Bis Phosphine Oxide Research Articles

ChemInform Abstract: Synthesis of Optically Pure Bisphosphine Oxides and Related Compounds.

ChemInform 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.

ChemInform Abstract: Using Polarization Effects to Alter Chemical Reactivity: A Simple Host Which Enhances Amine Nucleophilicity.

The rational design of a bis(phosphine oxide) host which is capable of binding a benzylic amine is presented. The ability of this host to increase the rate of addition of 4-fluorobenzylamine to N-phenylmaleimide is rationalized in terms of the enhancement of the nucleophilicity of the benzylic amine.

Reaction of secondary phosphine oxides with acylacetylenes

Secondary phosphine oxides reacted with 1-alkanoyl-2-phenylacetylenes in chemoselective fashion under mild conditions (20°C, THF) in the absence of a catalyst (diphenylphosphine oxide) or in the presence of potassium hydroxide [bis(2-phenylethyl)phosphine oxide] to give 1-alkyl-1-diphenyl(or 2-phenylethyl)-phosphoryl-3-phenylprop-2-yn-1-ols in up to 96% yield. The reaction of diphenylphosphine oxide with 1-alkanoyl-2-phenylacetylenes in the system KOH-THF (20°C) afforded not only adducts at the carbonyl group but also products of double α,β-addition at the triple bond, 2,3-bis(diphenylphosphoryl)-3-phenylpropan-1-ones.

Evaluation of acylphosphine oxide polymerization initiators using differential scanning calorimetry

This study examines the polymerization of dental monomers catalyzed by synthesized acylphosphine oxides in a differential scanning calorimetry (DSC) cell. This research focuses on establishing a relationship between radicals generated by the acylphosphine oxide photoinitiators and the kinetic reaction rates of methyl methacrylate (MMA) and acrylamide (ACM), a model monomer. The thermal stability of mono- and di-acylphosphine oxides was examined by DSC. Endothermic melting and exothermic polymerization reactions initiated with the two initiators were recorded. The acrylamide model system laid the ground work for the critical evaluation of the synthesized new initiators of mono (2,4,6-trimethylbenzoyl) diphenylphosphine oxide, and bis(2,4,6-trimethylbenzoyl) phenylphosphine oxide. The bis(acyl) phosphine oxide photoinitiator was more reactive than the mono-(acyl) phosphine oxide with methyl methacrylates under laboratory conditions. In exothermic reactions, temperatures rose higher and more rapidly for bis(acyl) phosphine oxide initiated reactions than mono-(acyl) phosphine oxide initiated reactions.

Synthesis and oxidation of (4-hydroxy-3,5-di-tert-butylphenyl)-methanebis[diethyl(diphenyl)phosphine oxides

The phosphorylated sterically hindered phenols and methylenequinones are potential inhibitors of oxidation of organic materials like polymers, petrochemical products, and biological systems [1–2]. In extension of studying the reaction of geminal polyhalides with aprotic nucleophilic reagents [3–5] we studied the reaction of 4-hydroxy-3,5-di-tert-butylbenzal chloride I with diethyl and diphenyl chlorophosphines. The reaction of dichloride I with diethyl chlorophosphine was found to proceed at keeping the hexane solution of reagents taken in the ratio 1:2 at room temperature for 24 h. The reaction of dichloride I with diphenyl chlorophosphine requires the heating of the reagents mixture at 100–110°С for 3 h. Adducts III form in high yields as colorless hygroscopic viscous products, weakly fuming in the air. According to the Р NMR spectra, compounds IIIa (δP 69.36 ppm) and IIIb (δP 71.02 ppm) have phosphonium structure in keeping with the literature data [6, 7]. The treatment of adducts IIIa and IIIb with anhydrous ethanol followed by evaporating of the solvents in a vacuum gives the corresponding bisphosphine oxides IV. DOI: 10.1134/S1070363210030278

Role of Bimolecular Homolytic Substitution (SH2) Reactions in Free Radical Photopolymerization Under Air

