Bis Phosphine Oxide Research Articles

High lasing oscillation efficiency of Eu(III) complexes having remarkably sharp emission band

Luminescent Eu(III) complexes with bis-phosphine oxide ligands were synthesized. Geometric structures of novel Eu(III) complexes were determined by single-crystal X-ray diffraction. One of the Eu(III) complexes showed remarkably sharp red emission and large stimulated emission cross-section (full width at half maximum (FWHM) = 2.1 nm, stimulated emission cross-section = 1.80 × 10 −20 cm 2). The sharpness of the emission bands of the Eu(III) complexes was discussed in terms of the symmetry of the geometrical structure.

Synthesis and Characterization of a Novel Phosph(V)azane-Tin(IV) Complex

The reaction of bis(anilino)phosphine oxide (C6H5NH)2P(O)H, 1 with Bu2 nSnCl2 in the presence of an excess of triethylamine (TEA) in dry tetrahydrofurane (THF) yields the novel N,O-bonded tin complex Bu2 nSn[NPh(O)P(H)NPh(HNEt3)]2, 2. TEA is used as a base to deprotonate the phosphazane ligand and is separated as Et3NH+Cl−, whereas HTEA+ exists in the final product 2 and act as a charge balancing and H-bond structure–directing agent. This new compound has been fully characterized by means of IR, MS, and multinuclear (1H, 31P, and 119Sn NMR) spectroscopy.

Unexpected double α,β-addition of secondary phosphine chalcogenides to 3-phenyl-2-propynenitrile

Bis(2-phenylethyl)phosphine oxide and sulfide react with 3-phenyl-2-propynenitrile in the presence of KOH under mild conditions to form unexpectedly α,β-diadducts, 2,3-bis[bis(2-phenylethyl)phosphoryl]- and 2,3-bis[bis(2-phenylethyl)phosphorothioyl]-3-phenylpropionitriles.

Synthesis of Tertiary Bisphosphine Oxides from Methylacetylene and Secondary Phosphine Oxides.

Synthesis of Tertiary Bisphosphine Oxides from Methylacetylene and Secondary Phosphine Oxides.

Novel phosphorilated flame retardant thermosets: epoxy–benzoxazine–novolac systems

Modified novolac resins with benzoxazine rings were prepared and cured with isobutyl bis(glycidylpropylether) phosphine oxide (IHPOGly) as crosslinking agent. Their curing behaviour using different epoxy/phenol molar ratios and with or without triphenylphosphine as catalyst was studied. Two different phenolic groups react with oxirane ring, those initially free and those generated after benzoxazine ring opening. In absence of catalyst, it is not possible to distinguish between them. However, for the catalyzed curing of the highest modification degree benzoxazine based novolac resin is possible to distinguish both reactions. The thermal, thermomechanical and flame retardant properties of the cured materials were measured. V–O materials were obtained when the resins were tested for ignition resistance with the UL-94 test.

Phosphine Oxides as Efficient Neutral Coordinate‐Organocatalysts for Stereoselective Allylation of N‐Acylhydrazones.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Novel flame‐retardant thermosets: Phosphine oxide‐containing diglycidylether as curing agent of phenolic novolac resins

AbstractPhosphorus‐containing novolac–epoxy systems were prepared from novolac resins and isobutyl bis(glycidylpropylether) phosphine oxide (IHPOGly) as crosslinking agent. Their curing behavior was studied and the thermal, thermomechanical, and flame‐retardant properties of the cured materials were measured. The Tg and decomposition temperatures of the resulting thermosets are moderate and decrease when the phosphorous content increases. Whereas the phosphorous species decrease the thermal stability, at higher temperatures the degradation rates are lower than the degradation rate of the phosphorous‐free resin. V‐O materials were obtained when the resins were tested for ignition resistance with the UL‐94 test. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3516–3526, 2004

Synthesis, resolution, and application of 2,2′-bis(diphenylphosphino)-3,3′-binaphtho[b]furan (BINAPFu)

