- Synthesis of amorphous carbon materials for lithium secondary batteries
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A new and effective approach to enhance electrochemical properties of amorphous carbons is presented. Phosphorus-doped amorphous carbons have been prepared by incorporating a phosphorus compound into petroleum cokes and carbonizing them at 850°C for 1 h. It was observed that reversible capacity of amorphous carbons was greatly improved by incorporating a very small amount of phosphorus (around 1%), implying that extra lithium-storage-sites were created by phosphorus doping. In addition, the phosphorus-doped amorphous carbons showed outstanding rate capability (205 mA h/g at 5 C) and excellent capacity retention of about 90% after 50 cycles, comparable to that of undoped carbons. Very interestingly, a trade-off relation between capacity and cycle property, which is very common in electrode materials, was not found in the phosphorus-doped amorphous carbons.
- Jeong, Bo Ock,Jeong, Seong Hun,Park, Min-Sik,Kim, Seok,Jung, Yongju
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Read Online
- METHOD FOR PRODUCING PHOSPHOESTER COMPOUND
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PROBLEM TO BE SOLVED: To provide a method whereby, a phosphate compound selected from the group consisting of orthophosphoric acid, phosphonic acid, phosphinic acid, and anhydrides of them is used as raw material and, by one stage reaction, a corresponding phosphoester compound is produced. SOLUTION: To an aqueous solution of a phosphate compound, added is an organic silane or siloxane compound having an alkoxy group or an aryloxy group, and the mixture is subjected to a heating reaction, thereby producing a corresponding phosphoester compound without requiring a catalyst. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT
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Paragraph 0023; 0026-0028
(2021/09/27)
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- Aerobic Oxidation of Phosphite Esters to Phosphate Esters by Using an Ionic-Liquid-Supported Organotelluride Reusable Catalyst
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We describe the synthesis of an ionic-liquid (IL)-supported organotelluride catalyst and its application as a recyclable catalyst for the aerobic oxidation of phosphite esters to phosphate esters. This method shows high conversion rates, allows the ready isolation and purification of the resulting products, and exhibits good reusability of the catalyst.
- Mihoya, Aya,Shibuya, Yuga,Ito, Akane,Toyoda, Anna,Oba, Makoto,Koguchi, Shinichi
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supporting information
p. 2043 - 2045
(2020/11/10)
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- Degradation of tri(2-chloroisopropyl) phosphate by the UV/H2O2 system: Kinetics, mechanisms and toxicity evaluation
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A photodegradation technology based on the combination of ultraviolet radiation with H2O2 (UV/H2O2) for degrading tri(chloroisopropyl) phosphate (TCPP) was developed. In ultrapure water, a pseudo-first order reaction was observed, and the degradation rate constant reached 0.0035 min?1 (R2 = 0.9871) for 5 mg L?1 TCPP using 250 W UV light irradiation with 50 mg L?1 H2O2. In detail, the yield rates of Cl? and PO43? reached 0.19 mg L?1 and 0.58 mg L?1, respectively. The total organic carbon (TOC) removal rate was 43.02%. The pH value of the TCPP solution after the reaction was 3.46. The mass spectrometric detection data showed a partial transformation of TCPP into a series of hydroxylated and dechlorinated products. Based on the luminescent bacteria experimental data, the toxicity of TCPP products increased obviously as the reaction proceeded. In conclusion, degradation of high concentration TCPP in UV/H2O2 systems may result in more toxic substances, but its potential application for real wastewater is promising in the future after appropriate optimization, domestication and evaluation.
- He, Huan,Ji, Qiuyi,Gao, Zhanqi,Yang, Shaogui,Sun, Cheng,Li, Shiyin,Zhang, Limin
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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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- Hydrophosphonylation of Alkynes with Trialkyl Phosphites Catalyzed by Nickel
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The use of simple and inexpensive NiCl2?6 H2O as a catalyst precursor for C?P bond formation in the presence of commercially available trialkyl phosphites (P(OR)3, R=Et, iPr, Bu, SiMe3) along with several alkynes is presented. Control experiments showed the in situ formation of (RO)2P(O)H as the species that undergo the addition into the C≡C bond at the alkynes to yield the product of P?H addition. The hydrophosphonylation of diphenylacetylene with P(OEt)3, P(OiPr)3, and P(OSiMe3)3 proceeds in high yields (>92 %) without the need of a specific solvent or ligand. This method is useful for the preparation of organophosphonates for both phenylacetylene as a terminal alkyne model and internal alkynes in yields that range from good to modest.
