- Decarboxylative Phosphine Synthesis: Insights into the Catalytic, Autocatalytic, and Inhibitory Roles of Additives and Intermediates
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Phosphines are among the most widely used ligands, catalysts, and reagents. Current synthetic approaches to phosphines are dominated by nucleophilic displacement reactions with organometallic reagents. Here, we report a radical-based approach to phosphines that proceeds by a cross-electrophile coupling of chlorophosphines and redox-active esters. The reaction allows for the synthesis of a broad range of substituted phosphines that were not readily attainable with the present methods. Our experimental and DFT computational studies also clarified the catalytic, autocatalytic, and inhibitory roles of additives and intermediates, as well as the mechanistic details of the photocatalytic and zinc-mediated redox modes that can have implications for the mechanistic interpretation of other cross-electrophile coupling reactions.
- Jin, Shengfei,Haug, Graham C.,Nguyen, Vu T.,Flores-Hansen, Carsten,Arman, Hadi D.,Larionov, Oleg V.
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p. 9764 - 9774
(2019/10/14)
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- Exploring the Reactivity of Donor-Stabilized Phosphenium Cations: Lewis Acid-Catalyzed Reduction of Chlorophosphanes by Silanes
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Phosphane-stabilized phosphenium cations react with silanes to effect either reduction to primary or secondary phosphanes, or formation of P-P bonded species depending upon counteranion. This operates for in situ generated phosphenium cations, allowing catalytic reduction of P(III)-Cl bonds in the absence of strong reducing agents. Anion and substituent dependence studies have allowed insight into the competing mechanisms involved.
- Pearce, Kyle G.,Borys, Andryj M.,Clark, Ewan R.,Shepherd, Helena J.
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supporting information
p. 11530 - 11536
(2018/09/21)
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- Raney-Ni reduction of phosphine sulfides
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A variety of tertiary phosphine sulfides have been reduced by Raney-Ni to give the corresponding phosphineswith high efficiency and undermild conditions. Alkyl, aryl, acyclic, cyclic, aswell as sterically crowded phosphine sulfides are reduced with equal facility. Optically active P-stereogenic phosphine sulfides are reduced stereospecifically with clean retention of configuration at P. Reductions of unsaturated phosphinesulfides is not fully chemoselective and takes place with concomitant partial reduction of the double bond. Clean reduction of the unsaturated phosphine sulfides to the corresponding fully saturated phosphines can be achieved in one step by running the reduction under H2atmosphere (balloon).
- Demchuk, Oleg M.,?wierczyńska, Wioletta,Dziuba, Kamil,Frynas, S?awomir,Flis, Anna,Pietrusiewicz, K. Micha?
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- Reduction of phosphine oxides to the corresponding phosphine derivatives in Mg/Me3SiCl/DMI system
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Direct reductions of phosphine oxides to the corresponding phosphines were performed successfully by using Mg/Me3SiCl/DMI system. The reduction proceeded under mild conditions and was applicable to a wide range of phosphine oxides; triarylphosphine oxides, alkyldiarylphosphine oxides, and dialkylarylphosphine oxides gave the corresponding phosphines in good to excellent yields.
- Kuroboshi, Manabu,Kita, Toshihito,Aono, Asuka,Katagiri, Toshimasa,Kikuchi, Seiya,Yamane, Syoko,Kawakubo, Hiromu,Tanaka, Hideo
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p. 918 - 920
(2015/02/05)
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- Highly efficient reduction of tertiary phosphine oxides and sulfides with amine-assisted aluminum hydrides under mild conditions
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Reduction of tertiary phosphine oxides and sulfides into the corresponding phosphines with amine-assisted aluminum hydrides has been studied. The method is characterized by mild conditions, short reaction time, high efficiency, and expanded substrate scope. The new method is an alternative to the currently used methods of reducing phosphine oxides or recycling phosphines engaged in organic reactions.
