- Synthesis and reactivity of new organophosphorus compounds
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Synthesis of functionally substituted organophosphorus compounds on the basis of reactions of the tri-n-butylphosphine/carbon disulfide, tri-n-butylphosphine/phenyltsothiocyanate, tris(dimethylamino)phosphine/phenylisothiocyanate adducts with a wide range of different dipolarophiles are reported. The development of application of S-Li tri-n-butylphosphonio-dithioformiate derivatives to the synthesis of new types of organophosphorus compounds are reported.
- Tyryshkin, Nickolay I.,Konovalov, Alexander I.,Gavrilov, Viktor V.,Polezhaeva, Nina A.
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- Revealing the Molecular Identity of Defect Sites on PbS Quantum Dot Surfaces with Redox-Active Chemical Probes
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Defects arising on the surfaces of semiconductor quantum dots (QDs) limit the applications of these otherwise promising materials. Efforts to rationally passivate these sites using chemical methods, however, are limited by a lack of molecular-level understanding of surface defects. Herein, we report the application of redox-active chemical probes (E - ′ = -0.48 to -1.9 V vs Fc+/0) coupled with spectroscopic tools (nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), and UV-vis-NIR) to gain insight into the molecular-level nature and reactivity of defects at PbS QD surfaces. First, Pb ion-based traps coordinated by oleate ligands are studied by reaction with outer-sphere reductants, wherein reduction of a subpopulation of Pb2+ ions promotes ligand displacement. We observe a correlation between this reactivity and QD size, wherein minimal ligand displacement occurs in small QDs (2.6 nm) but up to ca. 15% of ligands are displaced with larger QDs (>4 nm). The strength of the reductant also has a significant impact; with QD size held constant, more potent reductants induce a higher extent of ligand displacement than mild reductants. Finally, chalcogenide-based defects (disulfides) are interrogated with selective trialkylphosphine reagents. Comparison of QD reactivity with phosphine probes reveals that large PbS QDs possess a greater proportion of native disulfide defects than small QDs. Collectively, this work yields insight into the identities, likely structural environments and reduction potentials of targeted defect sites, thus providing a detailed picture - and roadmap for passivation - of common QD surface defects.
- Hartley, Carolyn L.,Dempsey, Jillian L.
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- Kinetic study on the reaction of tributylphosphine with methylviologen. Reactivity of the phosphine radical cation intermediate towards nucleophiles
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Tributylphosphine, Bun3P (BP), was reacted with 1.1′-dimethyl-4,4′-bipyridinium (methylviologen; MV2+) in the presence of an alcohol or thiol (RXH; X = O, S) in acetonitrile under an argon atmosphere at 50 °C, which resulted in the gradual formation of the one-electron reduced form of the MV2+, MV+. Meanwhile, BP was oxidized to tributylphosphine oxide (BP-O). The increase in the amount of MV+, which was followed spectrophotometrically with BP and RXH being in large excess, did not obey first-order kinetics. The observation, along with the results from product analysis, shows that single-electron transfer (SET) takes place from BP to MV2+ to generate tributylphosphine radical cation BP·+, as well as MV+, and the resulting BP·+ undergoes ionic reaction with RXH and back electron transfer from MV+ in comparable efficiency. A regression analysis of the kinetic data gave the relative value of the second-order rate constant, kNurel, for the ionic reaction of BP·+ with RXH. Comparison of the kNurel values thus obtained for reactions with various RXH's shows that the reaction of BP·+ with nucleophile RXH is governed by both steric and electronic factors of RXH. The activation energy Ea of the reaction was found to be significantly large, which is in contrast to previous observations that ionic reactions of carbon radical cations with nucleophiles usually have very small values of Ea.
- Yasui, Shinro,Shioji, Kosei,Tsujimoto, Munekazu,Ohno, Atsuyoshi
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Read Online
- Phosphorylation of 3,4-dichloro-5-hydroxy-2(5H)-furanone with tributylphosphine
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The reaction of 3,4-dichloro-5-hydroxy-2(5H)-furanone with 2 mol of tributylphosphine involves substitution of both chlorine atoms to form an unstable diphosphonium salt. The latter undergoes partial hydrolysis with cleavage of one of the P-C bonds, yield
- Polezhaeva,Volodina,Kalinina,Sahibullina,Chmutova,Galkin,Cherkasov
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Read Online
- Reversible Capture and Release of a Ligand Mediated by a Long-Range Relayed Polarity Switch in a Urea Oligomer
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Ethylene-bridged oligoureas characterized by a continuous, switchable chain of hydrogen bonds and carrying a binding site (an N,N′-disubstituted urea) for a hydrogen-bond-Accepting ligand (a phosphine oxide) were synthesized. These oligomers show stronger ligand binding when the binding site is located at the hydrogen-bond-donating terminus than when the same binding site is at the hydrogen-bond-Accepting terminus. An acidic group at the terminus remote from the binding site allows hydrogen bond polarity, and hence ligand binding ability, to be controlled remotely by a deprotonation/reprotonation cycle. Addition of base induces a remote conformational change that is relayed through up to five urea linkages, reducing the ability of the binding site to retain an intermolecular association to its ligand, which is consequently released into solution. Reprotonation returns the polarity of the oligomer to its original directionality, restoring the function of the remote binding site, which consequently recaptures the ligand. This is the first example of a synthetic molecular structure that relays intermolecular binding information, and these dynamic foldamer structures are prototypes of components for chemical systems capable of controlling chemical function from a distance.
