C═O bond length among all of analogous CpO complexes, showing substantial degree metal-to-ligand electron transfer. red/ox activity vanadium center in V(I) was confirmed upon addition proton source yield hydroxycyclopentadienyl V(III) system applied transfer hydrogenation carbonyl compounds, indicating possible application metals cooperative organic transformations.

Язык: Английский

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A Simple Protocol for the C−N Cross‐Coupling of Aryl Chlorides with Amines Applying Ni/NHC Catalysis

ChemCatChem, Год журнала: 2023, Номер 15(13)

Опубликована: Май 17, 2023

Abstract An efficient protocol for the C−N cross‐coupling of aryl chlorides with (hetero)aryl‐ and alkyl amines under nickel catalysis has been developed. The main advantage is use a self‐activated Ni/NHC catalytic system generated in situ from readily available bench‐stable air‐tolerant precursors: NiCl 2 Py , IPr ⋅ HCl, sodium tert ‐butoxide. A mass spectrometry mechanistic study reaction revealed dynamics competitive processes active species formation degradation involving NHC reductive elimination reactions ‐butoxide base. Optimization /IPr HCl/ t BuONa ratio temperature allowed to be achieved. developed simple represents an alternative methods relying on air‐sensitive unstable Ni(cod) or expensive well‐defined precatalysts.

Язык: Английский

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Activation Mechanism of Nickel(0) N-Heterocyclic Carbene Catalysts Stabilized by Fumarate Ligands

Organometallics, Год журнала: 2022, Номер 41(22), С. 3293 - 3300

Опубликована: Авг. 25, 2022

Nickel(0) catalysts of N-heterocyclic carbenes (NHCs) that are stabilized by electron-deficient alkenes possess desirable properties air tolerance and ease handling while also retaining high catalytic activities. Since catalyst stability often comes at the expense activity, we have undertaken a detailed study activation mechanism an IMes-nickel(0) di(o-tolyl) fumarate converts stable precatalyst form into catalytically active species. Computational evaluation provided evidence against simple ligand exchange as for this catalyst, stoichiometric process covalently modifies stabilizing was identified. A computational picture developed, with predictive insights elucidate unexpected pathway operates when is thermodynamically unfavorable.

Язык: Английский

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Stereodivergent, Kinetically Controlled Isomerization of Terminal Alkenes via Nickel Catalysis

Angewandte Chemie, Год журнала: 2024, Номер 136(21)

Опубликована: Март 18, 2024

Abstract Because internal alkenes are more challenging synthetic targets than terminal alkenes, metal‐catalyzed olefin mono‐transposition (i.e., positional isomerization) approaches have emerged to afford valuable E ‐ or Z‐ from their complementary alkene feedstocks. However, the applicability of these methods has been hampered by lack generality, commercial availability precatalysts, and scalability. Here, we report a nickel‐catalyzed platform for stereodivergent / Z ‐selective synthesis at room temperature. Commercial reagents enable this one‐carbon transposition ‐internal via Ni−H‐mediated insertion/elimination mechanism. Though mechanistic regime is same in both systems, underlying pathways that lead each active catalysts distinct, with catalyst forming comproportionation an oxidative addition complex followed substrate protonation metal trialkylphosphonium salt additive. In case, ligand sterics denticity control stereochemistry prevent over‐isomerization.

Язык: Английский

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Alkylation of azoles with alkenes catalyzed by the NiCl2Py2/IMes • HCl/ButONa system

Russian Chemical Bulletin, Год журнала: 2024, Номер 73(9), С. 2680 - 2686

Опубликована: Сен. 1, 2024

Язык: Английский

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