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

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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

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Combining geometric constraint and redox non-innocence within an ambiphilic PBiP pincer ligand

Chemical Science, Год журнала: 2024, Номер 15(16), С. 6036 - 6043

Опубликована: Янв. 1, 2024

The first pincer ligand featuring a strictly T-shaped pnictogen donor moiety was synthesised. PBiP ligand's redox activity facilitates unprecedented ambiphilic bonding of the Bi centre with transition metals through Bi(6p) orbital.

Язык: Английский

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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

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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

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Highly selective, reversible water activation by P,N-cooperativity in pyridyl-functionalized phosphinines

Chemical Science, Год журнала: 2024, Номер 15(15), С. 5496 - 5506

Опубликована: Янв. 1, 2024

Tetrapyridyl-functionalized phosphinines were prepared and structurally characterized. The donor-functionalized aromatic phosphorus heterocycles react highly selectively even reversibly with water. Calculations reveal P,N-cooperativity for this process, the flanking pyridyl groups serving to kinetically enhance formal oxidative addition process of H2O low-coordinate atom via H-bonding. Subsequent tautomerization forms 1,2-dihydrophosphinine derivatives, which can be quantitatively converted back phosphinine by applying vacuum, at room temperature. This repeated numerous times, without any sign decomposition phosphinine. In presence CuI·SMe2, dimeric species type ([Cu2I2(phosphinine)]2) are formed, in each shows less common μ2-bridging 2e--lone-pair-donation two Cu(i)-centres. Our results demonstrate that fully unsaturated heterocycles, containing reactive P[double bond, length as m-dash]C double bonds, interesting candidates activation E-H while aromaticity such compounds plays an appreciable role reversibility reaction, supported NICS calculations.

Язык: Английский

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Why Are Some Pnictogen(III) Pincer Complexes Planar and Others Pyramidal?

Chemistry - A European Journal, Год журнала: 2024, Номер 30(57)

Опубликована: Июль 30, 2024

Geometrically-constrained pnictogen pincer complexes have emerged in recent years as platforms for unique stoichiometric and catalytic chemical transformations. These feature dynamic conformations ranging from fully planar at the centre to distorted-pyramidal geometries, well variation between phases. Although valued reactivity of is ascribed their there no unified model explain observed conformational outcomes across different ligands centres. Here we propose such a through computational analysis more than 1300 structures 64 (16 4 heavy pnictogens), explaining experimental observations making new predictions. By looking signatures bond stability (bond lengths, Wiberg indices) delocalization (NPA charges, Hirshfeld charges), our framework posits pnictogen-based σ-bonding effect that favours pyramidalization exists competition with ligand-based π-bonding planarity. Variations structure function identity, ligand tethering, electronics, aromaticity can be reconciled reference balance these two opposing forces. Careful consideration σ/π-bonding effects may aid rational design future predictable geometries reactivities.

Язык: Английский

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Flash Communication: Ligand Centered Cooperative O–H Bond Splitting by a Mo(CO)₅(phosphine) Complex

Organometallics, Год журнала: 2025, Номер unknown

Опубликована: Янв. 22, 2025

The synthesis and reactivity of a molybdenum carbonyl complex ligated by geometrically constrained phosphorus trisamide are reported. Reaction with potassium tert-butoxide or methanol triggers ligand-centered substrate activation, leading to planarization the phosphine donor ligand. P–O bond formation, decarbonylation, insertion center into ligand P–N result in formation tetracarbonyl complexes rigid N,P-chelate ligands.

Язык: Английский

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Meta-Xylene-Based Diamines with Protected Benzyl Sites: Potential NCN Pincer Ligands with Tunable Steric Profiles

Molecules, Год журнала: 2025, Номер 30(6), С. 1331 - 1331

Опубликована: Март 16, 2025

Bulky NCN aryl-diamides featuring methyl groups in the benzyl positions were synthesized with aim of creating a new class meta-xylene-based trianionic pincer ligands where common decomposition pathway metal complexes via C-H activation is prevented. Sterically demanding substituents on furthermore provide steric protection centre and can help prevent dimerization complexes. While double deprotonation formation dilithium salt was straightforward, difficulties encountered when attempting to deprotonate ipso-CH proton central aryl ring yield ligands. This stands contrast related without benzylic positions. Experimental theoretical investigations led conclusion that challenges third are likely caused by an interplay increased electron density at nitrogen atoms hindrance. Both effects originate introduction positions, which make targeted less accessible. These results further insight into impact both electronic properties ligands, may find utility coordination chemistry applications metalation be achieved direct rather than requiring triple deprotonation.

Язык: Английский

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Direct O₂ Activation by Ligand-Constrained Pnictogen Complexes: Contrasting Mechanisms and OAT Reactivity across the P, Sb, and Bi Triad

JACS Au, Год журнала: 2025, Номер unknown

Опубликована: Июнь 3, 2025

Язык: Английский

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