- Clayden, Jonathan,Morris, David T. J.,Wales, Steven M.
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supporting information
p. 2841 - 2846
(2022/02/23)
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- The Trityl-Cation Mediated Phosphine Oxides Reduction
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Reduction of phosphine oxides into the corresponding phosphines using PhSiH3 as a reducing agent and Ph3C+[B(C6F5)4]? as an initiator is described. The process is highly efficient, reducing a broad range of secondary and tertiary alkyl and arylphosphines, bearing various functional groups in generally good yields. The reaction is believed to proceed through the generation of a silyl cation, which reaction with the phosphine oxide provides a phosphonium salt, further reduced by the silane to afford the desired phosphine along with siloxanes. (Figure presented.).
- Landais, Yannick,Laye, Claire,Lusseau, Jonathan,Robert, Frédéric
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supporting information
p. 3035 - 3043
(2021/05/10)
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- Application and method for extracting lithium from salt lake brine
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The invention discloses application of an alkylphosphine oxide compound and a method for extracting lithium from salt lake brine, and belongs to the technical field of extraction. An organic phase ofan extraction system for the method comprises the alkylphosphine oxide compound, and the alkylphosphine oxide compound has phosphine oxide groups and is coordinated with Li+ to extract Li+. Compared with the prior art, the extraction method has the characteristics of low cost, simplicity in operation, high extraction efficiency, cleanness, environmental friendliness and the like, and most importantly, the extraction agent can not be hydrolyzed under the extraction condition, can be effectively used for a long time, and has important application value.
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Paragraph 0067-0071
(2021/05/05)
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- Selective C-P(O) Bond Cleavage of Organophosphine Oxides by Sodium
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Sodium exhibits better efficacy and selectivity than Li and K for converting Ph3P(O) to Ph2P(OM). The destiny of PhNa co-generated is disclosed. A series of alkyl halides R4X and aryl halides ArX all react with Ph2P(ONa) to produce the corresponding phosphine oxides in good to excellent yields.
- Zhang, Jian-Qiu,Ikawa, Eiichi,Fujino, Hiroyoshi,Naganawa, Yuki,Nakajima, Yumiko,Han, Li-Biao
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p. 14166 - 14173
(2020/11/13)
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- Cross-linked poly(4-vinylpyridine-N-oxide) as a polymer-supported oxygen atom transfer reagent
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Oxygen atom transfer (OAT) reagents are common in biological and industrial oxidation reactions. While many heterogeneous catalysts have been utilized in OAT reactions, heterogeneous OAT reagents have not been explored. Here, cross-linked poly(4-vinylpyridine-N-oxide), called x-PVP-N-oxide, was tested as a heterogeneous OAT reagent and its oxidation chemistry compared to its molecular counterpart, pyridine-N-oxide. The insoluble oxidant x-PVP-N-oxide demonstrated comparable reactivity to pyridine-N-oxide in direct oxidation reactions of phosphines and phosphites in acetonitrile, but x-PVP-N-oxide did not react in other solvents. The polymer backbone of x-PVP-N-oxide, however, allowed for easy filtering and recycling in sequential oxidation reactions. In addition, x-PVP-N-oxide was tested as the stoichiometric oxidant in a copper-catalyzed OAT reaction to α-diazo-benzeneacetic acid methyl ester. The heterogeneous oxidant was much less reactive than pyridine-N-oxide, indicating that interaction with the metal catalyst was challenging. These results demonstrated a proof-of-concept that recyclable, polymer-supported OAT reagents could be a viable OAT reagents in direct oxidation reactions without metal catalysts.
- Bauer, Anna M.,Ramey, Erin E.,Oberle, Kjersti G.,Fata, Gretchen A.,Hutchison, Chloe D.,Turlington, Christopher R.
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supporting information
(2019/10/02)
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- Single-stage synthesis of alkyl-H-phosphinic acids from elemental phosphorus and alkyl bromides
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Elemental phosphorus (red or white) reacts with alkyl bromides at 60–62 °C in the phase-transfer catalytic system KOH/H2O/PhMe/Et3BnNCl to afford alkyl-H-phosphinic acids in up to 47% yield.
- Gusarova, Nina K.,Sutyrina, Anastasiya O.,Kuimov, Vladimir A.,Malysheva, Svetlana F.,Belogorlova, Natalia A.,Volkov, Pavel A.,Trofimov, Boris A.
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p. 328 - 330
(2019/06/13)
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- The highly selective metal-free oxidation of sulfides, tellurides and phosphines using sodium bromate in the presence of recyclable ionic liquid [bmim]HSO4, at 80°C
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The metal-free oxidation of sulfides to sulfones using sodium bromate (NaBrO3) in [bmim]HSO4:H2O (3:1, v/v) at 80°C is reported. Phenylalkyl, phenylbenzyl, diaryl and heteroaryl sulfides were transformed to the corresponding sulfones. Aryl tellurides and phosphines were oxidised to the corresponding telluroxides and phosphine oxides. All the reactions proceeded smoothly and gave high yields in 20-55 min. The ionic liquid [bmim]HSO4 was easily recovered and recycled.
