- Gas-Phase Chemistry of H2P(-)
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The gas-phase ion-molecule chemistry of H2P(-) has been investigated by using the flowing afterglow technique.Generated by proton abstraction from PH3 by H2N(-) or OH(-), H2P(-) reacts with N2O, CO2, OCS, CS2, O2, NO2, SO2, CH3X, and (CH3)3SiCl to yield a variety of ion products.Products usually arise from initial nucleophilic attack of H2P(-) on the neutral, followed by intramolecular proton transfer and/or expulsion of a neutral fragment.Many of the reactions are similar to those for H2N(-), though differences are attributable to the weaker nucleophilicity of H2P(-).Product branching ratios and reaction rate constants are reported, and possible mechanistic pathways are discussed.
- Anderson, David Richard,Bierbaum, Veronica M.,DePuy, Charles H.
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- ANTI-BACTERIAL COMPOUNDS BASED ON AMINO-GOLD PHOSPHINE COMPLEXES
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A compound of formula (I) for use in the prevention or treatment of a bacterial infection wherein: PX is selected from the group consisting of (P1), (P2) and (P3).
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Page/Page column 76
(2017/06/30)
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- The Ever-surprising chemistry of boron: Enhanced acidity of phosphine·boranes
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The gas-phase acidity of a series of phosphines and their corresponding phosphine·borane derivatives was measured by FT-ICR techniques. BH 3 attachment leads to a substantial increase of the intrinsic acidity of the system (from 80 to 110 kJ mol-1). This acidity-enhancing effect of BH3 is enormous, between 13 and 18 orders of magnitude in terms of ionization constants. This indicates that the enhancement of the acidity of protic acids by Lewis acids usually observed in solution also occurs in the gas phase. High- level DFT calculations reveal that this acidity enhancement is essentially due to stronger stabilization of the anion with respect to the neutral species on BH3 association, due to a stronger electron donor ability of P in the anion and better dispersion of the negative charge in the system when the BH3 group is present. Our study also shows that deprotonation of ClCH2PH2 and ClCH 2PH2·BH3 is followed by chloride departure. For the latter compound deprotonation at the BH3 group is found to be more favorable than PH2 deprotonation, and the subsequent loss of Cl- is kinetically favored with respect to loss of Cl - in a typical SN2 process. Hence, ClCH2PH 2·BH3 is the only phosphine·borane adduct included in this study which behaves as a boron acid rather than as a phosphorus acid.
- Hurtado, Marcela,Yanez, Manuel,Herrero, Rebeca,Guerrero, Andres,Juan Z. Davalos,Jose-Luis, M. Abboud,Khater, Brahim,Guillemin, Jean-Claude
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supporting information; experimental part
p. 4622 - 4629
(2009/12/29)
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- Synthesis, photoelectron spectroscopy and quantum chemical study of kinetically unstabilized phosphines complexed by borane
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Ethynyl- and allenylphosphine-boranes have been prepared by addition at low temperature of borane on the free phosphine. Purification was performed by selective trapping in vacuo and the complexes were characterized by NMR and infrared spectroscopy and ma
- Nemeth, Balazs,Khater, Brahim,Veszpremi, Tamas,Guillemin, Jean-Claude
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body text
p. 3526 - 3535
(2009/09/07)
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- More user-friendly phosphines? Molecular structure of methylphosphine and its adduct with borane, studied by gas-phase electron diffraction and quantum chemical calculations
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The molecular structures of methylphosphine (CH3PH2) and methylphosphine-borane (CH3PH2?BH3) have been determined from gas-phase electron diffraction data and rotational constants, employing the SARACEN method. The experimental geometric parameters generally showed a good agreement with those obtained using ab initio calculations and previous microwave spectroscopy studies. In order to assess the accuracy of the calculated structures a range of ab initio methods were used, including the CCSD(T) method, with correlation-consistent basis sets. The structural environment around the phosphorus atom was found to change significantly upon complexation with borane, with the P-C bond length shortening and the bond angles widening. The Royal Society of Chemistry 2008.
- Noble-Eddy, Robert,Masters, Sarah L.,Rankin, David W. H.,Wann, Derek A.,Khater, Brahim,Guillemin, Jean-Claude
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supporting information; experimental part
p. 5041 - 5047
(2009/02/06)
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- B(C6F5)3-catalyzed silylation versus reduction of phosphonic and phosphinic esters with hydrosilanes
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HSiR3/cat-B(C6F)3 induced dealkylation or reduction of esters of phosphorus at 20°C. A specific conversion to silylesters occurred by reaction with tertiary silanes. In contrast, free phosphines were observed in the reaction with mono- or disubstituted silanes. A mechanism was proposed to rationalize these results.
