Developments in the Coordination Chemistry of Phosphinines

Simple Synthesis of Functionalized 2-Phosphanaphthalenes

A simple synthesis of sodium 2-phosphanaphthalene-3-olate (1) based on the extrusion of N₂ from phthalazine using Na[OCP] is reported. This heterocycle can be readily functionalized at the negatively charged oxygen center using a variety of electrophilic substrates. The coordination chemistry of both 1 and its neutral derivatives was explored, revealing their facile use as P-donor ligands for late-transition-metal complexes.

1,1'-Binaphthyl-substituted diphosphene: synthesis, structures, and chiral optical properties

1,1'-Binaphthyl-substituted diphosphene 1 possessing a P[double bond, length as m-dash]P double bond and an axially chiral 1,1'-binaphthyl group was synthesized and fully characterized. Diphosphene 1 was prepared as an optically active form and thus is the first example of a chiral diphosphene. The CD spectra of 1 showed apparent circular dichroism in the longer wavelength region, caused by the P[double bond, length as m-dash]P moiety.

1,4-Additions of tricyclic 1,4-diphosphinines - a novel system to study σ-bond activation and π-π dispersion interactions

The dienic nature of the aromatic π-system in 1,4-diphosphinines remains largely unexplored to this day due to a lack of facile and efficient synthetic protocols. Recently reported stable, tricyclic 1,4-diphosphinines were used to explore the thermal reactivity of the π-system towards an array of dienophiles in [4π+2π]- and, for the first time, in [4π+2σ]-type cycloaddition reactions.

Substituent effects in pyridyl-functionalized pyrylium salts, pyridines and λ3,σ2-phosphinines: a fundamental and systematic study

A series of pyridyl-functionalized O⁺–, N–, and P– containing heterocycles have been prepared and investigated for substituent effects.

A substituent-tolerant synthetic approach to N/P-“loaded” heteroarenes

Tetrazines react with OCP⁻¹ through a reverse electron demand Diels–Alder process to produce 3,6-disubstituted-1,2,4-diazaphosphinin-5-olates.

Highlights on π-systems based on six-membered phosphorus heterocycles

Herein, we highlight relevant π-systems based on six-membered phosphorus heterocycles as well as their potential in bio- and optoelectronic applications.

Two isomers of a bis(diphenylphosphino)phosphinine, and the synthesis and reactivity of Ru arene/Cp* phosphinophosphinine complexes

Two isomers of a bis(diphenylphosphino)phosphinine have been synthesised, and the Ru coordination chemistry of a 2-phosphinophosphinine extended to include reactions of H₂O across a PC double bond.

Expanding the chemistry of ring-fused 1,4-diphosphinines by stable mono anion formation

Synthesis of a novel tricyclic 1,4-diphosphinine I and, subsequently, of a stable anionic 1,4-diphosphinine II is reported; while II can be used as precursor for 1,4-disubstitution products, its oxidation leads to the formation of the P–P coupling product III.

Small bite-angle 2-phosphinophosphinine ligands enable rhodium-catalysed hydroboration of carbonyls

2-Phosphinophosphinine ligands generate Rh catalysts for the hydroboration of ketones and imines in contrast to standard phosphine ligands.

A ruthenium(ii) bis(phosphinophosphinine) complex as a precatalyst for transfer-hydrogenation and hydrogen-borrowing reactions

A Ru(ii) complex with 2-phosphinophosphinine ligands activated with KO^tBu catalyses the room temperature transfer hydrogenation of acetophenone and the hydrogen-borrowing reaction of MeOH/EtOH to the advanced biofuel isobutanol.

Reaction of a 2,4,6-triphenylphosphinine ferrate anion with electrophiles: a new route to phosphacyclohexadienyl complexes

Electrophilic attack at π-coordinated 2,4,6-triphenylphosphinine afforded a range of novel complexes with substituted η⁵-phosphacyclohexadienyl ligands.

[Re(CO)3Cl(C5H4ClP)2] and [Re(CO)2Cl(C5H4ClP)3]: synthesis and characterization of two novel rhenium(i) phosphinine complexes

Two novel rhenium(i) phosphinine complexes [Re(CO)₃Cl(η¹-C₅H₄ClP)₂] (1) and [Re(CO)₂Cl(η¹-C₅H₄ClP)₃] (2) were synthesized and the molecular structure of both was determined by single crystal X-ray diffraction.

π-Excess aromatic σ²-P ligands: synthesis and structure of an unprecedented μ²-P-1,3-benzazaphosphole bridged tetranuclear copper(I) acetate complex

The -P=CH-NR-heterocycle 1-neopentyl-1,3-benzazaphosphole (npBAP) reacts in THF with copper(I) acetate via labile soluble complexes (npBAP)xCuOAc preferably to form the insoluble tetranuclear (npBAP)2(CuOAc)4 complex 1. The crystal structure analysis of 1·2CH2Cl2, grown from CH2Cl2-hexane, reveals two μ(2)-P coordinated ligands, folding the Cu4 ring with each two short distances of the cyclic copper(I) acetate tetramer to a butterfly arrangement. AIM analysis of the ωB97-D/6-31+G* electron density, obtained at the crystal structure geometry, shows bond critical points between the copper atoms indicating covalent bonding interactions between the neighboring Cu atoms.