- Rajeswari,Lumb, Anshika,Khurana, Jitender M.
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p. 442 - 444
(2016/07/21)
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- Aryl group - A leaving group in arylphosphine oxides
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The treatment of triphenylphosphine oxide with organometallic reagents leads to the substitution of up to three phenyl substituents with the incoming carbon nucleophile. The replacement of the phenyl/aryl group in tertiary diarylalkylphosphine oxides or even aryldialkylphosphine oxides was also observed. Naphthyl-substituted phosphine oxides undergo Michael-type addition at the naphthyl group when treated with organolithium reagent.
- Stankevi?, Marek,Pisklak, Jolanta,W?odarczyk, Katarzyna
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p. 810 - 824
(2016/01/20)
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- Oxygen-atom-transfer reactions of a palladium(II) peroxocarbonate complex
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Reactivity of a palladium(II) peroxocarbonate complex was investigated. It was found that a bis(N-heterocyclic carbene) palladium(II) peroxocarbonate acts as an oxygen-atom-transfer (OAT) reagent toward a phosphine and a sulfoxide. In these OAT reactions, the peroxocarbonate was converted to the corresponding palladium(II) carbonate. While the OAT reaction toward triphenylphosphine proceeded only sluggishly, addition of lithium chloride remarkably facilitated the reaction. It was proposed that the chloride ion induces the liberation of the peroxocarbonate moiety from the coordination sphere of palladium.
- Sase, Shohei,Hashimoto, Maki,Goto, Kei
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supporting information
p. 157 - 159
(2015/02/19)
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- Palladium on carbon-catalyzed gentle and quantitative combustion of hydrogen at room temperature
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A quantitative and gentle oxidation (combustion) of hydrogen in the presence of oxygen in a variety of solvents was achieved under palladium on carbon (Pd/C)-catalyzed conditions at ordinary pressures and temperatures. A quantitative generation of water accountable for the consumed oxygen was observed. While hydrogen peroxide (H2O2), which would form as an intermediate, was extremely unstable under the Pd/C-catalyzed conditions to be converted into water with accompanying oxygen generation, the stability of H2O2 was found to be increased in cold (0 °C) trifluoroacetic acid, and the formation of 64% H2O2 based on the consumed oxygen could be detected. A mechanistic elucidation study revealed that the single electron transfer and generation of the hydroxyl radical are involved in the gentle combustion process. The reactive oxygen species generated during the process was effectively utilized for the chemical oxidation of sulfides and phosphines to afford the corresponding sulfoxides and phosphine oxides, respectively.
- Monguchi, Yasunari,Ida, Takashi,Maejima, Toshihide,Yanase, Takayoshi,Sawama, Yoshinari,Sasai, Yasushi,Kondo, Shin-Ichi,Sajiki, Hironao
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supporting information
p. 313 - 318
(2014/05/20)
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- Investigation of non-Rehm-Weller kinetics in the electron transfer from trivalent phosphorus compounds to singlet excited sensitizers
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Singlet excited states (1S* and 1S +*) of neutral and monocationic sensitizers, S and S +, respectively, were quenched by electron transfer (ET) from a variety of trivalent phosphorus compounds (Z3P). The quenching rate constants kq, which are equal to the rate constants kET of the ET from Z3P to 1S* or 1S+*, were determined by the Stern-Volmer method. The logarithm of kET was plotted against free-energy change ΔG0 of the ET. The plot deviated upward from the line predicted by the Rehm-Weller (RW) theory in the endothermic region, the deviation being larger in the ET to a neutral acceptor 1S* than in the ET to a cationic acceptor 1S+*. Such a kinetic behavior is in sharp contrast to that observed in the ET from amines (R 3N), where the ET to either neutral or cationic acceptor takes place according to the RW prediction. The ET from a donor, Z3P or R 3N, to a neutral acceptor 1S* is a charge-separation type, during which electrostatic attraction between the donor and the acceptor is generated, whereas the ET to a cationic acceptor 1S+* is a charge-shift type, which results in neither electrostatic attraction nor repulsion. Difference in kinetics-energetics relationship by the type of ET, which is not recognized in the ET from R3N donor, becomes "visible" when Z 3P is used as a donor. Copyright 2013 John Wiley & Sons, Ltd. The rate constants kET of electron transfer from trivalent phosphorus compounds to singlet photoexcited sensitizers were determined by the Stern-Volmer method. LogkET-ΔG0 plots were found to deviate upward from the line predicted by the Rehm-Weller theory, with deviation being larger in ET to neutral acceptors than in ET to cationic acceptors. Copyright
- Yasui, Shinro,Tsujimoto, Munekazu
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p. 1090 - 1097
(2014/01/06)
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- Synthesis, purification, and characterization of phosphine oxides and their hydrogen peroxide adducts
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Reactions of the tertiary phosphines R3P (R = Me, Bu, Oct, Cy, Ph) with 35% aqueous H2O2 gives the corresponding oxides as the H2O2 adducts R3PO·(H 2O2)x (x = 0.5-1.0). Air oxidation leads to a mixture of products due to the insertion of oxygen into one or more P-C bonds. 31P NMR spectroscopy in solution and in the solid state, as well as IR spectroscopy reveal distinct features of the phosphine oxides as compared to their H2O2 adducts. The single crystal X-ray analyses of Bu3PO and [Cy3PO·(H2O2)] 2 show a PO stacking motif for the phosphine oxide and a cyclic structure, in which the six oxygen atoms exhibit a chair conformation for the dimeric H2O2 adduct. Different methods for the decomposition of the bound H2O2 and the removal of the ensuing strongly adsorbed H2O are evaluated. Treating R 3PO·(H2O2)x with molecular sieves destroys the bound H2O2 safely under mild conditions (room temperature, toluene) within one hour and quantitatively removes the adsorbed H2O from the hygroscopic phosphine oxides within four hours. At 60°C the entire decomposition/drying process is complete within one hour.