- Yang, Shuyan,Han, Xinxin,Luo, Minmin,Gao, Jing,Chu, Wenxiang,Ding, Yuqiang
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p. 1156 - 1160
(2015/06/30)
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- Terminal phosphanido rhodium complexes mediating catalytic P-P and P-C bond formation
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Complexes with terminal phosphanido (M-PR2) functionalities are believed to be crucial intermediates in new catalytic processes involving the formation of P-P and P-C bonds. We showcase here the isolation and characterization of mononuclear phosphanide rhodium complexes ([RhTp(H)-(PR2)L]) that result from the oxidative addition of secondary phosphanes, a reaction that was also explored computationally. These compounds are active catalysts for the dehydrocoupling of PHPh2 to Ph 2P-PPh2. The hydrophosphination of dimethyl maleate and the unactivated olefin ethylene is also reported. Reliable evidence for the prominent role of mononuclear phosphanido rhodium species in these reactions is also provided.
- Geer, Ana M.,Serrano, ngel L.,De Bruin, Bas,Ciriano, Miguel A.,Tejel, Cristina
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supporting information
p. 472 - 475
(2015/02/19)
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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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- CsOH-promoted P-alkylation: A convenient and highly efficient synthesis of tertiary phosphines
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A mild and efficient method for the synthesis of tertiary phosphines and ditertiary phosphines has been developed. In the presence of cesium hydroxide, molecular sieves and DMF at room temperature, various secondary phosphines and alkyl bromides were examined, and the results have demonstrated that this methodology offers a general synthetic procedure to produce tertiary phosphines in moderate to high yields. Optically active tertiary phosphine synthesis is also described.
- Honaker, Matthew T.,Sandefur, Benjamin J.,Hargett, James L.,McDaniel, Alicia L.,Salvatore, Ralph Nicholas
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p. 8373 - 7377
(2007/10/03)
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- Synthesis of 1,2-dihydro-1,3-diaza-2λ5,4λ5-2,4- diphosphorine 2-oxides
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The reaction of lithium (N-diphenylphosphoryl)phosphazenes with nitriles afforded 1,2-dihydro-1,3-diaza-2λ5,4λ5-2,4- diphosphorine 2-oxides through a C-regioselective addition to the cyano linkage followed by in situ cyclocondensation. The new heterocycles were designed to mimic thymine and are promising chemotherapeutic anticancer agents. As an exception, for p-nitrobenzonitrile a SNAr reaction was exclusively observed with the nucleophile entering in the ortho position of the nitro substituent in a process directed by the strong electron withdrawing effect of the NO2 group.
- Andújar, Carmen M,álvarez, Isidro Pérez,Ortiz, Fernando López
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p. 2569 - 2575
(2007/10/03)
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- Stereoselective Synthesis of 1,2,5,6-Tetrahydro 1,3-Oxaza-4-phospha-2-phosphorine 2-Oxides through Reaction of P-Diphenyl(alkyl) (N-diphenylphosphoryl)phosphazenes with Aldehydes and Ketones
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Novel 1,2,5,6-tetrahydro 1,3-oxaza-4-phospha-2-phosphorine 2-oxides have been synthesised stereoselectively through addition of aldehydes and ketones to lithiated (N-diphenylphosphoryl)phosphazenes.
- Perez, Emma Peralta,Ahrens, Birte,Davidson, Matthew G.,Raithby, Paul R.,Teat, Simon J.,Alvarez, Isidro Perez,Ortiz, Fernando Lopez
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p. 275 - 277
(2007/10/03)
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- New synthetic approach to phosphonium salts derived from 4,5-bis(diphenylphosphino)-1-phenylpyridazin-6-one and quantum-chemical calculations of their formation
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4,5-Bis(diphenylphosphino)-1-phenylpyridazin-6-one reacts with ethyl iodide, 1,2-dichloroethane, 1,2-dibromomehtane, and o-dibromobenzene to give the corresponding bis-phosphonium salts which, depending on the halogen derivative, can undergo further trans
- Polezhaeva,Volodina,Prosvirkin,Sakhibullina,Chmutova
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p. 449 - 452
(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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- Alane - A chemoselective way to reduce phosphine oxides
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Phosphine oxides may be chemoselectively reduced to phosphines in excellent yield in the presence of several other functional groups using alane. An aqueous workup is not required.
