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

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(6), С. 3786 - 3794

Опубликована: Фев. 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.

Язык: Английский

---

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

Chemical Society Reviews, Год журнала: 2023, Номер 53(2), С. 764 - 792

Опубликована: Дек. 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.

Язык: Английский

---

Metallomimetic C–F Activation Catalysis by Simple Phosphines

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(3), С. 2005 - 2014

Опубликована: Янв. 11, 2024

Delivering metallomimetic reactivity from simple p-block compounds is highly desirable in the search to replace expensive, scarce precious metals by cheap and abundant elements catalysis. This contribution demonstrates that catalysis, involving facile redox cycling between P(III) P(V) oxidation states, possible using only simple, cheap, readily available trialkylphosphines without need enforce unusual geometries at phosphorus or use external oxidizing/reducing agents. Hydrodefluorination aminodefluorination of a range fluoroarenes was realized with good very yields under mild conditions. Experimental computational mechanistic studies show phosphines undergo oxidative addition fluoroaromatic substrate via Meisenheimer-like transition state form fluorophosphorane. undergoes pseudotransmetalation step silane, initial fluoride transfer P Si, give experimentally observed phosphonium ions. Hydride hydridosilicate counterion then leads hydridophosphorane, which reductive elimination product reform phosphine catalyst. behavior analogous many classical transition-metal-catalyzed reactions so rare example both functional mechanistically catalysis main-group element system. Crucially, reagents used are commercially, easy handle, making these realistic prospect wide academic industrial settings.

Язык: Английский

---

Dual Reactivity of a Geometrically Constrained Phosphenium Cation

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(36)

Опубликована: Июль 13, 2022

A geometrically constrained phosphenium cation in bis(pyrrolyl)pyridine based NNN pincer type ligand (1

Язык: Английский

---

Planar bismuth triamides: a tunable platform for main group Lewis acidity and polymerization catalysis

Chemical Science, Год журнала: 2023, Номер 14(17), С. 4549 - 4563

Опубликована: Янв. 1, 2023

Geometric deformation in main group compounds can be used to elicit unique properties including strong Lewis acidity. Here we report on a family of planar bismuth(iii) complexes (cf. typically pyramidal structure for such compounds), which show geometric acidity that further tuned by varying the steric and electronic features triamide ligand employed. The structural dynamism bismuth was probed both solid solution phase, revealing at least three distinct modes intermolecular association. A modified Gutmann-Beckett method assess their electrophilicity employing trimethylphosphine sulfide addition triethylphosphine oxide as probes, providing insights into preference binding hard or soft substrates. Experimental studies were complemented computational assessment affinities dissection latter intrinsic bond strength energy components. results comparable triarylboranes, with added ability bind two bases simultaneously, reduced discrimination against We also study catalytic efficacy these ring opening polymerization cyclic esters ε-caprolactone rac-lactide. polymers obtained excellent dispersity values high molecular weights low catalyst loadings used. retain performance under industrially relevant conditions, suggesting they may useful less toxic alternatives tin catalysts production medical grade materials. Collectively, establish not only novel neutral platform acidity, but potentially valuable one catalysis.

Язык: Английский

---

Hydrogen splitting at a single phosphorus centre and its use for hydrogenation

Nature Chemistry, Год журнала: 2024, Номер 16(8), С. 1261 - 1266

Опубликована: Июнь 27, 2024

Язык: Английский

---

Reactivity of a Strictly T‐Shaped Phosphine Ligated by an Acridane Derived NNN Pincer Ligand

Chemistry - A European Journal, Год журнала: 2023, Номер 29(39)

Опубликована: Апрель 12, 2023

Abstract The steric tuning of a tridentate acridane‐derived NNN pincer ligand allows for the isolation strictly T‐shaped phosphine that exhibits ambiphilic reactivity. Well‐defined phosphorus‐centered reactivity towards nucleophiles and electrophiles is reported, contrasting with prior reports on this class compounds. Reactions oxidants are also described. latter result in two‐electron oxidation phosphorus atom from +III to +V accompanied by strong geometric distortion ligand. By contrast, cooperative activation E−H (HCl, HBcat, HOMe) bonds proceeds retention redox state. When using H 2 O as substrate, reaction results full disassembly its constituent atoms, highlighting potential platform small molecule reactions.

Язык: Английский

---

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, Год журнала: 2023, Номер 145(32), С. 17746 - 17754

Опубликована: Авг. 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.

Язык: Английский

---

Molecular-strain induced phosphinidene reactivity of a phosphanorcaradiene

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Май 29, 2024

Abstract Phosphanorcaradienes are an appealing class of phosphorus compounds that can serve as synthons transient phosphinidenes. However, the synthesis such species is a formidable task owing to their intrinsic high reactivity. Herein we report straightforward synthesis, characterization and reactivity studies phosphanorcaradiene, in which one benzene rings flanking fluorenyl substituents intramolecularly dearomatized through attachment atom. It facilely obtained by reduction phosphorus(III) dichloride precursor with potassium graphite. Despite being thermally robust, it acts synthetic equivalent phosphinidene. reacts trimethylphosphine isonitrile yield phosphanylidene-phosphorane 1-phospha-3-azaallene, respectively. When treated two molar equivalents azide, iminophosphane bis(imino)phosphane isolated, Moreover, capable activating ethylene alkyne afford [1 + 2] cycloaddition products, well oxidative cleavage Si–H N–H bonds secondary phosphines. All reactions proceed smoothly at room temperature without presence transition metals. The driving force for these most likely ring-constraint three-membered PC 2 ring recovery aromaticity ring.

Язык: Английский

---

Reversible Oxidative Addition of Nonactivated C–H Bonds to Structurally Constrained Phosphenium Ions

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(44), С. 24184 - 24190

Опубликована: Окт. 25, 2023

A series of structurally constrained phosphenium ions based on pyridinylmethylamidophenolate scaffolds are shown to undergo P(III)/P(V) oxidative addition with C-H bonds alkynes, alkenes, and arenes. Nonactivated substrates such as benzene, toluene, deactivated chlorobenzene phosphorylated in quantitative yields. Computational spectroscopic studies suggest a low-barrier isomerization from bent T-shaped isomer that initiates phosphorus-ligand-cooperative pathway subsequent ring-chain tautomerism. Remarkably, bond activations occur reversibly, allowing for reductive elimination back P(III) at elevated temperatures or the exchange other substrates.

Язык: Английский

---