- Hilliard, Casie R.,Bhuvanesh, Nattamai,Gladysz, John A.,Bluemel, Janet
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experimental part
p. 1742 - 1754
(2012/03/22)
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- Facile purification of C60O-containing [60]fullerene using trialkylphosphines at room temperature
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A novel method using trialkylphosphines is reported for the facile purification of [60]fullerene containing C60O. When tri-n-butylphosphine and tri-n-octylphosphine were added to unrefined C 60 (ca. 97% purity) in 1,2,4-trimethylbenzene, C60O was readily reduced to give high-purity C60 (>99% purity). The best results were obtained for a high concentration (>1.0 wt %) of unrefined fullerene treated with tri-n-octylphosphine at room temperature. This method is simple and fast in comparison with conventional alumina chromatography, and thus, it is well-suited to industrial-scale separation.
- Hashiguchi, Masahiko,Nagata, Koichi,Tanaka, Katsutomo,Matsuo, Yutaka
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experimental part
p. 643 - 646
(2012/08/07)
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- Effect of electrolysis conditions on the process of anodic oxidation of tertiary phosphines in the presence of camphene
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Anodic oxidation of tertiary phosphines (Et3P, Pr3P, Bu3P, i-Bu3P and Am3P) in the presence of camphene and heterogenic base (trisodium phosphate) on platinum anode in acetonitrile solution of sodium
- Zagumennov, V. A.,Sizova, N. A.
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p. 1368 - 1373,6
(2020/09/16)
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- Nucleophilic activation of a nitrile group: Synthesis of trifluoromethyl substituted 4H-1,3,5-dioxazines
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The negatively charged carbon atom of phosphorus ylides is capable of increasing the nucleophilicity of the triple CN bond. The nitrile group activated in this way can add two equivalents of hexafluoroacetone with the formation of trifluoromethyl substituted 4H-1,2,3-dioxazines. Due to delocalization of the ylidic negative charge one of the C-C bonds acquires a double bond character, the consequence of which is the existence of E/Z-isomerism in these compounds.
- Turcheniuk, Kostiantyn V.,Shevchenko, Igor V.
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experimental part
p. 379 - 382
(2012/03/27)
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- N,N-Dimethyl-S-difluoromethyl-S-phenylsulfoximinium tetrafluoroborate: A versatile electrophilic difluoromethylating reagent
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Over the past decade, sulfur-based fluoromethyl containing compounds have been exhaustively investigated as versatile fluoroalkylating reagents by our research laboratory as well as many others. Lately, we have designed a novel electrophilic difluoromethylating protocol employing in situ prepared N,N-dimethyl-S-difluoromethyl-S-phenylsulfoximinium salt. The present reagent provides excellent reactivity toward a broad spectrum of nucleophilic species (N-, P-, S-, and O-nucleophiles) to yield the corresponding difluoromethylated products with high efficacy under mild conditions. Additional studies have been performed to elucidate the mechanistic fundamentals of the reactions.
- Prakash, G.K. Surya,Zhang, Zhe,Wang, Fang,Ni, Chuanfa,Olah, George A.
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experimental part
p. 792 - 798
(2011/10/09)
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- Basic hydrolysis of 1,4-bis(triphenylphosphonio)buta-1,3-diene dihalides
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Basic hydrolysis of 1,4-bis(triphenylphosphonio)buta-1,3-diene dichloride with 10% NaOH gave isomeric 4-diphenylphosphoryl-4-phenylbut-1(2)-enes and 1-diphenylphosphoryl-1-phenylbuta-1,3-diene, the products of anionotropic migration of a phenyl group from the P atom to the -position. Hydrolysis with Na2CO3 afforded only the diene product. In both cases, triphenylphosphine and triphenylphosphine oxide were isolated as secondary products. Dehydrochlorination of 2-chloro-1,4-bis(triphenylphosphonio) but-2-ene dibromide with triphenylphosphine was proposed as a new convenient route to 1,4-bis(triphenylphosphonio)buta-1,3-diene dibromide.
- Ovakimyan,Pogosyan,Movsisyan,Indzhikyan
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experimental part
p. 560 - 564
(2011/02/17)
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- Thermodynamics of halogen bonding in solution: Substituent, structural, and solvent effects
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A detailed study of the thermodynamics of the halogen-bonding interaction in organic solution is presented. 19F NMR titrations are used to determine association constants for the interactions of a variety of Lewis bases with fluorinated iodoalkanes and iodoarenes. Linear free energy relationships for the halogen bond donor ability of substituted iodoperfluoroarenes XC 6F4I are described, demonstrating that both substituent constants (σ) and calculated molecular electrostatic potential surfaces are useful for constructing such relationships. An electrostatic model is, however, limited in its ability to provide correlation with a more comprehensive data set in which both halogen bond donor and acceptor abilities are varied: the ability of computationally derived binding energies to accurately model such data is elucidated. Solvent effects also reveal limitations of a purely electrostatic depiction of halogen bonding and point to important differences between halogen bonding and hydrogen bonding.