- Islas, Rosa E.,García, Juventino J.
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p. 4125 - 4131
(2017/10/09)
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- Method of synthesizing alkyl phosphate
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The invention relates to a method of synthesizing alkyl phosphate. The method includes: in the process of synthesizing alkyl phosphate, using inert substance to mix with reactant alcohol; dropwise adding phosphorus oxychloride at low temperature, allowing reaction at normal temperature for a period of time, and rising temperature for reaction; using alkali for neutralizing, washing with water, and distilling to remove low-boiling-point solvent and reactant; depressurizing and distilling to obtain high-purity alkyl phosphate. Due to existence of the third inert substance, reaction is enabled to be milder, and high yield is realized; a lot of generated hydrogen chloride is removed in a gaseous mode, so that alkali consumption is reduced and production cost is lowered.
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Paragraph 0048; 0049
(2017/01/02)
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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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- METHOD OF THE SYNTHESIS OF DIALKYL HALOALKYLPHOSPHONATES AND DIALKYL HALOALKYLOXYALKYLPHOSPHONATES
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The invention deals with the method of the synthesis of dialkyl haloalkylphosphonates and dialkyl haloalkyloxyalkylphosphonates via a microwave-heated Michaelis-Arbuzov reaction of trialkylphosphites with dihaloalkanes or bis(haloalkyl)ethers in a closed vessel, during which the reaction mixture, containing a dihaloalkane or bis(haloalkyl)ether and a trialkylphosphite, is heated with microwave radiation with the standard frequency (2.45 GHz) to reach a reaction temperature which is specific for each individual halogen. In the subsequent reaction of the first dihaloalkane or bis(haloalkyl)ether halogen atom with trialkyl phosphite, the desired dialkyl haloalkylphosphonate or dialkyl haloalkyloxyalkylphosphonate is formed, but the reaction of its halogen atom with the so-far present trialkylphosphite, leading to the creation of the relevant bisphosphonate, no longer takes place. In the case of an inhomogeneous reaction mixture, also the desired product in the amount of 0.1-5 molar % is added to the reaction mixture for its homogenization, which homogenizes it and thus precludes its uncontrollable overheating. The entire process of synthesis is more effective, faster, less expensive and more environmentally friendly than the methods described so far in the literature. The possibility of performing the described procedure also in a continuous-flow microwave reactor allows industrial production with minimal demands on an optimization of the reaction conditions for larger quantities, eliminates some security risks, dramatically reduces the spatial demands in production and reduces the need for the usage of large-tonnage industrial reactors.
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Page/Page column 19-20
(2012/02/13)
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- Efficient and 'green' microwave-assisted synthesis of haloalkylphosphonates via the Michaelis-Arbuzov reaction
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This paper deals with a novel, efficient and environmentally friendly synthesis of dialkyl haloalkylphosphonates via a microwave-assisted Michaelis-Arbuzov reaction. The approach is solventless, requires only one equivalent of each of the starting compounds, and provides high yields of pure products from which the impurities are easy to remove. The process has been optimised for batch and flow reactors and is especially profitable for the production of key intermediates in synthesis of Ethephon or acyclic nucleoside phosphonates such as adefovir, tenofovir, and cidofovir. The Royal Society of Chemistry.
