Tricoordinate Phosphorus Research Articles

A topological electron density analysis of tricoordinate phosphorus inversion processes

This paper describes the application of topological electron density analysis to inversion processes in tricoordinate phosphorus systems. The calculations are at the Hartree-Fock self-consistent-field level using the 6-311G ∗∗ basis sets. Of particular interest are the approximate T-shaped transition states reported by Dixon and co-workers (J. Am. Chem. Soc., 108 (1986) 2461, 6821). The role that the lone pair of electrons on phosphorus plays in determining the geometry of the transition state is analyzed through the laplacian of the electron density. It is shown that the species that will invert through the T-shaped process have distances, from P to the maximum in the non-bonded charge concentration, ranging from 1.408 a.u. to 1.417 a.u., whereas those species that invert through the classical process have distances ranging from 1.432 a.u. to 1.452 a.u.

The Mechanism of Reactive Group Exchange at Tri-Coordinate Phosphorus Centre

Abstract Compounds of tricoordinate phosphorus are well known to have the ability to exchange some reactive groups bound to the P(II1) centre (scheme 1) or they may exchange reactive groups in result of the interaction with compounds of other heteroatoms like silicon (scheme 2) Particularly remarkable reactivity and often amazingly high selectivity are exhibited by systems involving R1 and R2 substituents increasing nucleophilicity of the phosphorus centre like dialkylamine groups. It was shown that in these systems ionic complexes are formed (scheme 3,4) which are stable on the NMR time scale at low temperatures. Variant temperature 31p and 29Si NMR studies of these complexes proved that they are true intermediates in the ligand exchange processes.

The Mechanism of Reactive Group Exchange at Tricoordinate Phosphorus Centre

The Mechanism of Reactive Group Exchange at Tricoordinate Phosphorus Centre

CHEMISTRY OF S-TRIFLUOROMETHYL ORGANOPHOSPHOROTHIOATES AND THEIR STRUCTURAL ANALOGS A CONVENIENT SYNTHESIS OF ORGANOPHOSPHORUS FLUORIDATES

Abstract New organophosphorus compounds containing one or two different S-trifluoromethyl functionalities are synthesized in the reaction between the tri-coordinate phosphorus esters and bis-(trifluoromethane) disulfide. The catalytic effect exerted by the nucleophilic species such as the fluoride anion or tertiary amine on the decomposition of S-trifluoromethyl organophosphorus derivatives is documented. This observation is utilized for the preparation of different types of organophosphorus fluoridates.

Optically active silyl esters of phosphorus. II. Stereochemistry of reactions with nucleophiles

We report the stereochemistry of reactions of various nucleophiles with optically active silyl esters of phosphorus of general formula: tBuPhP(X)OSiMePhNp (X = −(1), Oxygen (2), Sulfur (3), Selenium (4). The list of nucleophiles includes O,S,N,C nucleophiles as well as halides. The nucleophilic attack is essentially directed towards silicon. The phosphinous and phosphonic acid esters react with predominant retention of configuration at silicon atom, whereas the thiono and seleno phosphinic analogues give inversion at silicon centre. The stereochemical crossover is explained in terms of possible interaction of the electrophilic part of the nucleophile with the oxyphosphoryl group or tricoordinate phosphorus.

ChemInform Abstract: Phosphoranes Formed from the Condensaton of Tricoordinate Phosphorus Compounds with Phenanthraquinone.

AbstractPhenanthrenequinone (I) and the phosphorus compounds (II) are combined to form the adducts (III) which are directly characterized by NMR spectroscopic methods.

PHOSPHORANES FORMED FROM THE CONDENSATION OF TRICO-ORDINATE PHOSPHORUS COMPOUNDS WITH PHENANATHRAQUINONE

Abstract The synthesis of a range of monocyclic and bicyclic phosphoranes from the condensation of trico-ordinate phosphorus compounds with phenanthraquinone is reported together with their 31P, 1H and 13C nmr data. The phosphorus chemical shifts of these compounds range from +34 to -35 ppm but solvent effects on [sgrave]P and the retention of P–C coupling throughout the range indicate that all of these compounds are true phosphoranes.

NEW TRI-COORDINATED AND PENTACOORDINATED PHOSPHORUS COMPOUNDS AND A BORON SPIRANE INVOLVING AN ENOLPYRUVATE MOIETY. SYNTHESIS OF A HYDROXYPHOSPHORANE MODEL OF INTERMEDIATE PHOSPHORANES IN NUCLEOPHILIC SUBSTITUTION REACTIONS ON PHOSPHORIC ESTERS OF ENOLPYRUVIC ACID

Abstract Hydrido and hydroxyspirophosphoranes, cyclic tri-coordinated phosphorus compounds and a boron spirane involving a phenylenolpyruvate moiety were prepared from reactions between phenylpyruvic acid and phosphorus trichloride, or (and) chloro-2-dioxaphospholane 1,3,2, or (and) chloro-2-oxo-2-phenyl-4,5-dioxaphospholane 1,3,2, or (and) boric acid. The hydroxyphosphorane is a good model of the intermediate postulated in the hydrolysis of enolpyruvate phosphoric esters.

ChemInform Abstract: Isothiocyanates of Phosphorus Acids, N‐Phosphorylated Thiocarbamates and Thioureas

AbstractReview: (223 refs.