- Sarwar, Mohammed G.,Dragisic, Bojan,Salsberg, Lee J.,Gouliaras, Christina,Taylor, Mark S.
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supporting information; scheme or table
p. 1646 - 1653
(2010/04/04)
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- Electrochemical oxidation of tertiary phosphines in the presence of camphene
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Anodic oxidation of tertiary phosphines (tripropyl-, tributyl-, and triphenylphosphine) in the presence of a bicyclic alkene (camphene) on a platinum and a glassy carbon electrodes was studied. For the first time the voltammetric characteristics of the process of camphene anodic oxidation were obtained. The electrochemical reactions with alkyl and aromatic phosphine were found to be dissimilar. The results of preparative electrooxidation of trialkylphosphines showed that in the course of electrolysis the tertiary phosphine cation-radicals generated on the anode enter into two concurrent reactions: (1) with the parent phosphine to form eventually trialkylphosphonium salts and trialkylphosphine oxides presumably as complex compounds and (2) with camphene to form trialkylcamphenylphosphonium salts and probably phosphonium salts with a monocyclic substituent. Preparative electrochemical oxidation of triphenylphosphine in the presence of camphene affords almost exclusively either triphenylphosphine oxide (in the experiment with platinum anode) or the triphenylphosphine oxide complex with perchloric acid (at the electrolysis on a glassy carbon anode).
- Zagumennov,Sizova,Nikitin
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experimental part
p. 1473 - 1482
(2009/12/04)
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- PROCESS FOR THE PREPARATION OF ALKYLENE GLYCOL
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The invention provides a process for the preparation of an alkylene glycol from an alkylene oxide. Alkylene oxide reacts with carbon dioxide in the presence of a carboxylation catalyst to provide alkylene carbonate; alkylene carbonate reacts with water in the presence of a hydrolysis catalyst to provide alkylene glycol. An initial charge of the carboxylation catalyst and an initial charge of the hydrolysis catalyst are added, the degradation and activity of the hydrolysis catalyst are monitored, and when the activity of the hydrolysis catalyst has fallen below a minimum level, an additional charge of the hydrolysis catalyst is added.
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Page/Page column 4-5
(2009/10/21)
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- A new manifold for the Morita reaction: Diene synthesis from simple aldehydes and acrylates/acrylonitrile mediated by phosphines
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Dienes have been formed with good stereoselectivity and in good yield from simple aldehydes and acrylates/acrylonitrile in the presence of a phosphine and a Lewis acid through a modification of the Morita reaction. The Royal Society of Chemistry.
- Palmelund, Anders,Myers, Eddie L.,Tai, Lik Ren,Tisserand, Steve,Butts, Craig P.,Aggarwal, Varinder K.
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p. 4128 - 4130
(2008/09/16)
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- Electrocatalytic eco-efficient functionalization of white phosphorus
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The novel eco-efficient methods to transform white phosphorus into the esters of phosphoric, phosphorous and phosphonic acids, tertiary phosphines and other organophosphorus compounds under conditions of electrochemical catalysis were elaborated. The mechanism of these processes was investigated using the method of cyclic voltammetry and preparative electrolysis.
- Budnikova, Yulia H.,Yakhvarov, Dmitry G.,Sinyashin, Oleg G.
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p. 2416 - 2425
(2007/10/03)
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- Syntheses and reactions of the bis-boryloxide O(Bpin)2 (pin = O2C2Me4)
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The reaction of the phosphine oxides, OPEt3 1 and OPn-Bu 3 2 with pinacolborane (HBpin) results in phosphine oxide reduction and the formation of O(Bpin)2 3. In contrast, the phosphine oxide OPn-Bu3 reacts with HB(C6F5)2 or B(C6F5)3 to give only the donor-acceptor adducts. Compound 3 reacts with HNPt-Bu3 to give the phosphinimonium borate salt, [t-Bu3PNH2][(Bpin(OBpin)2] 6, while reaction with Cp2ZrMe2 affords the species Cp 2Zr(OBpin)2 7. The Royal Society of Chemistry 2005.
- Hawkeswood, Sarah,Stephan, Douglas W.
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p. 2182 - 2187
(2007/10/03)
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- Bispidine compounds useful in the treatment of cardiac arrythmias
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There is provided compounds of formula I, 1 wherein R1, R2, R3, R4, R5, R6, R7, R41, R42, R43 R44, R45, R46, A and B have meanings given in the description, which are useful in the prophylaxis and in the treatment of arrhythmias, in particular atrial and ventricular arrhythmias.