- Denis, Jean-Marc,Forintos, Henrietta,Szelke, Helga,Keglevich, Gy?rgy
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p. 5569 - 5571
(2007/10/03)
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- Reaction of dichlorophosphines with glycidol. New data on the transformations of cyclic phosphonates
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Reaction of dichlorophosphines with glycidol yields 2-R-4-chloromethyl-1,3,2-dioxaphospholanes as primary products, which under the reaction conditions or under the action of HC1 surprisingly readily undergo redox transformations yielding 2-R-4-chloromethyl-1,3,2-dioxaphospholane 2-oxides, dichloropropyl R-phosphinates, bis(dichloropropyl) R-phosphonates, and phosphines RPH2.
- Bredikhin,Lazarev,Efremov,Sharafutdinova,Bredikhina
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p. 708 - 713
(2007/10/03)
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- P-H bond activation of primary phosphine-boranes: Access to α-hydroxy and α,α′-dihydroxyphosphine-borane adducts by uncatalyzed hydrophosphination of carbonyl derivatives
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Primary P-phenyl and P-methyl phosphine-boranes 1 and 2 are prepared by complexation of the free phosphines with BH3 · SMe2. They are stable and can be purified by distillation. Under basic conditions, they lead selectively to secondary alkylphosphine-boranes and under neutral conditions to the corresponding mono- and bis-hydroxyphosphine-boranes 5 and 6. All these new compounds are purified by chromatography on silica gel. A competitive hydroboration induced by the decomplexation of BH3 is observed as a minor process. Conditions for the decomplexation of phosphine-borane adducts are presented.
- Bourumeau, Karine,Gaumont, Annie-Claude,Denis, Jean-Marc
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p. 205 - 213
(2007/10/03)
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- Synthesis of Primary and Secondary Phosphines by Selective Alkylation of PH3 under Phase Transfer Conditions
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Primary phosphines, RPH2, may be synthesized selectively by alkylation of phosphine, PH3, with alkyl halides RX (R = Me, Et, n-Bu, 2-Bu, C16H33, CH2=CH-CH2, Ph-CH2, 2-Py-CH2-CH2; X = Cl, Br) and concentrated aqueous KOH as auxilliary base in dimethylsulfoxide as a solvent or in two phase systems employing phase transfer catalysts.Under more rigorous conditions secondary phosphines R2PH (R = Me, n-Bu, CH2=CH-CH2) are also acessible in good yields.Using 1,3-dibromo(chloro)-propane or -butane diprimary phosphines H2P-(CH2)2-CHR-PH2 (R = H, Me) are obtaines, while 1,4-dibromopentane in a high yield cyclization reaction leads to 2-methylphospholane (12) with a chiral C-atom in α-position.
- Langhans, Klaus P.,Stelzer, Othmar
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p. 203 - 211
(2007/10/02)
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- SYNTHESIS OF PRIMARY α-CHLOROPHOSPHINES BY A CHEMOSELECTIVE REDUCTION OF α-CHLOROPHOPHONATES
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Reduction of chloromethylphosphonates with lithium aluminium hydride gave a mixture of chloromethylphosphine and methylphosphine, characterized by NMR, IR and mass spectra.Reduction of the same compounds by AlH3 gave chloromethylphosphine as nearly the only product.Extension of this reaction to the C-substituted derivatives gave the correspondeng α-chlorophosphines with good chemoselectivity.Keywords: Reduction of phosphonates; aluminium hydride; chemoselectivity; primary phosphines.
- Cabioch, Jean-Luc,Pellerin, Bruno,Denis, Jean-Marc
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- Capping Reactions of RuCo2(CO)11 with Main Group and Transition Element Reagents
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The reactive cluster RuCo2(CO)11 was treated with numerous inorganic, organo-element, and organic reagents which are potential precursors of μ3-bridging four electron ligands.Capping could be achieved with Co(CO)4- forming RuCo3(CO)12-, with RPH2 (R=Me, Ph, Tol) forming RuCo2(CO)9PR (3a-c), with MeAsH2 forming RuCo2(CO)9AsMe (4), with H2S, HSEt, or S8 forming RuCo2(CO)9S (5), with Ph2Se2 leading to RuCo2(CO)9Se (6), with TolC=-WCp(CO)2 forming RuCo2W(CTol)Cp(CO)10 (8), and with LnM-C=-CPh (Ln=Cp(CO)2Fe, Cp(CO)2Ru, Cp(CO)3W) forming RuCo2M(C2Ph)(CO)8Ln (9, 10, 12).With tBuC=-P and Cp(CO)2Mo=-MoCp(CO)2 fragmentation products were obtained, tBuNC led to CO substitution.The new tetranuclear clusters RuCo2W(CTol)Cp(CO)10 (8), RuCo2Fe(C2Ph)Cp(CO)10 (9), and RuCo2W(C2Ph)Cp(CO)11 (12) were confirmed by crystal structure analyses.
