- Ready Approach to Organophosphines from ArCl via Selective Cleavage of C-P Bonds by Sodium
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The preparation, application, and reaction mechanism of sodium phosphide R2PNa and other alkali metal phosphides R2PM (M = Li and K) have been studied. R2PNa could be prepared, accurately and selectively, via the reactions of SD (sodium finely dispersed in mineral oil) with phosphinites R2POR′ and chlorophosphines R2PCl. R2PNa could also be prepared from triarylphosphines and diarylphosphines via the selective cleavage of C-P bonds. Na was superior to Li and K for these reactions. R2PNa reacted with a variety of ArCl to efficiently produce R2PAr. ArCl is superior to ArBr and ArI since they only gave low yields of the products. In addition, Ph2PNa is superior to Ph2PLi and Ph2PK since Ph2PLi did not produce the coupling product with PhCl, while Ph2PK only gave a low yield of the product. An electron-withdrawing group on the benzene ring of ArCl greatly accelerated the reactions with R2PNa, while an alkyl group reduced the reactivity. Vinyl chloride and alkyl chlorides RCl also reacted efficiently. While t-BuCl did not produce the corresponding product, admantyl halides could give the corresponding phosphine in high yields. A wide range of phosphines were prepared by this method from the corresponding chlorides. Unsymmetric phosphines could also be conveniently generated in one pot starting from Ph3P. Chiral phosphines were also obtained in good yields from the reactions of menthyl chlorides with R2PNa. Possible mechanistic pathways were given for the reductive cleavage of R3P by sodium generating R2PNa and the substitution reactions of R2PNa with ArCl generating R2PAr.
- Ye, Jingjing,Zhang, Jian-Qiu,Saga, Yuta,Onozawa, Shunya,Kobayashi, Shu,Sato, Kazuhiko,Fukaya, Norihisa,Han, Li-Biao
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p. 2682 - 2694
(2020/07/30)
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- A study on the deoxygenation of trialkyl-, dialkyl-phenyl- and alkyl-diphenyl phosphine oxides by hydrosilanes
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The deoxygenation of 1-alkyl-3-methyl-3-phospholene 1-oxides, which may be regarded as trialkyl phosphine oxides (R3PO), and the reduction of dialkyl-phenylphosphine oxides (R2PhPO) and methyl-diphenylphosphine oxide (MePh2PO) have been elaborated by applying user-friendly silanes, such as tetramethyldisiloxane (>SiH–O–HSin) under solvent-free, catalyst-free, and microwave (MW)-assisted conditions. New silanes of type Ar2SiH2, alkyl2SiH2, and Ar3SiH were also applied in a few cases. The reactivity of the phosphine oxides and the silanes could be mapped on the basis of our experimental data.
- Kovács, Tamara,Urbanics, Anita,Csatlós, Flóra,Keglevich, Gy?rgy
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- Biphilic organophosphorus catalysis: Regioselective reductive transposition of allylic bromides via PIII/PV redox cycling
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We report that a regioselective reductive transposition of primary allylic bromides is catalyzed by a biphilic organophosphorus (phosphetane) catalyst. Spectroscopic evidence supports the formation of a pentacoordinate (σ5-P) hydridophosphorane as a key reactive intermediate. Kinetics experiments and computational modeling are consistent with a unimolecular decomposition of the σ5-P hydridophosphorane via a concerted cyclic transition structure that delivers the observed allylic transposition and completes a novel PIII/PV redox catalytic cycle. These results broaden the growing repertoire of reactions catalyzed within the PIII/PV redox couple and suggest additional opportunities for organophosphorus catalysis in a biphilic mode.
- Reichl, Kyle D.,Dunn, Nicole L.,Fastuca, Nicholas J.,Radosevich, Alexander T.