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- The reaction of N-dichlorophosphoryl-P-trichlorophosphazene with alkyl grignard reagents
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The reactions of N-dichlorophosphoryl-P-trichlorophosphazene Cl3P=N-P(O)Cl2 (1) with benzylmagnesium bromide, 2-phenylethylmagnesium bromide, trimethylsilylmethylmagnesium chloride, n-butylmagnesium bromide, cyclohexylmagnesium bromide, cyclopentylmagnesium bromide, tert-butylmagnesium bromide, iso-propylmagnesium bromide, and ethylmagnesium bromide were studied. Tri- and pentaalkyl phosphazenes were obtained in very poor yield from trimethylsilylmethylmagnesium chloride and cyclohexylmagnesium bromide, respectively. Trialkylphosphoryl compounds formed from benzyl-, 2-phenylethyl-, and n-butylmagnesium bromide. No phosphorus compound could be isolated from the reaction of 1 with t-butyl-, cyclopentyl-, iso-propyl-, and ethylmagnesium bromide.
- Asian,Ozturk,Arslan
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p. 413 - 416
(2007/10/03)
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- PROCESS FOR THE ENANTIOSELECTIVE SYNTHESIS OF PROPARGYL ALCOHOL DERIVATIVES OF R CONFIGURATION FROM THE RACEMIC MIXTURES THEREOF
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The invention relates to a novel process for synthesizing organic compounds of general Formula (I). The said process may be carried out on an industrial scale and makes it possible to obtain from a mixture of racemic alcohols of formula (II), the corresponding chiral alcohols of R configuration, in a high chemical yield.
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Page/Page column 18
(2008/06/13)
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- A new crystalline zwitterionic product from the reaction of Bu3P and DMAD
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Tributylphosphane reacts with DMAD to give the crystalline adduct 2 which is stabilised by extensive delocalisation and whose formation involves an unusual rearrangement. The isomeric structure 7 for the previously reported adduct with triphenylphosphane is supported by 13C NMR spectroscopy. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Aitken, R. Alan,Costello, Stephen J.,Slawin, Alexandra M. Z.,Wilson, Neil J.
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p. 623 - 625
(2007/10/03)
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- Compounds and uses thereof for decreasing activity of hormone-sensitive lipase
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Use of compounds to inhibit hormone-sensitive lipase, pharmaceutical compositions comprising the compounds, methods of treatment employing these compounds and compositions, and novel compounds. The present compounds are inhibitors of hormone-sensitive lipase and may be useful in the treatment and/or prevention of medical disorders where a decreased activity of hormone-sensitive lipase is desirable.
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- The influence of the sacrificial anode nature on the mechanism of electrochemical arylation and alkylation of white phosphorus
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The material of the sacrificial anode has a substantial effect on the nature and yield of the target products of electrochemical phosphorylation of organic halides by white phosphorus in the presence of the nickel complexes with 2,2′-bipyridine. The use of the zinc anode results in the products with tricoordinated phosphorus, viz., triorganylphosphines, the reaction on the aluminum anode affords triorganylphosphine oxides, and the presence of Mg 2+ ions in the reaction mixture provides the transformation of white phosphorus into cyclic phosphines (PhP)5.
- Yakhvarov,Budnikova,Tazeev,Sinyashin
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p. 2059 - 2064
(2007/10/03)
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- A convenient approach for solution-phase synthesis of water-soluble galactoside libraries
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A convenient approach for the solution-phase synthesis of water-soluble galactoside libraries through tributylphosphine promoted reaction of azido compounds with carboxylic acids is described.
- Hong, Feng,Fan, Erkang
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p. 6073 - 6076
(2007/10/03)
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- Peroxo-containing metal complexes having amine oxide, phosphine oxide, arsine oxide, pyridine N-oxide or pyridine ligands as epoxidation catalysts
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PCT No. PCT/EP96/03888 Sec. 371 Date Mar. 11, 1998 Sec. 102(e) Date Mar. 11, 1998 PCT Filed Sep. 4, 1996 PCT Pub. No. WO97/10054 PCT Pub. Date Mar. 20, 1997Olefins can be epoxidized using catalysts I where M is a metal of the 4th to 7th transition group of the Periodic Table of the Elements, L1 is an amine oxide, phosphine oxide, arsine oxide, pyridine N-oxide or pyridine ligand of the formula II, III, VII or VIII, L2 is a customary auxiliary ligand or a further ligand L1 or a free coordination site, X is oxo oxygen or an imido ligand, m is 1 or 2, and n is 1, 2 or 3.
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- Preparation of epoxides from olefins using bis(triorganosilyl) peroxides in the presence of activators based on metallic acid derivatives
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PCT No. PCT/EP97/00982 Sec. 371 Date Sep. 2, 1998 Sec. 102(e) Date Sep. 2, 1998 PCT Filed Feb. 28, 1997 PCT Pub. No. WO97/32867 PCT Pub. Date Sep. 12, 1997Epoxides are prepared from olefins using bis(triorganosilyl) peroxides in the presence of activators based on metalic acid derivatives of the formula where M is a metal of transition groups IV to VII, in particular molybdenum, tungsten or rhenium L is an uncharged ligand selected from the group consisting of amine oxides, phosphine oxides, arsine oxides, phosphoric triamides, formamides and pyridine N-oxides X is an inorganic ligand x is from 1 to 5 y is 0, 1 or 2, Z is 1 or 2 and n is 1 or 2.