A set of multivalent atom-containing amines (e.g., tetrakis(dimethylamido)silane, tetrakis(dimethylamido)tin(IV), tetrakis(diethylamido)titanium(IV), tetrakis(dimethylamido)zirconium(IV), and 1,3,5-triaza-7-phosphaadamantane) are proposed as new coinitiators in Type II photoinitiating systems (based, for example, on benzophenone) and additives for Type I photoinitiators (such as phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide and 2-hydroxy-2-methyl-1-phenyl-1-propanone) for free radical photopolymerization under air. The polymerization rates (Rp’s) were determined under experimental conditions where a strong detrimental oxygen effect is expected, that is, both under low light intensity and in thin low viscosity monomer samples. The remarkable performance achieved under air (up to a 100- and a 5-fold increase in Rp and final conversion (%), respectively) lies on the presence of a bimolecular homolytic substitution (SH2) reaction that allows us to convert peroxyls into new initiating radicals efficiently. The mechanisms are investigated by laser flash photolysis (LFP) and electron spin resonance (ESR) experiments.

Reaction of secondary phosphine chalcogenides with 2,2,2-trichloroacetaldehyde

The nucleophilic addition of secondary phosphine chalcogenides to 2,2,2-trichloroacetaldehyde proceeds under mild noncatalytic conditions (12–25dgC, 15–90 min) with the formation of functional tertiary phosphine chalcogenides, containing hydroxy groups in up to 98% yield. Using the method of concurrent reactions the reactivity of secondary phosphine chalcogenides in this reaction was shown to decrease in the order: (PhCH2CH2)2P(O)H ≫ (PhCH2CH2)2P(S)H > (PhCH2CH2)2P(Se)H, and the secondary bis[2-(2-pyridyl) ethyl]-phosphine oxide was more reactive than bis(2-phenethyl)phosphine oxide.

Allenes in asymmetric catalysis: asymmetric ring opening of meso-epoxides catalyzed by allene-containing phosphine oxides.

Unsymmetrically substituted allenes (1,2-dienes) are inherently chiral and can be prepared in optically pure form. Nonetheless, to date the allene framework has not been incorporated into ligands for asymmetric catalysis. Since allenes project functionality differently than either tetrahedral carbon or chiral biaryls, they may create complementary chiral environments. This study demonstrates that optically active, C(2)-symmetric allene-containing bisphosphine oxides can catalyze the addition of SiCl(4) to meso-epoxides with high enantioselectivity. The epoxide opening likely involves generation of a Lewis acidic, cationic (bisphosphine oxide)SiCl(3) complex. The fact that high asymmetric induction is observed suggests that allenes may represent a new platform for the development of ligands and catalysts for asymmetric synthesis.

Synthesis and Characterization of a Novel Phosph(V)azane-Platinum(II) Complex

The substitution reaction of bis(anilino)phosphine oxide (C 6 H 5 NH) 2 P(O)H (1) with trans-PtCl 2 (SEt 2 ) 2 yields the novel unprecedented phosph(V)azane-platinum complex cis-Pt(SEt 2 ) 2 Cl[HNPhP(O)NPh(HNEt 3 )] (3). In this reaction, the bis(anilino)phosphine oxide undergoes P–H activation and a Pt(II)–P(V) bond instead of Pt–N bond forms. 31 P NMR spectra readily distinguish between the “N” and “P” bonding modes. The reaction requires the presence of triethylamine (TEA) as a base in order to deprotonate the phosphazane ligand and is separated as Et 3 NH+Cl−, whereas HTEA+ exists in the final product 3 and is acting as charge balancing and H-bond structure directing agent. The products have been fully characterized by means of IR; MS; UV-Vis; and 1 H, 13 C, and 31 P NMR spectroscopy.

Synthesis and Characterization of New Silicon and Titanium Derivatives of Bis(anilino)phosphine Oxide

The reactions of bis(anilino)phosphine oxide (C 6 H 5 NH) 2 P(O) H with (C 5 H 5 )2TiCl2 or Me2SiCl2 in a 1:1 molar ratio in THF results in the isolation of new phosph(V)azane complexes (C5H5)2Ti[(N C6H5)2P(O)H] (1) or Cl 2 Si[(N C 6 H 5 )2P(O)H] (2), respectively. In these reactions, HCl or CH4 elimination occurs and N-Ti or N-Si bonds form directly between a bis(anilino)phosphine oxide ligand and organotitanium or organosilicon compounds. The products(1) and (2) have been fully characterized by elemental analysis as well as 1 H, 31 P, 29 Si NMR, and IR spectroscopy.

