N-heterocyclic carbene Pd(II) complex supported on Fe3O4@SiO2: Highly active, reusable and magnetically separable catalyst for Suzuki-Miyaura cross-coupling reactions in aqueous media

Journal of Organometallic Chemistry, Journal Year: 2021, Volume and Issue: 943, P. 121823 - 121823

Published: April 16, 2021

Language: Английский

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N-Heterocyclic Carbene Complexes of Nickel(II) from Caffeine and Theophylline: Sustainable Alternative to Imidazol-2-ylidenes

Organometallics, Journal Year: 2022, Volume and Issue: 41(14), P. 1806 - 1815

Published: April 5, 2022

Xanthines, such as caffeine and theophylline, are abundant natural products that often present in foods. Leveraging renewable benign resources for ligand design organometallic chemistry catalysis is one of the major missions green sustainable chemistry. In this Special Issue on Sustainable Organometallic Chemistry, we report first nickel–N-heterocyclic carbene complexes derived from Xanthines. Well-defined air- moisture-stable, half-sandwich, cyclopentadienyl [CpNi(NHC)I] nickel–NHC prepared theophylline. The model complex has been characterized by X-ray crystallography. evaluation steric, electron-donating, π-accepting properties presented. High activity Suzuki–Miyaura cross-coupling demonstrated. data show carbenes both earth 3d transition metal represent a alternative to classical imidazol-2-ylidenes.

Language: Английский

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ItOct (ItOctyl) – pushing the limits of ItBu: highly hindered electron-rich N-aliphatic N-heterocyclic carbenes

Chemical Science, Journal Year: 2023, Volume and Issue: 14(19), P. 5141 - 5147

Published: Jan. 1, 2023

ItBu (ItBu = 1,3-di-tert-butylimidazol-2-ylidene) represents the most important and versatile N-alkyl N-heterocyclic carbene available in organic synthesis catalysis. Herein, we report synthesis, structural characterization catalytic activity of ItOct (ItOctyl), C2-symmetric, higher homologues ItBu. The new ligand class, including saturated imidazolin-2-ylidene analogues has been commercialized collaboration with MilliporeSigma: ItOct, 929 298; SItOct, 492 to enable broad access academic industrial researchers within field inorganic synthesis. We demonstrate that replacement t-Bu side chain t-Oct results highest steric volume carbenes reported date, while retaining electronic properties inherent N-aliphatic ligands, such as extremely strong σ-donation crucial reactivity carbenes. An efficient large-scale imidazolium imidazolinium SItOct precursors is presented. Coordination chemistry Au(i), Cu(i), Ag(i) Pd(ii) well beneficial effects on catalysis using complexes are described. Considering tremendous importance catalysis, metal stabilization, anticipate class ligands will find wide application pushing boundaries existing approaches

Language: Английский

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Pt^II−N‐Heterocyclic Carbene Complexes in Solvent‐Free Alkene Hydrosilylation

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(40)

Published: May 17, 2023

Herein, we report the catalytic activity of a series platinum(II) pre-catalysts, bearing N-heterocyclic carbene (NHC) ligands, in alkene hydrosilylation reaction. Their structural and electronic properties are fully investigated using X-ray diffraction analysis nuclear magnetic resonance spectroscopy (NMR). Next, our study presents structure-activity relationship within this group pre-catalysts gives mechanistic insights into catalyst activation step. An exceptional performance one complexes is observed, reaching turnover number (TON) 970 000 frequency (TOF) 40 417 h-1 at 1 ppm loading. Finally, an attractive solvent-free open-to-air protocol, featuring efficient platinum removal (reduction residual Pt from 582 to 5.8 ppm), disclosed.