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- Quenching of a photosensitized dye through single-electron transfer from trivalent phosphorus compounds
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Various types of trivalent phosphorus compounds 1 undergo single-electron transfer (SET) to the photoexcited state of rhodamine 6G (Rho+(*)) in aqueous acetonitrile to quench the fluorescence from Rho+(*). The rate constants k(p) for the overall SET process were determined by the Stern-Volmer method. The rate is nearly constant at a diffusion-controlled limit in the region of E( 1/2 )(1) +), whereas log k(p) depends linearly on E( 1/2 )(1) in the region of E( 1/2 )(1) > 1.3 V, the slope of the correlation line being -αF/RT with α = 0.2. The potential at which the change in dependence of log k(p) on E( 1/2 )(1) occurs (1.3 V) is in accordance with the value of E( 1/2 )(Rho+(*)) (1.22 V) that has been obtained experimentally. Thus, the SET step is exothermic when E( 1/2 )(1) 1.3 V. The α-value (0.2) obtained in the endothermic region shows that the SET step from 1 to Rho+(*)is irreversible in this region. Trivalent phosphorus radical cation 1(·+) generated in the SET step undergoes an ionic reaction with water in the solvent rapidly enough to make the SET step irreversible. In contrast, the SET from amines 2 and alkoxybenzenes 3 to Rho+(*) is reversible when the SET step is endothermic, meaning that the radical cations 2(·+) and 3(·+) generated in the SET step undergo rapid 'back SET' in the ground state to regenerate 2 and 3.
- Yasui, Shinro,Tsujimoto, Munekazu,Itoh, Kenji,Ohno, Atsuyoshi
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p. 4715 - 4720
(2007/10/03)
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- Stabilization of phosphobetaines that form in the reaction of trialkylphosphines with methoxyallene
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Reactions of tripropyl- and tributylphosphines with methoxyallene were studied. In the case of tripropylphosphine, a mixture of tripropylphosphine oxide and tripropyl-1-formylethylidenephosphorane (the latter in equilibrium with its O-betaine) was obtained. The reaction with tributylphosphine yields, along with tributylphosphine oxide, two homologous ylides, namely, tributyl-1-formylethylidene- and tributyl-1-formylpropylidene-phosphoranes, which are also in equilibria with their O-betaines. A possible scheme of formation of these ylides is discussed.
- Ovakimyan,Minasyan,Petrovskii,Indzkikyan
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p. 1154 - 1156
(2007/10/03)
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- A facile conversion of thio- and selenophosphoric acids and their derivatives into fluoridates by means of reaction with silver fluoride
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Treatment of numerous thio- or selenophosphorus acids with aqueous silver fluoride in CHCl3 at room temperature results in clean formation of the corresponding fluoridates. Analogous results were obtained with other phosphorothio (seleno)ates such as esters, amidates, or halides.
- Chworos, Arkadiusz,Wozniak, Lucyna A.
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p. 9337 - 9340
(2007/10/03)
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- N2O oxidation of phosphines catalyzed by low-valent nickel complexes
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In the presence of a catalytic amount of the nickel(0) complex derived from Ni(acac)2 or NiCl2 with DIBAL or BuLi, nitrous oxide (N2O) was captured and activated to oxidize phosphine(III) into the corresponding phosphine oxide. Bidentate phosphines, for example, 1,3-bis(diphenyl-phosphino)propane (dppp), were employed as effective ligands for N2O; oxidation and were recovered after the reaction.
- Yamada, Tohru,Suzuki, Kyosuke,Hashimoto, Kentaro,Ikeno, Taketo
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p. 1043 - 1044
(2007/10/03)
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- Alkyl migrations in phosphonium compounds with α,β-unsaturated groups
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Alkaline hydrolysis of tributylstyrylphosphonium bromide along with the usual products yields dibutyl(1-butyl-2-phenylethyl)phosphine oxide and 1-phenyl-1-pentene. The results confirm the previously suggested scheme of the reaction of tributylphosphine with phenylacetylene in the presence of water. The reaction of tributylphosphine with diphenylacetylene in the presence of water and also the alkaline hydrolysis of tributyl(phenylethynyl)phosphonium bromide are not accompanied by α-butyl migration. Phosphobetaine formed from tributylphosphine and isopropenylacetylene by the reaction with water transforms into two isomeric phosphine oxides via protonation of β- and δ-carbon atoms. Stereospecific synthesis of E and Z isomers of (diphenyl)(methyl)(2-phenylvinyl)phosphonium bromide is carried out.
- Ovakimyan,Barsegyan,Indzhikyan
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p. 1594 - 1597
(2007/10/03)
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- Pyrazine-based polymeric complex of oxodiperoxochromium (VI) compound as a new stable, mild, efficient and versatile oxidant in organic synthesis
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The title compound was prepared and characterized by conventional methods. Its uses as stoichiometric oxidizing agent for a variety of organic compounds are described. With this reagent alcohols are converted to the corresponding carbonyl compounds. With 1,2-dioles C-C bond cleavage occurs. Decarboxylation of α-hydroxy acids proceeds quantitatively. Also thiols are converted to disulfides, hydroxy phenols to quinones, benzylamines to carbonyl compounds, tertiaryamines to the N-oxides, phosphines to phosphine oxides, sulfides to sulfoxides, and anthracene and phenanthrene to quinones. Deprotection of oximes and oxidative deprotection of silyl ethers proceed easily.