(±)-2,2′-Bis(diphenylphosphino)-3,3′-binaphtho[2,1-b]furan (BINAPFu) was synthesized from 2-naphthoxyacetic acid in a five-step sequence in 62% overall yield. A variety of reported resolution procedures for biaryl bisphosphines did not work with (±)-BINAPFu; thus, a new resolution method was developed, involving the Staudinger reaction of the aforementioned racemate of BINAPFu with an enantiopure camphor sulfonyl azide derivative. The resulting diastereomeric phosphinimines were separated by flash chromatography. Subsequent hydrolysis to the corresponding bis-phosphine oxide and trichlorosilane reduction provided enantiopure BINAPFu. The absolute stereochemical configuration of BINAPFu was established by X-ray crystallography. BINAPFu was compared with commercially available 2,2′-bis(diphenylphosphino)-1,1′-binaphthalene (BINAP) in Pd(0)-catalyzed intermolecular Heck reactions. Investigation of the Heck arylation of 2,3-dihydrofuran showed BINAPFu to be more efficacious than BINAP in dioxane at 30 °C. A variety of phosphorus selenides were prepared, and the 1JP-Se coupling constants measured, to obtain a comparative scale of parent phosphine basicity. The phosphorus atoms in BINAPFu were found to be electron deficient when compared with BINAP but slightly more electron rich than trifurylphosphine. Key words: naphthofurans, atropisomers, electron-deficient phosphines, asymmetric Heck reactions, Staudinger reaction.

Phosphine oxides as efficient neutral coordinate-organocatalysts for stereoselective allylation of N-acylhydrazones.

Phosphine oxides were found to be efficient neutral coordinate-organocatalysts (NCOs) for the allylation of N-acylhydrazones. Among the phosphine oxides tested, a three carbon-tethered bisphosphine oxide (dppp dioxide) was found to be the most effective, and in the presence of dppp dioxide, less reactive aromatic and [small alpha],[small beta]-unsaturated N-acylhydrazones underwent allylation as well as diastereoselective crotylation. Furthermore, a polymer-supported phosphine oxide was also developed as an effective immobilized NCO.

Synthesis of Tertiary Bisphosphine Oxides from Methylacetylene and Secondary Phosphine Oxides

Synthesis of Tertiary Bisphosphine Oxides from Methylacetylene and Secondary Phosphine Oxides

Cross‐Metathesis, a Versatile Synthetic Methodology for the Construction of Alkenyl Phosphine Oxides and Bis‐Phosphine Oxides.

Substituted vinyl and allyl phosphine oxides have been prepared by olefin cross-metathesis providing exclusive E olefin stereochemistry. The methodology has been successfully extended to the preparation of various bis-phosphine oxides.

Rotational barriers in dialkylaminochlorophosphines: methyl-substituted piperidinochlorophenylphosphines

Barriers to rotation about the P–N bond in a series of substituted piperidinochlorophenylphosphines were measured. The barriers for piperidine, 2-methylpiperidine and cis-2,6-dimethylpiperidine are the same within experimental error. The thermal condensation of the corresponding bis(piperidino)phosphine oxides with Mo(CO) 6 show that only the cis-2,6-dimethyl compound produces significant quantities of the [R 2NPO] 4[Mo(CO) 4] 2 complex. These observations are explained in terms of the steric requirements of the various amines and aminophosphines via cone angle measurements. Condensation of the mixed phosphine oxide, ( iPr 2N)(Et 2N)PHO, with Mo(CO) 6 produces [Et 2NPO] 4[Mo(CO) 4] 2.

Cross-metathesis, a versatile synthetic methodology for the construction of alkenyl phosphine oxides and bis-phosphine oxides

Substituted vinyl and allyl phosphine oxides have been prepared by olefin cross-metathesis providing exclusive E olefin stereochemistry. The methodology has been successfully extended to the preparation of various bis-phosphine oxides.

A series of new high‐performance materials based on poly[4′‐fluorophenyl‐bis(4‐phenyl)phosphine oxide

AbstractA new series of high‐performance poly(arylene phosphine oxide) (PAPO) materials were synthesized postpolymerization from fluorinated poly(arylene phosphine oxide) (f‐PAPO). The new materials had increased solubility and film‐forming ability over the parent f‐PAPO. With the careful choice of the nucleophile, the thermal stability was also increased. The parent polymer f‐PAPO was synthesized via Ni(0) coupling from aromatic chloride and mesylate monomers. Both monomers were polymerized successfully to create polymers with intrinsic viscosities of 0.235 and 0.123 dL/g, respectively. The higher molecular weight f‐PAPO gave a glass transition of 320 °C and a char yield of 54% at 650 °C in air. The substitution of f‐PAPO via nucleophilic aromatic substitution produced PAPO thermoplastics with significant changes in the properties. The largest increase in the thermal stability relative to f‐PAPO was from 563 to 600 °C 10% weight‐loss values in nitrogen after the displacement of fluoride by 4‐aminophenol, which yielded poly[4‐(4‐aminopheonxyphenyl)bis(4′‐phenyl)phosphine oxide]. Additionally, the char yield increased from 54 to 71% in air at 650 °C. The solubility of the parent polymer was improved after substitution with 3‐tert‐butylphenol, n‐nonylamine, and poly(ethylene glycol)monomethyl ether. All of these became soluble in chloroform, N,N‐dimethylacetamide, and dimethyl sulfoxide. Copolymers were synthesized with 2,5‐dichloro‐4′‐fluorobenzophenone to improve the solubility of f‐PAPO without the loss of thermal stability. These copolymers also underwent nucleophilic aromatic substitution to create an epoxy cure agent that was used with the DEN 431 resin. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2277–2287, 2003

