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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Metallomimetic C–F Activation Catalysis by Simple Phosphines

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(3), P. 2005 - 2014

Published: Jan. 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.

Language: Английский

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

Chemical Science, Journal Year: 2024, Volume and Issue: 15(16), P. 6036 - 6043

Published: Jan. 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.

Language: Английский

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

Nature Chemistry, Journal Year: 2024, Volume and Issue: 16(8), P. 1261 - 1266

Published: June 27, 2024

Language: Английский

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

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(39)

Published: April 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.

Language: Английский

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

Chemical Science, Journal Year: 2024, Volume and Issue: 15(15), P. 5496 - 5506

Published: Jan. 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.

Language: Английский

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

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(57)

Published: July 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.

Language: Английский

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

Organometallics, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 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.

Language: Английский

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

Molecules, Journal Year: 2025, Volume and Issue: 30(6), P. 1331 - 1331

Published: March 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.

Language: Английский

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Ligand Centered Reactivity of a Transition Metal Bound Geometrically Constrained Phosphine

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(26)

Published: March 4, 2024

The electronic properties, coordination chemistry and reactivity of metal complexes a planar (C

Language: Английский

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