- Tamami, Bahman,Yeganeh, Hamid
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p. 7889 - 7896
(2007/10/03)
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- Dichotomy in the reactivity of trivalent phosphorus compounds Z3P (Z = Ph, nBu, OR) observed in the photoreaction with a ruthenium complex
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Solutions of tris(2,2′-bipyridyl)ruthenium(II) dichloride (Ru2+) and various types of trivalent phosphorus compounds Z3P (Z = Ph, nBu, OR; 1) in methanol have been photolyzed with visible light at 20 °C under an argon atmosphere, resulting in the oxidation of I to the corresponding pentavalent oxo compounds Z3P=O and ligand exchange of Ru2+ with 1. The former process takes place via single-electron transfer (SET) from 1 to Ru2+ in the photoexcited state, Ru2+*, which gene-rates the radical cation intermediate Z3P*+ from 1. The latter results from nucleophilic attack of 1 upon Ru2+*. The results show that 1 can act either as an electron donor or as a nucleo-phile toward Ru2+*. The rate constants for both processes are estimated. An excellent linear correlation is found between the logarithm of the SET rate and the oxidation potential for both the aromatic and aliphatic trivalent phosphorus compounds examined here; the slope of the plot is much less negative than expected on the basis of Rehm-Weller theory. Such behavior in the SET rates is interpreted by comparison with SET quenching by amines. On the other hand, a dualparameter correlation analysis shows that the ligand exchange is regulated by both steric and electronic factors in 1. WILEY-VCH Verlag GmbH, 1997.
- Yasui, Shinro,Tsujimoto, Munekazu,Shioji, Kosei,Ohno, Atsuyoshi
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p. 1699 - 1707
(2007/10/03)
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- Transformation of azido-group to N-(t-butoxycarbonyl)amino group under mild conditions via Staudinger reaction
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In a convenient simple sequence, treatment of azides with tri-n-butylphosphine, followed by addition of di-t-butyl dicarbonate, yields N-(t-Butoxycarbonyl)amines in moderate to good overall yields.
- Afonso, Carlos A. M.
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p. 8857 - 8858
(2007/10/02)
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- THE DEOXYGENATION OF EPOXIDES WITH PHOSPHINES. II. THE FORMATION OF THE SYN-DIMER OF CYCLOBUTADIENE FROM FURAN
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In contrast to the known photochemical reaction of furan with triphenylphosphine (which leads to the anti-dimer of cyclobutadiene and triphenylphosphineoxide) the irradiation of a solution of furan and tri-n-butylphosphine in acetone affords the syn-dimer of cyclobutadiene, together with the corresponding phosphineoxide.
- Condeiu, Cristian,Marton, George,Dinulescu, Ilie G.,Oniciu, Daniela-Carmen,Badea, Florin
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p. 855 - 857
(2007/10/02)
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- Reaction of N-fluoropyridinium salts with Wittig reagents: A novel and convenient approach to symmetric trans-olefins
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N-Fluoropyridinium salts were found to react with Wittig reagents containing electron-withdrawing groups to give olefins in 47-83% yield. The mechanism of this conversion is believed in involve single-electron transfer from Wittig reagent to N-fluoropyridinium cation.
- Kiselyov, Alexander S.
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p. 8951 - 8954
(2007/10/02)
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- SUPERBASE-INDUCED GENERATION OF PHOSPHIDE AND PHOSPHINITE IONS AS APPLIED IN ORGANIC SYNTHESIS
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A series of new direct reactions of red phosphorus (or white) with organyl halides, alkenes and acetylenes have been developed.Reactions occur in superbasic systems, such as alkali metal hydroxide-dipolar aprotic complexing solvent (DMSO, HMPA) or under phase-transfer conditions to afford earlier inaccessible triorganylphosphines and -phosphine oxides including unsaturated ones in good yield.
- Trofimov, B. A.,Gusarova, N. K.,Malysheva, S. F.,Rakhmatulina, T. N.,Voronkov, M. G.,et al.
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p. 271 - 274
(2007/10/02)
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- On the Reaction of N-Vinyliminophosphoranes. Part 11. Convenient Synthesis of 9H-Cycloheptapyridines and Pyridotropones
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Thermal reaction of tributyl(cyclohepta-1,3,5-trienylimino)phosphorane with α,β-unsaturated ketones led to a Michael-type C-C bond formation and subsequent aza-Wittig reaction to give 9H-cycloheptapyridine derivatives in good yields.The 9H-cycloheptapyridine derivatives were oxidized conveniently by t-butyl hydroperoxide in the presence of catalytic chromium trioxide to give two or three isomers of the pyridotropones in good to moderate combined yields.
- Nitta, Makoto,Iino, Yukio
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p. 435 - 440
(2007/10/02)
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- SYNTHESIS AND PROPERTIES OF TRIARYL(DIALKOXYPHOSPHORYLIMIDO)PHOSPHATES
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Phosphoryl- and thiophosphorylimidophosphates were synthesized.These compounds are incapable of imide-amide or imide-imide rearrangements but are cleaved upon prolonged heating at 140-180 deg C to give P-oxides or P-sulfides.
- Tikhonina, N. A.,Khodak, A. A.,Gilyarov, V. A.
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p. 402 - 405
(2007/10/02)
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