Language: Английский

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Palladium(II) complexes bearing thioether-NHC ligand: Synthesis, characterization, and their application in Suzuki-Miyaura coupling

Inorganica Chimica Acta, Journal Year: 2024, Volume and Issue: 563, P. 121910 - 121910

Published: Jan. 3, 2024

Language: Английский

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Ln(ii) amido complexes coordinated by ring-expanded N-heterocyclic carbenes – promising catalysts for olefin hydrophosphination

Chemical Communications, Journal Year: 2020, Volume and Issue: 56(85), P. 12913 - 12916

Published: Jan. 1, 2020

First Ln(ii) ring-expanded NHC complexes (er-NHC)Ln[N(SiMe3)2]2 (Ln = Sm, Yb) are synthesized and proved to be highly efficient pre-catalysts for the intermolecular hydrophosphination of such indolent substrates as 1-alkenes, cyclohexene norbornene.

Language: Английский

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Probing Electronic Properties of Triazolylidenes through Mesoionic Selones, Triazolium Salts, and Ir-Carbonyl-Triazolylidene Complexes

Organometallics, Journal Year: 2020, Volume and Issue: 39(24), P. 4557 - 4564

Published: Nov. 23, 2020

Understanding and quantifying the electronic properties of ligands is important both from a fundamental point view also for their applications in various branches chemistry. In this contribution, we present comparative study on donor/acceptor 10 different triazolylidene-type mesoionic carbene (MICs), with aim investigating deciphering effects substituents such MIC ligands. Data 77Se NMR chemical shifts triazoline selones, 1JC-H coupling constants corresponding triazolium salts, Tolman parameters (TEP) Ir-CO complexes are compared contrasted. The data collected work show that spread TEP relatively narrow to be able significantly differentiate between donor MICs. selones other hand broad spread, it principle well-suited understand π-accepting MICs as function substituents. However, method can have complications which discussed work. DFT calculations presented light shifts. Additionally, first example AuI complex class whose utility has remained underexplored transition metal

Language: Английский

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New class of RSO₂-NHC ligands and Pd/RSO₂-NHC complexes with tailored electronic properties and high performance in catalytic C–C and C–N bonds formation

Dalton Transactions, Journal Year: 2023, Volume and Issue: 52(34), P. 12067 - 12086

Published: Jan. 1, 2023

Imidazolium salts have found ubiquitous applications as N-heterocyclic carbene precursors and metal nanoparticle stabilizers in catalysis metallodrug research. Substituents directly attached to the imidazole ring can a significant influence on electronic, steric, other properties of NHC-proligands well their complexes. In present study, for first time, new type Pd/NHC complex with RSO2 group imidazol-2-ylidene ligand core was designed synthesized. The electronic structural features ligands were evaluated by means experimental computational methods. Interestingly, introduction 4-aryl(alkyl)sulfonyl only slightly decreased electron donation, but it significantly increased π-acceptance enhanced buried volume (%Vbur) imidazol-2-ylidenes. New complexes obtained through selective C(2)H-palladation some synthesized 4-RSO2-functionalized imidazolium under mild conditions. Several demonstrated good activity model cross-coupling reactions, outperforming similar non-substituted NHC ligands.

Language: Английский

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Self‐Assembled Monolayers of N‐Heterocyclic Olefins on Au(111)

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(46)

Published: Sept. 25, 2023

Self-assembled monolayers (SAMs) of N-heterocyclic olefins (NHOs) have been prepared on Au(111) and their thermal stability, adsorption geometry, molecular order were characterized by X-ray photoelectron spectroscopy, polarized absorption scanning tunneling microscopy (STM), density functional theory (DFT) calculations. The strong σ-bond character NHO anchoring to Au induced high geometrical flexibility that enabled a flat-lying geometry via coordination gold adatom. was utilized further increase the surface interaction monolayer backbone functionalization with methyl groups stability large impact work-function values, which outperformed carbenes. STM measurements, supported DFT modeling, identified NHOs self-assembled in dimers, trimers, tetramers constructed two, three, four complexes NHO-Au-adatom. This self-assembly pattern correlated NHO-Au interactions steric hindrance between adsorbates, demonstrating crucial influence carbon-metal properties.

Language: Английский

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Bulky N-heterocyclic carbene Cu(I) complex as a catalyst for the synthesis of N-arylazoles under ambient conditions

Tetrahedron, Journal Year: 2025, Volume and Issue: 172, P. 134449 - 134449

Published: Jan. 5, 2025

Language: Английский

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