- Jansa, Petr,Holy, Antonin,Dracinsky, Martin,Baszczynski, Ondrej,Cesnek, Michal,Janeba, Zlatko
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supporting information; experimental part
p. 882 - 888
(2011/06/20)
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- The role of structural effects on the reactions of alkoxyl radicals with trialkyl and triaryl phosphites. A time-resolved kinetic study
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(Figure presented) A time-resolved kinetic study on the reactions of alkoxyl radicals with trialkyl and triaryl phosphites ((RO)3P: R = Me, Et, i-Pr, t-Bu; (ArO)3P: Ar = C6H5, 2,4-(t-Bu)2C6H3) has been carried out. In the (RO)3P series, the alkoxyl radicals (cumyloxyl (CumO ·) and benzyloxyl (BnO·)) undergo addition to the phosphorus center with formation of intermediate tetraalkoxyphosphoranyl radicals (R′OP·(OR)3: R = Me, Et, i-Pr, t-Bu; R′ = Bn, Cum). The addition rate constants are influenced by steric effects, decreasing on going from R = Me to R = t-Bu and from BnO · to CumO·. Rate constants for β-scission of the phosphoranyl radicals R′OP·(OR) 3 have also been determined, increasing, for a given alkyl group R, in the order R′ = tert-butyl · reacts with triaryl phosphites (ArO) 3P to give phenoxyl radicals, with rate constants that are influenced to a limited extent by substitution of the aromatic rings. The radical scavenging ability of these substrates is briefly discussed.
- Bietti, Massimo,Calcagni, Alessandra,Salamone, Michela
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scheme or table
p. 4514 - 4520
(2010/10/02)
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- Preparation of halohydrocarbyl phosphonic acid diesters
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In a process for the production of halohydrocarbyl phosphonic acid diesters via a Michaelis-Arbuzov type reaction which results in high conversion and selectivity of product with ease of purification; the improvement comprises reacting hydrocarbyl halide with trihdydrocarbyl phosphite in a molar ratio of about 6:1 and in the presence of an effective amount of a polarity lowering additive.
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Page/Page column 5-6
(2008/06/13)
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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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- Reactivity of diacyloxyiodobenzenes toward trivalent phosphorus nucleophiles
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The reaction of diacyloxyiodobenzenes and tetravalent phosphorus nucleophiles was investigated. It was established that both H-phosphonates and secondary phosphine oxides react with diacetoxyiodobenzene in alcohols in the presence of sodium alcoholates yi
- Makowiec, Slawomir,Rachon, Janusz
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p. 352 - 359
(2007/10/03)
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- Irreversibility of single electron transfer occurring from trivalent phosphorus compounds to iron(III) complexes in the presence of ethanol
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Various types of trivalent phosphorus compounds (1; Ph(3-n)P(OR)n) underwent single electron transfer (SET) to unsubstituted (2H) and 5-chloro-substituted tris(1, 10-phenanthroline)iron(III) complexes (2Cl) in the presence of ethanol in acetonitrile, resulting in the reduction of 2 to the corresponding iron(II) complexes. The rate constants (kp) for the overall SET process were determined spectrophotometrically to show that within each series of 1 with an identical alkoxy group OR, log kp correlates linearly with the difference in the half-wave potentials (ΔE1/2) between 1 and 2. The slope of each correlation line gave an α-value for each series of 1. The α-values were significantly smaller than unity, indicating that the SET step is irreversible, even though this step is endothermic. The trivalent phosphorus radical cation 1.+ generated in the SET step undergoes a rapid ionic reaction with ethanol, which is certainly the origin of the irreversibility. Upon examining the α-values more closely, it was found that the transition state of the SET step becomes earlier with increasing bulkiness of the substituent OR. It is concluded that 1 and 2 form a tight encounter complex to undergo SET from the former to the latter.
- Yasui, Shinro,Itoh, Kenji,Tsujimoto, Munekazu,Ohno, Atsuyoshi
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p. 1311 - 1318
(2007/10/03)
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- The reactions of dialkyl phosphites and phosphine oxides with iodosylbenzene
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The reaction of iodosylbenzene with > P(O)H type of acids (dialkyl phosphites, secondary phosphine oxides) was studied. The acids of >P(O)H type add to iodosylbenzene to yield intermediate 6 which in the aprotic solvents yields oxidation products, it means >P(O)OH acids and/or anhydride of >P(O)OP(O) P(O)OR ester is the major product.