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supporting information
p. 5292 - 5295
(2015/05/13)
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- Precursor conversion kinetics and the nucleation of cadmium selenide nanocrystals
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The kinetics of cadmium selenide (CdSe) nanocrystal formation was studied using UV-visible absorption spectroscopy integrated with an automated, high-throughput synthesis platform. Reaction of anhydrous cadmium octadecylphosphonate (Cd-ODPA) with alkylphosphine selenides (1, tri-n-octylphosphine selenide; 2, di-n-butylphenylphosphine selenide; 3, n-butyldiphenylphosphine selenide) in recrystallized tri-n-octylphosphine oxide was monitored by following the absorbance of CdSe at λ = 350 nm, where the extinction coefficient is independent of size, and the disappearance of the selenium precursor using {1H}31P NMR spectroscopy. Our results indicate that precursor conversion limits the rate of nanocrystal nucleation and growth. The initial precursor conversion rate (Qo) depends linearly on [1] (Qo(1) = 3.0-36 μM/s) and decreases as the number of aryl groups bound to phosphorus increases (1 > 2 > 3). Changes to Qo influence the final number of nanocrystals and thus control particle size. Using similar methods, we show that changing [ODPA] has a negligible influence on precursor reactivity while increasing the growth rate of nuclei, thereby decreasing the final number of nanocrystals. These results are interpreted in light of a mechanism where the precursors react in an irreversible step that supplies the reaction medium with a solute form of the semiconductor.
- Owen, Jonathan S.,Chan, Emory M.,Liu, Haitao,Alivisatos, A. Paul
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experimental part
p. 18206 - 18213
(2011/03/21)
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- Preparation of diphenyl phosphide and substituted phosphines using alkali metal in silica gel (M-SG)
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Alkali metals absorbed in silica gel (the M-SG reagents) efficiently cleave C-P bonds in triaryl- and diarylphosphines. The resulting alkali metal phosphides can serve as useful building blocks for a variety of phosphines. Alkyldiarylphosphines undergo exclusive aryl group cleavage.
- Nandi, Partha,Dye, James L.,Bentley, Philip,Jackson, James E.
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supporting information; experimental part
p. 1688 - 1692
(2009/09/06)
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- SHOP-type nickel complexes with alkyl substituents on phosphorus, synthesis and catalytic ethylene oligomerization
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The β-keto phosphorus ylides (n-Bu)3P=CHC(O)Ph 6, (t-Bu)2PhP=CHC(O)Ph 7, (t-Bu)Ph2P=CHC(O)Ph 8, (n-Bu) 2PhP=CHC(O)Ph 9, (n-Bu)Ph2P=CHC(O)Ph 10, Me 2PhP=CHC(O)Ph 11 and Ph3P=CHC(O)(o-OMe-C6H 4) 12 have been synthesized in 80-96% yields. The Ni(ii) complexes [N=iPh{Ph2PCHC(O=)(o-OMeC6H4)}(PPh 3)] 13, [N=iPh{Ph(t-Bu)PCHC(O=)Ph}(PPh3)] 15, [N=iPh{(n-Bu)2PCHC(O=)Ph}(PPh3)] 16 and [N=iPh{Ph(n-Bu)PCHC(O=)Ph}(PPh3)] 17 have been prepared by reaction of equimolar amounts of [Ni(COD)2] and PPh3 with the β-keto phosphorus ylides 12 or 8-10, respectively, and characterized by 1H and 31P{1H} NMR spectroscopy. NMR studies and the crystal structure determination of 13 indicated an interaction between the hydrogen atom of the C-H group α to phosphorus and the ether function. The complexes [N=iPh{Ph2PCHC(O=)Ph}(Py)] 18, [N=iPh{Ph(t-Bu)PCHC(O=) Ph}(Py)] 19, [N=iPh{(n-Bu)2PCHC(O=)Ph}(Py)] 20, [N=iPh{Ph(n-Bu) PCHC(O=)Ph}(Py)] 21 and [N=iPh{Me2PCHC(O=)Ph}(Py)] 22 have been isolated from the reactions of [Ni(COD)2] and an excess of pyridine with the β-keto phosphorus ylides Ph3PCH=C(O)Ph 3 or 8-11, respectively, and characterized by 1H and 31P{ 1H} NMR spectroscopy. Ligands 3, 8, 10 and 12 have been used to prepare in situ oligomerization catalysts by reaction with one equiv. of [Ni(COD)2] and PPh3 under an ethylene pressure of 30 or 60 bar. The catalyst prepared in situ from 12, [Ni(COD)2] and PPh 3 was the most active of the series with a TON of 12 700 mol C 2H4 (mol Ni)-1 under 30 bar ethylene. When the β-keto phosphorus ylide 8 was reacted in situ with three equiv. of [Ni(COD)2] and one equiv. of PPh3 under 30 bar of ethylene, ethylene polymerization was observed with a TON of 5500 mol C 2H4 (mol Ni)-1. The Royal Society of Chemistry.