- Bootle-Wilbraham, Andrew,Head, Steve,Longstaff, James,Wyatt, Paul
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p. 5267 - 5270
(2007/10/03)
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- Alane - A novel way to reduce phosphine oxides
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Phosphine oxides may be reduced to phosphines in excellent yield using alane - AIH3. An aqueous workup is not required.
- Griffin, Sara,Heath, Lucy,Wyatt, Paul
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p. 4405 - 4406
(2007/10/03)
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- Novel Syntheses of Mono- and Bisphosphonated Aromatic Phosphanes by Consecutive Pd-Catalyzed P-C Coupling Reactions and Nucleophilic Phosphanylation - X-ray Structure of Ph2P-C6H4-m-PO3Na2 · 5.5 H2O · iPrOH
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The triphenylphosphane derivatives 2a and 5, bearing one and two phosphonic ester groups, are accessible in high yields by consecutive Pd-catalyzed P-C coupling reactions of p-bromoiodobenzene with Ph2PH and PhPH2, respectively, and then with diethyl phosphite. Ester hydrolysis yields the highly water-soluble sodium salts of mono- and bisphosphonated triphenylphosphane, 3a and 6, respectively. On reaction of the p- and m-fluorophenylphosphonic diethyl esters 7a, 7b with Ph2PK and subsequent ester hydrolysis the isomeric disodium (diphenylphosphano)phenylphosphonates 3a, 3b were obtained. The X-ray structure of Ph2P(C6H4-m-PO3Na2) · 5.5 H2O · iPrOH (space group Cmc21) has been determined. In the solid state, it forms a layer structure with hydrophilic (PO32-, H2O, iPrOH) and hydrophobic (Ph2P) compartments, in which the PO32- anionic groups are not engaged in coordination of the sodium cations.
- Machnitzki, Peter,Nickel, Thomas,Stelzer, Othmar,Landgrafe, Claudia
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p. 1029 - 1034
(2007/10/03)
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- [Cp2ZrHCl](n) A useful reducing agent in phosphorus chemistry
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Selective reductions of P=O, P=S, >C=C2ZrHCl](n) are described, as well as halogen-hydride exchanges.
- Zablocka, Maria,Delest, Bruno,Igau, Alain,Skowronska, Aleksandra,Majoral, Jean-Pierre
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p. 5997 - 6000
(2007/10/03)
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- ZUR REAKTION VON PHOSPHORVERBINDUNGEN MIT SCHWESINGER BASEN-I P-C-BINDUNGKNUEPFUNG AN P-H-FUNKTIONELLEN PHOSPHORVERBINDUNGEN
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Secondary and tertiary phosphines (RR'PH; R2R'P) may be synthesized by alkylation of primary or secondary phosphines with organo halides (R' = Et, n-C7H15, Bz, Me3Si; X = Cl, Br) in the presence of Schwesinger bases as auxillary bases in high yields.Alkylation of diphenylphosphine with alkylene dihalides and Schwesinger bases affords alkylendiphosphines. Key words: Alkylation; secondary and tertiary phosphines; Schwesinger bases.
- Uhlig, Frank,Puschner, Beatrix,Herrmann, Eckhard,Zobel, Bernhard,Bernhardt, Henry,Uhlig, Wolfram
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p. 155 - 164
(2007/10/02)
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- ZUR KENNTNIS DES NATRIUMDIPHENYLPHOSPHINOFORMIATS Ph2PCOONa
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Ph2PCOONa 2, prepared from Ph2PNa and CO2, is readily hydrolyzed in protic media with formation of Ph2PH and CO2.Hydrolysis is much slower in NaOH and small quantities of Ph2P(O)O- and HCOO- are additionally formed.Reactions of 2 with RI in stoichiometrical amounts gave tertiary phosphines Ph2PR (R=Me, Et) while the phosphonium compound I resulted from 2 and MeI in excess.Ph2PCOOMe, Ph2PCOOSiMe3 or Ph2PCSSNa were obtained from 2 and (MeO)2SO2, Me3SiCl or CS2.Ph2P(O)ONa and Ph2P(S)SNa were isolated when 2 was reacted with O2 or S8 in benzene.