Selective mono reduction of bis-phosphine oxides under mild conditions

Bis-phosphine oxides can be selectively reduced to bis-phosphine monoxides under exceptionally mild conditions using triflic anhydride and a thiol.

Solid-state 115In NMR study of indium coordination complexes

The feasibility of solid-state (115)In NMR studies is demonstrated by an examination of four different coordination complexes: indium(III) acetylacetonate, indium(III) tris(tropolonato), indium(III) triiodide bis(tris(4-methoxyphenyl)phosphine oxide) and indium(III) trichloride tris(2,4,6-trimethoxyphenyl)phosphine. The results provide information about the electric field gradients and magnetic shielding at the indium nuclei through the nuclear quadrupolar and chemical shift parameters, respectively. The C(Q) values in these four complexes range between 106.0 +/- 2.0 and 200.0 +/- 4.0 MHz, while the magnetic shielding anisotropies fall in the range from 85 +/- 15 to 550 +/- 60 ppm. Finally, this research demonstrates that solid-state (115)In NMR studies are facilitated by performing experiments at the highest possible magnetic-field strengths, and that NMR offers a promising tool for the characterization of indium compounds.

Development of Novel Rare-Earth Complexes and Their Application to Emission Devices

Colorless and transparent emission materials are being rapidly developed in view of their potential for use in emission devices, ornaments, and other applications. We focused on rare-earth complexes because of their transparency when dissolved in polymer and pure color emission. The first concept of novel molecular design of rare-earth complexes, namely, introduction of two different phosphine oxides into one rare-earth ion as ligands, was established, and their solubility and emission intensity were drastically enhanced. The second concept is that two different phosphine oxides are tied together and asymmetric bis-phosphine oxide structure is introduced to one rare-earth ion. The emission intensity of an Eu(III) complex was further enhanced. Colorless and transparent emission materials using novel rare-earth complexes have excellent transparency and strong pure color emission, and are promising candidates for a variety of application fields, including emission devices, where the see-through feature will be essential.

Nucleophilic addition of secondary phosphine chalcogenides to, α,β-acetylenic γ-hydroxy acid nitriles and a rearrangement of the adducts

Bis(2-phenylethyl)phosphine oxide and sulfide and bis[2-(2-pyridyl)ethyl]phosphine sulfide add easily (LiOH–THF, 28–30 °C) to 4-hydroxy-4-methyl-2-pentynenitrile to give regio- and stereoselectively 3-substituted ( Z )-4-hydroxy-4-methyl-2-pentenenitriles in 82–91% yield; the latter, upon heating (58–60 °C) in the presence of LiOH in THF, rearrange cleanly to the corresponding 3-cyano-2-propen-1-yl phosphinates and phosphinothioates (isolated yields of 82–86%).

New Phosph(V)azane Ligand as a Bidentate Donor in the Synthesis of One Novel Organometallic Tin(IV) Compound

The new ligand {[(C6H5NH)P(O)H](NC6H5)[(C6H5NH)P(O)H]} ( 2 ) was synthesized by heating bis(anilino)phosphine oxide (C6H5NH)2P(O)H ( 1 ) at 110°C and elimination of aniline. The treatment of 2 with SnBu2 Cl2 in the presence of triethylamine (TEA) in dry THF yielded the novel compound Bu n 2Sn{[Et3NH(NPh)P(O)H](NPh)p(O)H]}2 ( 3 ) in which the phosphazane ligand acts as a bidentate ligand. The products have been characterized by means of elemental analysis, IR, MS, and multinuclear NMR ( 1H, 13C, 31P, and 119Sn) spectroscopy. The spectroscopic data are consistent with the bounding of the phosph(V)azane ligand through both oxygen and phosphorus atoms to Sn(IV) center in the final compound 3 . TEA is used as a base in order to deprotonate the phosphazane ligand and is separated as Et3 NH + Cl − , whereas HTEA + exists in the title product 3 and is acting as a charge balancing and H-bond structure directing agent.