- Kermagoret, Anthony,Braunstein, Pierre
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p. 822 - 831
(2008/09/20)
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- An acidity scale of tetrafluoroborate salts of phosphonium and iron hydride compounds in [D2]dichIoromethane
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Equilibrium constants (K) for reactions between acids and the conjugate base forms of a number of phosphonium salts, [HPR3][BF4], and iron hydrides, [Fe(CO)3H(PR3)2][BF 4], in CD2Cl2 have been determined by means of 31P and 1H NMR spectroscopy at 20°C. The anchor compound chosen for pKCD2Cl2 determinations was [HPCy 3][BF4] with a pKCD2Cl2 value of 9.7, as assigned by literature convention (Cy: cyclohexyl). A continuous scale of pKCD2Cl2 values covering the range from 9.7 to -3 was created and correlated with the ΔH values reported by Angelici and co-workers and literature pKa values. The pKCD2Cl2 values for 15 other hydride or dihydrogen complexes of the iron group elements and of diethyl ether were also placed on this scale. The crystal structures of [Fe(CO) 3H(PCy2Ph)2][BF4] and [Fe(CO) 3(PCy2Ph)2] revealed that the frans-oriented, bulky, unsymmetrical phosphane ligands distort the equatorial plane of the complexes. The acidity of iron carbonyl hydrides is an important feature of the reactions of iron hydrogenase enzymes.
- Li, Tianshu,Lough, Alan J.,Morris, Robert H.
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p. 3796 - 3803
(2008/02/08)
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- Highly atom-economic one-pot formation of three different C-P bonds: General synthesis of acyclic tertiary phosphine sulfides
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The reaction of benzothiadiphosphole 1 with an equimolar mixture of R 1MgBr and R2MgBr gave intermediate A′, which, after only 4-5 min, was treated with an equimolar amount of R3MgBr, giving the asymmetric phosphine PR1R2R3 in 45% overall yield (75-80% yield when R1 = R2 and 85-90% yield when R1 = R2 = R3) and the byproduct 6 in 90% yield. The treatment of 6 with PCl3 quantitatively regenerates the starting reagent 1. Treatment of the phosphines with elemental sulfur gave the corresponding sulfides.
- Baccolini, Graziano,Boga, Carla,Mazzacurati, Marzia
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p. 4774 - 4777
(2007/10/03)
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- An acidity scale for phosphorus-containing compounds including metal hydrides and dihydrogen complexes in THF: Toward the unification of acidity scales
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More than 70 equilibrium constants K between acids and bases, mainly phosphine derivatives, have been measured in tetrahydrofuran (THF) at 20 °C by 1H and/or 31P NMR. The acids were chosen or newly synthesized in order to cover the wide pK(α)(THF) range of 5-41 versus the anchor compound [HPCy3]BPh4 at 9.7. These pK(α)(THF) values are approximations to absolute, free ion pK(a)(THF) and are obtained by crudely correcting the observed K for 1:1 ion-pairing effects by use of the Fuoss equation. The acid/base compounds include 14 phosphonium/phosphine couples, 17 cationic hydride/neutral hydride couples, 9 neutral polyhydride/anionic hydride couples, 14 dihydrogen/hydride couples, and 4 other nitrogen- and phosphorus-based acids. The effects on pK(α) of the counterions BAr'4- and BF4- vs BPh4- and [K(2,2,2-crypt)]+ versus [K(18-crown-6)+ are found to be minor after correcting for differences in inter-ion distances in the ion-pairs involved. Correlations with v(M-H) noted here for the first time suggest that destabilization of M-H bonding in the conjugate base hydride is an important contributor to hydride acidity. It appears that Re-H bonding in the anions [ReH6(PR3)2- is greatly weakened by small increases in the basicity of PR3, resulting in a large increase in the pK(α) of the conjugate acid ReH7(PR3)2. Correlations with other scales allow an estimate of the pK(α)(THF) values of more than 1000 inorganic and organic acids, 20 carbonyl hydride complexes, 46 cationic hydrides complexes, and dihydrogen gas. Therefore, many new acid-base reactions can be predicted and known reactions explained. THF, with its low dielectric constant, disfavors the ionization of neutral acids HA over HB+ and therefore separate lines are found for pK(α)(THF)(HA) and pK(α)(THF)(HB+) when plotted against pK(a)(DMSO) or pK(a)(MeCN). The crystal structure of [Re(H)2(PMe3)5]BPh4 is reported.