- Makowiec, Slawomir,Rachon, Janusz
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p. 941 - 955
(2007/10/03)
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- Chlorine free synthesis of organophosphorus compounds based on the functionalization of white phosphorus (P4)
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Oxidative alkoxylations of P4 in toluene-alcohol solutions are studied. These reactions need oxygen, a catalyst (PdCl2, RuOHCl3, RuCl3) and a co-oxidant (CuCl2, NaNO2, FeCl3, 1,4-benzoquinone, NaBrO3). Trialkylphosphates (RO)3P(O) and dialkylphosphites (RO)2P(O)H are the major products of the reaction. Kinetic experiments concerning the rate of absorption of O2 during these reactions are also reported.
- Abdreimova, Rumiya R.,Akbayeva, Dina N.,Polimbetova, Gulshara S.,Caminade, Anne-Marie,Majoral, Jean-Pierre
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p. 239 - 254
(2007/10/03)
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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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- Absolute viscosity and density of trisubstituted phosphoric esters
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This paper presents measurements on the absolute viscosity (η) and density (ρ) of trisubstituted phosphoric esters which are useful in understanding their flow mechanism necessary for accessing their role as plasticizers. The effect of chain length and branching has been examined on the η and ρ trends. From η data, by using the Vogel-Tammann-Fulchur (VTF) equation, the VTF temperature (To) has been obtained which also represents the ideal glass transition temperature. To is related to the flexibility of the molecules. It is observed that To initially decreases with molecular weight, reaches a minimum, and increases thereafter. The initial decrease in To has been attributed to the enhanced flexibility of the phosphate esters. Reversal of flexibility with relative molar mass beyond 400 is due to the gentle collision of the arms of the trisubstituted phosphoric esters. This has been further corroborated from the molar mass exponent as exhibited in the η-molar mass plot. The isomeric effect on η has also been investigated in tricresyl phosphates, hitherto for the first time. The ortho isomer has highest η among the isomers. The para isomer was found to have lowest To and hence highest flexibility compared to the ortho and meta isomers.
- Kannan,Kishore
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p. 649 - 655
(2007/10/03)
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- Interaction between trialkyl phosphites and aminoxyl radicals: A model study for polymer stabilization
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2,2,6,6-Tetramethylpipendine-1-oxyl (TEMPO) and its bis-1-oxyl analogue react with methyl and triisopropyl phosphite forming tetramethylpiperidine phosphite which is the main product of the reaction together with dialkyl phosphates. Minor products are tetramethylpiperidinyldialkyl phosphate and tetramethylpiperidine. The reaction mechanism was elucidated by observing the intermediate formation of the phosphoranyl radical which evolves forming the isolated products. The rate of this reaction is considerably lower compared to the stabilization reaction observed between phosphites and hydroperoxides during polymer oxidation. Thus the former reaction could be considered negligible in terms of polymer stabilization under the conditions studied.
- Mar'in, Alexander,Damiani, Elisabetta,Canestrari, Stefania,Dubs, Paul,Greci, Lucedio
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p. 1363 - 1367
(2007/10/03)
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- Synthesis of Trialkyl Phosphates from White Phosphorus
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A new method was proposed for preparing trialkyl phosphates directly from white phosphorus by its electrolysis in a mixture of acetonitrile, alcohol, and water with tetraethylammonium iodide as supporting electrolyte. To increase the amount of the product synthesized in the unit volume of the electrolyte solution and the productivity of the process, phosphorus and water are added to the electrolyte in portions, which allows synthesis of up to 1 mol of trialkyl phosphate in 1 1 of the electrolyte solution.
- Romakhin,Nikitin
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p. 1023 - 1026
(2007/10/03)
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- Reaction of trivalent phosphorus compounds with an Fe(III) complex in the presence of alcohol. Single electron transfer accompanied by a P-O bond formation
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Reactions of various types of trivalent phosphorus compounds with iron(III) complex in the presence of ethanol have been examined kinetically, showing that the single electron transfer from the former compounds to the latter is followed by rapid reaction of the resulting trivalent phosphorus radical cations with ethanol.