Multiporphyrin coordination arrays based on complexation of magnesium(ii) porphyrins with porphyrinylphosphine oxides

Di- and triporphyrin arrays consisting of 5,15-diphenylporphyrinatomagnesium(II) (MgDPP) coordinated to free-base and Ni(II) porphyrinyl mono- and bis-phosphine oxides, as well as the self-coordinating diphenyl[10,20-diphenylporphyrinatomagnesium(II)-5-yl]phosphine oxide [MgDPP(Ph(2)PO)], were synthesised in excellent yields and characterised by various spectroscopic techniques. Phosphine oxides stabilise Mg(II) coordination to porphyrins and the resulting complexes have convenient solubilities, while the Ni(II) complexes exhibit interesting intramolecular fluorescence quenching behaviour. The binding constant of MgDPP to triphenylphosphine oxide (5.3 +/- 0.1 x 10(5) M(-1)) and the very high self-association constant of [MgDPP(Ph(2)PO)] (5.5 +/- 0.5 x 10(8) M(-1)) demonstrate the strong affinity of phosphine oxides towards Mg(II) porphyrins. These complexes are the first strongly bound synthetic Mg(II) multiporphyrin complexes and could potentially mimic the "special pair" in the photosynthetic reaction centre.

Ytterbium‐Catalyzed Dual Intermolecular Hydrophosphination: Synthesis of Bis(phosphinyl)dienes and Bis(alkenyl)phosphine Oxides.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

A Novel Synthesis of AlCl[(NPh)2P(O)H] and SiCl2[(NPh)2P(O)H]: Two New Phosph(V)azane Derivatives

Reactions of phosph(V)azane derivatives of bis(anilino)phosphine oxide (PhNH)2P(O)H (1) with AlCl3 and SiCl4 produce two new phosph(V)azane complexes, AlCl[(NPh)2P(O)H] (2) and SiCl2[(NPh)2P(O)H] (3). In these reactions, an HCl elimination occurs and M─N bonds (M = Si, Al) form directly between a bis(anilino)phosphine oxide ligand with aluminum and silicon halides. The reactions do not require any base to deprotonate the phosphazane ligand. The final products have been fully characterized by means of elemental analysis and IR, MS, and multinuclear NMR (1H, 13C, 31P, 27Al, and 29Si) spectroscopy.

Ytterbium-catalyzed dual intermolecular hydrophosphination: synthesis of bis(phosphinyl)dienes and bis(alkenyl)phosphine oxides

Dual intermolecular hydrophosphination of conjugated diynes with 2 equiv of diphenylphosphine was catalyzed by ytterbium complexes, Yb( η 2-Ph 2CNPh)(hmpa) 3 ( 1 ) and Yb[N(SiMe 3) 2] 3(hmpa) 2 ( 2 ), to give the corresponding 1,4-bis(diphenylphosphinyl)buta-1,3-dienes in high yields after oxidative work-up. Distribution of the four possible stereoisomers sharply depended on substituents of the substrates. ( Z, Z)-Isomers were predominantly obtained from the disubstituted diynes, together with minor ( Z, E)-isomers. On the other hand, the reaction of the terminal diynes provided major ( E, Z) and minor ( E, E)-butadienes. 1,4-Di- tert-butylbuta-1,3-diyne was exclusively converted to an allenic compound. Moreover, the dual hydrophosphination using phenyphosphine was also performed with 1 and 2 . Thus, the reaction of 2 equiv of aromatic alkynes with PhPH 2 and subsequent oxidation gave bis(alkenyl)phosphine oxides in preference of the ( Z, Z)-stereoisomers.

The Molecular Structures and Properties of Novel Eu(III) Complexes with Asymmetric Bis-phosphine Oxides

ABSTRACTSeveral novel Eu(III) complexes with asymmetric bis-phosphine oxide- ligands were synthesized. The relation between molecular structures of bis-phosphine- oxide ligands and properties of Eu(III) complexes was investigated and some interesting results were obtained. Solubility of Eu(III) complexes in fluorinated medium and silicone oil were strongly dependent on the length of alkyl chain (n) binding two phosphine oxide- parts. Also, the thermal properties of Eu(III) complexes were correlated to the solubility. Eu(III) complex 6(n=3), which has phenyl and n-octyl groups as the substituents of a bis-phosphine oxide- ligand, was found to be highly soluble and have large fluorescence intensity.