Metallomimetic Chemistry of a Cationic, Geometrically Constrained Phosphine in the Catalytic Hydrodefluorination and Amination of Ar–F Bonds

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(6), P. 3786 - 3794

Published: Feb. 4, 2023

The synthesis, isolation, and reactivity of a cationic, geometrically constrained σ3-P compound in the hexaphenyl-carbodiphosphoranyl-based pincer-type ligand (1+) are reported. 1+ reacts with electron-poor fluoroarenes via an oxidative addition-type reaction C-F bond to PIII-center, yielding new fluorophosphorane-type species (PV). This was used catalytic hydrodefluorination Ar-F bonds PhSiH3, C-N bond-forming cross-coupling reactions between aminosilanes. Importantly, these closely mimics mode action transition metal-based catalysts.

Language: Английский

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Ligand-enforced geometric constraints and associated reactivity in p-block compounds

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 53(2), P. 764 - 792

Published: Dec. 15, 2023

This review presents a group-wise summary of ligand enforced non-VSEPR geometries in compounds the p-block elements and discusses emergent consequences for reactivity.

Language: Английский

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Calix[4]pyrrolato-germane-(thf)₂: Unlocking the Anti-van’t Hoff–Le Bel Reactivity of Germanium(IV) by Ligand Dissociation

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(32), P. 17746 - 17754

Published: Aug. 7, 2023

Anti-van't Hoff-Le Bel configured p-block element species possess intrinsically high reactivity and are thus challenging to isolate. Consequently, numerous elements in this configuration, including square-planar germanium(IV), remain unexplored. Herein, we follow a concept reach anti-van't by ligand dissociation from rigid calix[4]pyrrole germane its bis(thf) adduct. While the macrocyclic assures coordination uncomplexed form, labile thf donors provide robustness for isolation on multigram scale. Unique properties of low-lying acceptor orbital imparted germanium(IV) can be verified, e.g., isolating an elusive anionic hydrido germanate exploiting it bond activations. Aldehydes, water, alcohol, CN triple activated first time germanium-ligand cooperativity. Unexpected behaviors against fluoride ion disclose critical interferences putative redox-coupled transfer during experimental determination Lewis acidity. Overall, showcase how lability grants access uncharted chemistry line up as member emerging class structurally constrained elements.

Language: Английский

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Metal Complexes of Redox Non-Innocent Ligand N,N′-Bis(3,5-di-tertbutyl-2-hydroxy-phenyl)-1,2-phenylenediamine

Molecules, Journal Year: 2024, Volume and Issue: 29(5), P. 1088 - 1088

Published: Feb. 29, 2024

Redox non-innocent ligands react with metal precursors to form complexes where the oxidation states of ligand and thus atom cannot be easily defined. A well-known example such is bis(o-aminophenol) N,N′-bis(3,5-di-tertbutyl-2-hydroxy-phenyl)-1,2-phenylenediamine, previously developed by Wieghardt group, which has a potentially tetradentate coordination mode four distinct protonation states, whereas its electrochemical behavior allows for five states. This rich redox chemistry, as well ability coordinate various transition metals, been utilized in syntheses M2L, ML ML2 stoichiometries, sometimes supported other ligands. Different can adopt different modes. For example, fully oxidized form, two N donors are sp2-hybridized, makes planar, reduced sp3-hybridized allow formation more flexible chelate structures. In general, during complexation, but processes isolated typically occur on ligand. Combination this redox-active metals may lead interesting magnetic, electrochemical, photonic catalytic properties.

Language: Английский

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Mesomeric Tuning at Planar Bi centres: Unexpected Dimerization and Benzyl C−H Activation in [CN₂]Bi Complexes

ChemPlusChem, Journal Year: 2022, Volume and Issue: 87(11)

Published: Sept. 2, 2022

Planar bismuth(III) compounds featuring a N3 -pincer ligand environment are an unusual class of main group that exhibit Lewis acidity via 6p orbital. The ability to tune their Hammett and Coulomb effects has been demonstrated previously. Here we test the them mesomeric by replacing central nitrogen [N3 ] pincer with less π-donating carbon atom achieve [CN2 environment. This strategy boosts at metal such extent only strongly-bound dimers can be accessed in condensed phase, or, if dimerization is sterically prohibited, reductive elimination occurs give Bi(I) compounds. These results highlight fine line separating donor/acceptor redox chemistry planar bismuth centres.