A New Methodology for Synthesis of a Chiral Phosphinocarboxylic Acid Through Michael Cyclization—Aldol Tandem Reaction of Chiral α,β,ψ,ω‐Unsaturated Bisphosphine Oxide and Application in Palladium‐Catalyzed Asymmetric Allylic Alkylation.

A New Methodology for Synthesis of a Chiral Phosphinocarboxylic Acid Through Michael Cyclization—Aldol Tandem Reaction of Chiral α,β,ψ,ω‐Unsaturated Bisphosphine Oxide and Application in Palladium‐Catalyzed Asymmetric Allylic Alkylation.

Probing the reactivity of photoinitiators for free radical polymerization: time-resolved infrared spectroscopic study of benzoyl radicals.

A series of substituted benzoyl radicals has been generated by laser flash photolysis of alpha-hydroxy ketones, alpha-amino ketones, and acyl and bis(acyl)phosphine oxides, all of which are used commercially as photoinitiators in free radical polymerizations. The benzoyl radicals have been studied by fast time-resolved infrared spectroscopy. The absolute rate constants for their reaction with n-butylacrylate, thiophenol, bromotrichloromethane and oxygen were measured in acetonitrile solution. The rate constants of benzoyl radical addition to n-butylacrylate range from 1.3 x 10(5) to 5.5 x 10(5) M(-1) s(-1) and are about 2 orders of magnitude lower than for the n-butylacrylate addition to the counterradicals that are produced by alpha-cleavage of the investigated ketones. Density functional theoretical calculations have been performed in order to rationalize the observed reactivities of the initiating radicals. Calculations of the phosphorus-centered radicals generated by photolysis of an acyl and bis(acyl)phosphine oxide suggest that P atom Mulliken spin populations are an indicator of the relative reactivities of the phosphorus-centered radicals. The alpha-cleavage of (2,4,6-trimethylbenzoyl)phosphine oxide was studied by picosecond pump-probe and nanosecond step-scan time-resolved infrared spectroscopy. The results support a mechanism in which the alpha-cleavage occurs from the triplet excited state that has a lifetime less than or equal to the singlet excited state.

ChemInform Abstract: Facile Synthesis of Chelating Bisphosphine Oxides and Bisphosphines via Palladium‐Catalyzed Bishydrophosphinylation Reactions.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Bis(hydroxymethyl)phosphine Oxides and Hydroxymethyl Phosphinic Acids as Phosphonic Acid Analogs

(2002). Bis(hydroxymethyl)phosphine Oxides and Hydroxymethyl Phosphinic Acids as Phosphonic Acid Analogs. Phosphorus, Sulfur, and Silicon and the Related Elements: Vol. 177, No. 8-9, pp. 2221-2222.

A new methodology for synthesis of a chiral phosphinocarboxylic acid through Michael cyclization-aldol tandem reaction of chiral alpha,beta,chi,psi-unsaturated bisphosphine oxide and application in palladium-catalyzed asymmetric allylic alkylation.

Upon successive treatment with lithium diisopropylamide and then benzaldehyde, a chiral alpha,beta,psi,omega-unsaturated bisphosphine oxide underwent Michael cyclization-aldol tandem reaction to afford the corresponding endo-alpha,beta-unsaturated cyclic bisphosphine oxides. Sequential stereoselective reduction and Horner-Wadsworth-Emmons olefination gave the corresponding monophosphine oxide. Oxidative conversion of an olefin moiety into a carboxyl group and subsequent deoxygenation of an oxide gave the corresponding chiral phosphinocarboxylic acid, which was successfully applied as a chiral and functionalized monophosphine ligand in a palladium-catalyzed asymmetric allylic alkylation.

ChemInform Abstract: Synthesis and Application of Chiral Bisphosphines Through Lithiation—Conjugate Addition Tandem Cyclization of Chiral α,β,ψ,ω‐Unsaturated Bisphosphine Oxide.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.