Vasili Miluykov

The Reaction of Cyclopropenylphosphonium Bromides with Sodium Polyphosphides as an Advanced Method of Synthesis of Sodium 1,2-Diphosphacyclopentadienides: Scope and Limitations

Abstract A new ring expansion reaction based on the interaction between 1,2,3-triarylcyclopropenylphosphonium bromide (1) and sodium polyphosphides gives sodium 3,4,5-triaryl-1,2-diphosphacyclopentadienides (2) containing various substituents in the para-position of the aryl groups with a high yield. However, this reaction of trialkylcyclopropenylphosphonium bromide (i.e., tri(tert-butyl)- or triisopropylcyclopropenylphosphonium bromide) does not result to the formation of sodium 1,2-diphosphacyclopentadienides. Supplemental materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

Comparative Study of Conjugational Effects in 3,4,5-Triaryl-1-R-1,2-Diphospholes and 3,4,5-Triaryl-1,2-Diphosphacyclopentadienide-Anions

GRAPHICAL ABSTRACT Abstract The strength of conjugation between the phosphorus ring of 3,4,5-triaryl-1,2-diphosphacyclopentadienide-anion and exocyclic phenyl groups has been quantitatively characterized by the use of Raman activities of the bands of the phenyl substituents and the structural parameters obtained by an X-ray diffraction study. It is shown that conjugation in 1,2-diphospholides is very similar to conjugation of phenyl groups with the diene system of 1-R-1,2-diphospholes. The conjugation produces a dramatic intensification of Raman bands and a simultaneous bathochromic shift of the whole electronic absorption spectra for both types of phosphorus heterocycles.

Versatile Cycloaddition Reactions of 1-Alkyl-1,2-Diphospholes

Abstract The reactivity of 1-alkyl-1,2-diphospholes in cycloaddition reactions with dienes, dienophiles or 1,3-dipoles was examined. 1-Alkyl-1,2-diphospholes (2 ) exhibit dual reactivity and act as diene toward maleic acid derivatives or as dienophiles with 2,3-dimethyl-1,3-butadiene. The 1-alkenyl-1,2-diphospholes (4 ) are readily involved in intramolecular [4 + 2] cycloaddition reactions leading to cage phosphines (5 ). Interaction of 1-alkyl-1,2-diphospholes (2) with 1,3-dipolar reagents (diphenyldiazomethane and nitrones) results in formation of the bicyclic phosphiranes (8) and dimers of 1-alkyl-1,2-diphosphole oxides (9) or bicyclic phosphine oxides (10) with a β-lactam moiety depending on temperature. GRAPHICAL ABSTRACT

Substituent effects in the asymmetric Diels-Alder cycloaddition of 3,4,5-triaryl-1-(+)-neomenthyl-1,2-diphospholes’ with maleic acid derivatives

GRAPHICAL ABSTRACT ABSTRACT Asymmetric phospha-Diels-Alder reactions involving new 3,4,5-triaryl-1-(+)-neomenthyl-1,2-diphosphole bearing a chiral auxiliary with maleic acid derivatives with diastereoselectivities up to 91% are described.

Enhancing the reactivity of 1,2-diphospholes in cycloaddition reactions

Summary Two different approaches have been employed to enhance the reactivity of 1-alkyl-1,2-diphospholes – the introduction of electron-withdrawing groups either at the phosphorus atoms or in the para-position of the arene ring. The alkylation of sodium 1,2-diphospha-3,4,5-triphenylcyclopentadienide with alkyl halides Hal-CH2-R (R = CN, COOEt, OMe, CH2OEt) results in corresponding 1-alkyl-3,4,5-triphenyl-1,2-diphospholes (alkyl = CH2CN (1a), CH2COOEt (1b), CH2OMe (1c), and (CH2)2OEt (1d)), which spontaneously undergo the intermolecular [4 + 2] cycloaddition reactions at room temperature to form the mixture of the cycloadducts, 2a–c, respectively. However the alkylation of sodium 1,2-diphospha-3,4,5-tri(p-fluorophenyl)cyclopentadienide with ethyl iodide leads to stable 1-ethyl-3,4,5-tris(p-fluorophenyl)-1,2-diphosphole (1e), which forms the [4 + 2] cycloadduct 2,3,4,4a,5,6-hexa(p-fluorophenyl)-1-ethyl-1,7,7a-triphospha-4,7-(ethylphosphinidene)indene (2e) only upon heating up to 60 °C. With further heating to 120 °C with N-phenylmaleimide, the cycloadducts 2a–c and 2e undergo the retro-Diels–Alder reaction and form only one product of the [4 + 2] cycloaddition reaction 3a–с, 3e with good yields up to 65%.

Crystal structure of cyclic tris­(ferrocene-1,1′-di­yl)

The molecular structure of the trinuclear title compound, [Fe3(C10H8)3] {systematic name: tris[μ-(η5:η5)-1,1′-bicyclopentadienyl]triiron(II)}, consists of three ferrocene subunits (each with an eclipsed conformation) that are condensed via C—C bonds of the fulvalene moieties into a cyclic trimer. The angles between the planes of the cyclopentadienyl (Cp) rings within the three fulvalene moieties are 76.1 (3), 80.9 (3) and 81.7 (3)°. In the crystal, C—H⋯π interactions between neighbouring molecules lead to the cohesion of the structure.

Functionalized Phosphonium Ionic Liquids: Synthesis and Application

GRAPHICAL ABSTRACT Abstract A series of phosphonium salts with sterically hindered cation But3P+(CH2COOEt)X− (X = Cl, BF4, N(SO2CF3)2) (1) was prepared for the first time. Palladium nanoparticles (PdNPs) stabilized by (1) showed moderate activity as catalyst in Suzuki cross-coupling reaction of bromoarenes and phenylboronic acid.

CCDC 1564112: Experimental Crystal Structure Determination

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Interaction of sodium pentaphospholide with dimethyl acetylenedicarboxylate—A simple route to sodium 2,3,4,5-tetra(methylcarboxy)-monophospholide

GRAPHICAL ABSTRACT ABSTRACT Herein, we report a simple and effective route to synthesis of sodium 2,3,4,5-tetra(methylcarboxy)-monophospholide (1) based on the reaction of NaP5 with dimethyl acetylenedicarboxylate (DMAD).

Binuclear 3,4,5-tris(para-chlorophenyl)-1,2-diphosphacyclopentadienyl nitrosyl nickel complex: Synthesis, molecular structure, and behavior in solution

GRAPHICAL ABSTRACT ABSTRACT A novel stable binuclear nitrosyl nickel(0) complex with bridging 3,4,5-tris(para-chlorophenyl)-1,2-diphospholyl ligands was synthesized and fully characterized by NMR spectroscopy and X-ray diffraction. The structure and stability of the obtained complex are compared with a similar complex with bridging 1,2,4-triphospholyl ligands.