- Abdur-Rashid, Kamaluddin,Fong, Tina P.,Greaves, Bronwyn,Gusev, Dmitry G.,Hinman, Justin G.,Landau, Shaun E.,Lough, Alan J.,Morris, Robert H.
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p. 9155 - 9171
(2007/10/03)
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- ELECTROCHEMICAL SYNTHESIS OF TERTIARY PHOSPHINES FROM ORGANIC HALIDES AND CHLOROPHOSPHINES
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The electrochemical synthesis of a wide range of tertiary mono- and diphosphines has been achieved in very simple and mild conditions, in an undivided electrolytic cell with a sacrificial anode of magnesium.
- Folest, J. C.,Nedelec, J. Y.,Perichon, J.
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p. 1885 - 1886
(2007/10/02)
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- A Simple Synthesis and Some Synthetic Applications of Substituted Phosphide and Phosphinite Anions
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Based on data for the acidity relationship of phosphines and phosphinous acids and water in dimethyl sulfoxide and water, a simple method is reported for the generation of phosphide and phosphinite anions by the action of concentrated aqueous alkali on primary and secondary phosphines as well as phosphinous acids in dimethyl sulfoxide or other dipolar aprotic solvents.Alkylation of the anion yields secondary and tertiary phosphines, polyphosphines, functionally substituted phosphines as well as similarly substituted phosphine oxides.Phosphinous acids have beenalkylated in various solvents in two-phase systems containing concentrated aqueous alkali and tetrabutylammonium iodide as phase transfer catalyst.
- Tsvetkov, E. N.,Bondarenko, N. A.,Malakhova, I. G.,Kabachnik, M. I.
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p. 198 - 208
(2007/10/02)
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- On Organophosphorus Compounds, XXII. 1,2-Diaryl-1,2-dibromodiphosphanes
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1,2-Diaryl-1,2-dibromodiphosphanes R(Br)P-P(Br)R 2 (R = C6H5; 4-XC6H4, X = CH3O, F, Cl) were prepared by dehalogenation of RPBr2 with magnesium in a one-batch procedure.While solid 2 presumably consists of only one diastereomer there exists an equilibrium between meso-2, rac-2 and their disproportionation products RPBr2 and (RP)5 in solutions of 2.The influence of temperature, R and solvent on this equilibrium was investigated. - The reaction products of the dissolved phenyl compound 2a correspond to a reaction of its disproportionation products PhPBr2 and (PhP)5, the former preferably reacting on nucleophilic substitution, the latter with electrophilic agents.Under heterogenous conditions diphosphanes Ph(R)P-P(R)Ph can be obtained from 2a and LiR.
- Hinke, Axel,Kuchen, Wilhelm
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p. 3003 - 3010
(2007/10/02)
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- Apparent Molal Volumes of Phosphonium Halides at 15, 25 and 35 deg C
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The densities of aqueous solutions of the phosphonium halides, Bu4-nPhnPX (n = 0-4), some of which were synthesized from the phosphines, were measured at 15, 25 and 35 deg C.Partial molal volumes at infinite dilution, V0 a
- Takaizumi, Katsuko,Wakabayashi, Toshiki
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p. 809 - 818
(2007/10/02)
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- Phosphinegold (I) salts having antiarthritic activity
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The compounds are (pyridine) (trisubstituted phosphine) gold(I) salts which have antiarthritic activity.
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- Tri-substituted phosphinegold(I) 1-thio-β-D-glucopyranosides
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The compounds are tri-substituted phosphinegold(I) 1-thio-β-D-glucopyranosides which have antiarthritic activity and, in particular, are of use in the treatment of rheumatoid arthritis. Of the three substituents on the phosphine one is optionally substituted phenyl and the others are lower alkyl or lower alkoxy.
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