The kinetics and mechanism of the reactions of acyclic trico-ordinate phosphorus compunds with diethyl peroxide

The kinetics of the reactions of acyclic phosphinites, phosphonites, and phosphines with diethyl peroxide in benzene or acetonitrile as solvent are reported together with the activation parameters for phosphinites and phosphonites and Hammett ρ values for all three types of trico-ordinate phosphorus. The data reveal a bimolecular, non-polar transition state for each reaction with ρ values which are virtually independent of the nature of the trico-ordinate phosphorus species.

Kinetics and mechanism of the reaction of trico-ordinate phosphorus compounds with octasulphur

Kinetic data and activation Parameters are reported for the reactions of a series of phosphites, arylphosphonites, diarylphosphinites, and triarylphosphines with octasulphur (S8) in toluene as solvent. For the Phosphites the data are explained in terms of changes in p-character of the lone-pair orbital on Phosphorus and inductive electron donation by the alkyl groups. The rates of reaction of series of arylphosphonites, diarylphosphinites, and triarylphosphines correlate with the Hammett σ constants to give ρ values of –3.0, –3.0, and –2.5, respectively, and the results are discussed in terms of the Reactivity–Selectivity Principle and the biphilic mechanism for insertion of trico-ordinate phosphorus Into σ-bonds.

Stereochemistry of substitution at trico-ordinate phosphorus

Download options Please wait... Article information DOI https://doi.org/10.1039/P29840000553 Article type Paper Download Citation J. Chem. Soc., Perkin Trans. 2, 1984, 553-558 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions Stereochemistry of substitution at trico-ordinate phosphorus J. Nielsen and O. Dahl, J. Chem. Soc., Perkin Trans. 2, 1984, 553 DOI: 10.1039/P29840000553 To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Search articles by author John Nielsen Otto Dahl

Reaction of Tricoordinate Phosphorus Compounds with Pseudohalogens. Scope and Mechanism

Abstract The selectivity of sulphur, selenium and oxygen removal from pseudohalogens: phosphorus disulphides 1 and 2, diselenides 3 and oxophosphoranesulphenyl chlorides 4 has been investigated. A mechanistic rationalization is proposed to account for sulphur (selenium)/oxygen extrusion variation as a function of substrates structure and reaction conditions.

PENTACO-ORDINATE PHOSPHORUS COMPOUNDS BY NUCLEOPHILIC ADDITION TO ACTIVATED ALKENES AND ALKYNES IN THE PRESENCE OF ALCOHOLS AND PHENOLS

Abstract The reactions of a variety of trico-ordinate phosphorus compounds, Ar n P(OR)3-n (n = 1 or 2), and cyclic analogues, with acrylonitrile, ethyl acrylate or ethyl phenylpropiolate and alcohols or phenols in low polarity media gives rise to a wide range of pentaco-ordinate phosphorus compounds. Attempts to extend this synthetic route to phosphoranes containing P[sbnd]N or P[sbnd]S bonds met with no success.

A new stable tricoordinate phosphorus(V) compound: P-2,6-dimethylphenyl- C, C-diphenylselenophosphene

Reaction of 2,6-dimethylphenyl(diphenylmethylene)phosphine ( 1) with selenium in benzene leads to the compound P-2,6-dimethylphenyl- C, C-diphenylselenophosphene ( 2c). Compound 2c is stable at room temperature, but decomposes on heating with partial regeneration of the starting materials. Ethanol adds to the PC bond of 2c to give the selenophosphinate 3c. No reaction was observed between 1 and tellurium.

Phosphino sulphonates, a type of PIII-anhydride and their isomerisation into phosphinoyl sulphinates: a novel rearrangement in phosphorus–sulphur chemistry

The imidazolides (1) react smoothly with RSO3H to afford a novel class of trico-ordinate phosphorus anhydride, the phosphino sulphonates (2); under sutable structure circumstances the compounds (2) undergo a novel type of rearrangement, (2)→(6), which provides the first example of a phosphinoyl sulphinate structure (6).

The reaction of 1-substituted 3,4-dimethyl-Δ3-phospholens with diethyl peroxide: a correlation between rate and31P nuclear magnetic resonance shift

The reactions of a variety of 1-X-3,4-dimethyl-Δ3-phospholens (where X = Br, Me, Ph, NMe2, SEt, H, and OR) with diethyl peroxide are described. The rates of reaction show a broad correlation with the 31P n.m.r. chemical shifts of the starting phospholens, with low field shifts corresponding to the highest reactivity. The results are discussed in terms of the biphilic mechanism for the reaction of trico-ordinate phosphorus compounds with weak σ-bonds.

Pentaco-ordinate phosphorus compounds by nucleophilic addition to activated alkenes

The reactions between a variety of trico-ordinate phosphorus compounds and acrylonitrile or ethyl acrylate provide a novel route to pentaco-ordinate phosphorus compounds.

ChemInform Abstract: 2,5‐DIHYDRO‐1,3,2‐OXAZAPHOSPH(V)OLES. PREPARATION AND PROPERTIES

AbstractDie Azidooxirane (I) liefern mit den Phosphinen (II) in Pentan oder Ether bei 0 bis 25°C die Oxazaphosphole (III).

2,5-Dihydro-1,3,2-oxazaphosph(V)oles. Preparation and properties

2,5-Dihydro-1,3,2-oxazaphosph(V)oles, prepared by reaction of 2-azido-oxirans with trico-ordinated phosphorus compounds, exhibit a trigonal bipyramidal structure with the sp2 nitrogen atom apical and the oxygen atom equatorial.