- Diemert, Klaus,Hahn, Thomas,Kuchen, Wilhelm
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p. 287 - 294
(2007/10/02)
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- Thermal Stability of Phosphinoacetic Acids
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Phosphinoacetic acids decarboxylate smoothly in toluene solution at 99 deg C and the corresponding alkylphosphine is formed in quantitative yields.Electron-withdrawing substituents at the α position of the carboxylic acid lead to a large increase in the reaction rate.In contrast, electron-withdrawing substituents at the phosphorus atom lead to a small decrease in the rate.We have concluded from the substituent effects, solvent effects, and the influence of bases and acids that both the lone pair of the phosphorus atom and the carboxylate hydrogen atom play a crucial role in the reaction.A mechanism is proposed that proceeds via an ylide.Sodium phosphinocarboxylates do not decarboxylate in an aqueous solution at 95 deg C.Instead a carbon-phosphorus bond cleavage occurs probably by an intramolecular nucleophilic substitution.
- Doorn, Johannes A. van,Meijboom, Nico
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p. 1309 - 1314
(2007/10/02)
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- A FACILE AND EFFICIENT PREPARATION OF THE UNKNOWN PRIMARY β-ENAMINOPHOSPHINES. SYNTHESIS OF THE FIRST 1,3,4-DIAZA-λ5-PHOSPHININES.
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N-Arylphospha-λ5-azenes (1) and (3) were reduced with LiAlH4 to phosphine derivatives.The addition of ethyl azidoformate to β-enaminophosphine (4) followed by heating at 150 deg C yielded 1,3,4-diaza-λ5-phosphinine derivatives (8).
- Barluenga, Jose,Lopez, Fernando,Palacios, Francisco
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p. 2875 - 2878
(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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- Kinetics of Alkaline Hydrolysis of Quaternary Phosphonium Salts. The Influence of Aprotic Solvents on the Hydrolysis of Ethyl(phenyl)phosphonium Iodides.
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Third-order rate constants have been determined for the hydrolyses of the ethyl(phenyl)phosphonium iodides (1) in aqueous methanol and in aqueous tetrahydrofuran.The very large increase in the rate of hydrolysis of tetra- and tri-arylphosphonium salts which is induced by the addition of tetrahydrofuran to the medium drops to almost zero for tetra- and tri-alkylphosphonium salts.This is attributed to an increase in the delocalisation of the positive charge in phosphorus, which leads to less specific solvation of the alkylphosphonium ions.
- Dawber, J. Graham,Tebby, John C.,Waite, Albert A. C.
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p. 1923 - 1926
(2007/10/02)
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- SYNTHESE ET REDUCTION CHIMIQUE DE SELS DE VINYLENE-1,2 ET BUTADIENYLENE-1,4 BIPHOPHONIUMS
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1,2-vinylene- and 1,4-butadienylene-biphosphonium salts with labile groups on phosphorus (e.g. benzyl, 2-cyanoethyl, allyl or benzyl) are synthetized in the reaction of the corresponding tertiary phosphines with acetyl- or vinylacetyl bromide.When the salts are reacted with lithium aluminium hydride and with alkaline alcoholates or cyanides, the unsaturated bridge between the two phosphorus atoms is selectively cleaved to afford one or several tertiary phosphines.For each kind of cleavage a mechanism is proposed and discussed: with alcoholate or cyanide ions, the reaction gives rise to an ethynylphosphonium intermediate which accounts for the formation of the reaction products.
- Cristau, Henri-Jean,Labaudiniere, Lydie,Christol, Henri
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p. 359 - 372
(2007/10/02)
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- SYNTHESIS AND REACTIVITY OF UNSATURATED BIPHOSPHONIUM SALTS
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The synthesis of 1,2 vinylene biphosphonium salts 1 has now benn enlarged to the vinylogous 1,4-butadienylene biphosphonium salts 2.The salts 2, a new class of unsaturated disalts, have also been prepared through a two-step isomerisation of acetylenic sal
- Cristau, Henri-Jean,Duc, Gerald,Labaudiniere, Lydie,Pietrasanta, Francine,Plenat, Francoise
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p. 113 - 116
(2007/10/02)
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