Language: Английский

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Ligand‐Enabled Disproportionation of 1,2‐Diphenylhydrazine at a P^V‐Center**

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(35)

Published: June 17, 2022

We present herein the synthesis of a nearly square-pyramidal chlorophosphorane supported by tetradentate bis(amidophenolate) ligand, N,N'-bis(3,5-di-tert-butyl-2-phenoxy)-1,2-phenylenediamide. After chloride abstraction resulting phosphonium cation efficiently promotes disproportionation 1,2-diphenylhydrazine to aniline and azobenzene. Mechanistic studies, spectroscopic analyses theoretical calculations suggest that this unprecedented reactivity mode for P

Language: Английский

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Are Ar₃SbCl₂ Species Lewis Acidic? Exploration of the Concept and Pnictogen Bond Catalysis Using a Geometrically Constrained Example

Organometallics, Journal Year: 2023, Volume and Issue: 42(3), P. 240 - 245

Published: Jan. 30, 2023

As part of our investigations into the Lewis acidic behavior antimony derivatives, we have decided to study properties 5-phenyl-5,5-dichloro-λ5-dibenzostibole (1), a dichlorostiborane with an atom confined five-membered heterocycle. Our work shows that resulting geometrical constraints elevate acidity atom, as confirmed by crystal structure 1-THF and solution interaction 1 Ph3PO. The enhanced 1, which exceed those simple dichlorostiboranes such Ph3SbCl2, also become manifest in pnictogen bonding catalysis experiments involving reductions imines Hantzsch ester. influence chemistry this compound is supported computational activation strain analysis well energy decomposition model Me3PO adduct.

Language: Английский

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Cooperation between p‐Block Elements and Redox‐Active Ligands: Stoichiometric and Catalytic Transformations

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 30(9)

Published: Nov. 14, 2023

The relevance acquired by redox-active ligands in modern catalysis stems from their facile delivery and acceptance of electrons, either to the metal they coordinate to, or directly an incoming substrate that also binds central metal. Doing that, generate coordinated radicals provide access more than one spin state during catalytic cycle. As a consequence, new reaction barriers are reduced when compared similar processes restricted single surface. principles govern this genuine approach catalyst design well-established, implementation has allowed development synthetically useful transformations; however, extension concept species which p-block elements take role atoms remains largely underdeveloped. Through discussion key achievements recent progress, Concept Article highlights original designing (organo)catalysts, discloses progress achieved, reveals many shortcomings still exist field.

Language: Английский

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Three‐Component Synthesis of Dioxaphosphorane‐Fused Diphosphacycles Exhibiting Unique Dynamic Fluorescence “On/Off” Properties

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 62(6)

Published: Dec. 16, 2022

Abstract Rigidly planar polycyclic phosphacycles featuring an internal dioxaphosphorane are promising photofunctional materials. However, the lack of efficient synthetic methods resulted in limited structural diversities which significantly hampered extensive study. Herein, we report a straightforward three‐component synthesis novel dioxaphosphorane‐fused diphosphacycles with distinctive photophysical properties. Control experiments and theory calculations were performed to account for plausible reaction mechanism. We also systematically investigated structure‐property relationships these unprecedented platforms by combining (X‐ray analysis, optical redox properties) theoretical computations. Based on their unique structure properties, fluorescent switch pH sensing was revealed dynamic ring‐opening/ring‐closing process.

Language: Английский

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Bis(amidophenolato)phosphonium: Si−H Hydride Abstraction and Phosphorus‐Ligand Cooperative Activation of C−C Multiple Bonds

Chemistry - A European Journal, Journal Year: 2022, Volume and Issue: 29(8)

Published: Nov. 11, 2022

The first bis(amidophenolato)phosphonium salts are prepared and fully characterized. perfluorinated derivative represents the strongest monocationic phosphorus Lewis acid on fluoride hydride ion affinity scale isolable to date. This enables new reactions, such as abstraction from Et3 SiH, phosphaalkoxylation of an alkyne or a catalyzed intramolecular hydroarylation. All properties reactions scrutinized by theory experiment. Substantial σ- π-acidity provides required for substrate activation, while phosphorus-ligand cooperativity substantially enriches reactivity portfolio phosphonium ions.

Language: Английский

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