- Roland, Eckehart,Bernhardt, Wolfgang,Vahrenkamp, Heinrich
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p. 2566 - 2581
(2007/10/02)
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- Gas-Phase Chemistry of Trimethyl Phosphite
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The reactions of trimethyl phosphite, (CH3O)3P, with the nucleophiles H2N-, CH3NH-, (CH3)2N-, HO-, H(18)O-, CH3O-, CD3O-, H-, F-, H2P-, CH2=CH-CH2- and (CH3)2C=C(CH3)CH2- were investigated.Products, branching ratios, and reaction rate constants are reported.Reactions generally proceed through an ion-dipole complex -.(CH3O)3P>, to a phosphoranide anion intermediate, -> to displacement of methoxide to form a new ion-dipole complex -.(CH3O)2PZ>.If an additional acidic hydrogen is available on the nucleophile, the major products results from proton abstraction by methoxide: -(CH3O)2PYH> -> (CH3O)2PY- + CH3OH.When the displacement of methoxide from phosphorus is sufficiently endothermic, a competing attack at carbon by the original nucleophile occurs: -(CH3O)3P> -> CH3YH + (CH3O)2PO-.Nucleophiles without an additional acidic hydrogen reacts similarly, but the final reaction products result from (1) SN2 reaction of methoxide, -> -> Z(CH3O)PO- + CH3OCH3, (2) SN2 reaction of the original nucleophile, -(CH3O)3P> -> CH3Z + (CH3O)2PO-, (3) stabilization of the phosphoranide intermediate to give the adduct Z(CH3O)3P-, and (4) expulsion of methoxide from the ion-dipole complex.Reaction mechanisms are discussed in terms of the nature of the nucleophiles, the observed products, and the thermodynamics of the displacement reaction.
- Anderson, David R.,DePuy, Charles H.,Filley, Jonathan,Bierbaum, Veronica M.
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p. 6513 - 6517
(2007/10/02)
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- Oligophosphaalkanes, VI. Syntheses and NMR Spectroscopic Characterization of PH-functional Methylene Bridged Diphosphanes R2P-CH2-PRH and HRP-CH2-PRH
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1,3-Diphosphapropane, H2P-CH2-PH2 (1) was synthesized in about 40 percent yield by reduction of Cl2P-CH2-PCl2 with LiAlH4.The mono-, di-, and tri-substituted derivatives RHP-CH2-PH2 (R = iPr, CH2Ph, 3a, b) RHP-CH2-PHR (R = iPr, CH2Ph, tBu, 5a - c), R2P-CH2-PRH (R = Me, iPr, CH2Ph, 10b, 7a, b) are accessible using Cl2P-CH2-PCl2 as a starting material.A multiple stage synthesis based on MePCl2 affords the disecondary phosphane MeHP-CH2-PMeH (10d), which in contrast to reports given in the literature is thermally stable to at least 100 deg C.The 31P and 1H NMR spectra of 1 have been analyzed and simulated by use of computer programs.The structure of the phosphanes is discussed on the basis of their 1H, 31P, 31P, and 13C NMR spectra.
- Hietkamp, Sibbele,Sommer, Herbert,Stelzer, Othmar
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p. 3400 - 3413
(2007/10/02)
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- THE SYNTHESIS AND REACTIONS OF POTASSIUM BENZOYLPHOSPHIDE, BENZOYLPHOSPHINE, AND BENZOYLMETHYLPHOSPHINE.
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Reaction of potassium dihydrogenphosphide with aromatic esters produces potassium benzoylphosphide (1).Protonation of 1 produces benzoylphosphine 2.The physical and chemical properties of 1 and 2 are discussed.
- Liotta, Charles L.,McLaughlin, Mark L.,O'Brien, Brian A.
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p. 1249 - 1252
(2007/10/02)
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- Oligophosphine Ligands, I Convenient Syntheses of the Trimethylene-linked Triphosphines RP2 and their Precursors Ph2P(CH2)3P(H)R (R=Ph, Me)
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The secondary-tertiary diphosphines Ph2P(CH2)3P(H)Ph (2) and Ph2P(CH2)3P(H)Me (3) have been prepared from Ph2P(CH2)3Cl (1) and NaP(H)Ph or LiP(H)Me, respectively.Metallation of 2 and 3 with n-butyl lithium and further reaction of the lithio-derivatives with one equivalent of 1 yields PhP2 (4) and MeP2 (5).The tritertiary phosphines 4 and 5 have likewise been obtained from RPLi2 (R=Ph, Me) and two equivalents of 1.The synthesis of 4 from PhPCl2 and two equivalents of the Grignard reagent of 1 is also reported.Each of the phosphines 1-5 was characterized by NMR and mass spectroscopy. - Keywords: Secondary-tertiary Diphosphines, Tritertiary Phosphines, Preparation, NMR Spectra, Mass Spectra
- Arpac, Ertugrul,Dahlenburg, Lutz
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p. 146 - 152
(2007/10/02)
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