- Yasui, Shinro,Itoh, Kenji,Tsujimoto, Munekazu,Ohno, Atsuyoshi
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p. 1019 - 1020
(2007/10/03)
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- Optimization of 2-chloroethylphosphonic acid synthesis by acid hydrolysis of dialkyl-2-chloroethylphosphonate compounds. Influence of the nature of alkyl phosphonate functions
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2-Chloroethylphosphonic acid (ethephon) 1 is very much used in agriculture as a plant regulator.It is an especially good stimulant used to increase the latex production of Hevea brasiliensis.Ethephon is generally obtained by HCl hydrolysis of bis(2-chloroethyl)-2-chloroethylphosphonate, previously prepared by Arbuzov rearrangement of tri(2-chloroethyl)phosphite.However, because of the low reactivity of 2-chloroethylphosphonate functions towards acid hydrolysis, this synthetic way is not convenient to prepare pure 2-chloroethylphosphonic acid with high yields.The present purpose was to study the hydrolysis of various dialkyl-2-chloroethylphosphonates in view to define an efficient synthetic protocol, leading to very pure crystallized ethephon with high yields. - Keywords: 2-chloroethylphosphonic acid; ethephon; dialkyl-2-chloroethylphosphonate; Arbuzov reaction; trialkyl phosphite; acid hydrolysis
- Cauret, Laurent,Brosse, Jean-Claude,Derouet, Daniel,Livonniere, Hugues De
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p. 463 - 470
(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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- Electrochemical Oxidation of Metal Dialkyl Phosphites and Their Reaction with Halogens
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Electrochemical oxidation of sodium dialkyl phosphites with alkyl radicals of normal structure leads to formation of tetraalkyl pyrophosphites as the main products, while electrochemical oxidation of litium dialkyl phosphites and sodium salts with branched alkyl radicals yields tetraalkyl hypophosphates. The reaction of metal dialkyl phosphites with halogens leads to analogous results.
- Romakhin,Zagumennov,Nikitin
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p. 1022 - 1026
(2007/10/03)
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- Oxidative P-O and P-C Coupling of Butanol with Phosphine in the Presence of Oxidizers and Platinum(IV) and Platinum(II)
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A butanol solution of Na2PtCl6 at 60-80°C in the presence of p-benzoquinone or NaBrO3 is found to rapidly consume even traces of PH3 until complete reduction of benzoquinone to hydroquinone or NaBrO3 to NaBr, respectively. The nature of products depends on the valence state of platinum and the nature of the oxidizer. Without an oxidizer, platinum(IV) is reduced to platinum(II) with formation of tributyl phosphate, the product of P-O coupling of PH3 with BuOH, while platinum(II) is reduced to platinum(0) with formation of butylbis(α-hydroxybutyl)phosphine oxide Bu(α-PrCHOH)2PO, the product of P-C coupling of PH3 with BuOH. In the presence of benzoquinone, which oxidizes Pt(0) to Pt(II), a P-C bond is formed, while in the presence of sodium bromate, which regenerates Pt(II) to Pt(IV), P-O coupling of PH3 with BuOH occurs. The products and principal steps of this new reaction were studied by the methods kinetics, red-ox potentiometry, chemical modeling, inhibition of free-radical reactions, 31P NMR, IR and X-ray photoelectron spectroscopy, X-ray spectral microanalysis, and gas-liquid chromatography. We showed that the P-C coupling of PH3 with BuOH is promoted by platinum(II) complex, while P-O coupling is promoted by platinum(IV) complex. In the key steps the Pt(II) butoxyphosphide complex PtCl3(OBu)(PH2)- arises from reaction of the Pt(II) phosphide complex with platinum(IV). The red-ox decomposition of intermediate complexes leads to formation of phosphinite (BuO)2PH2 and Pt(II), or (α-hydroxybutyl)phosphine and Pt(0). The catalytic cycles are completed by fast steps of oxidative butoxylation of (BuO)PH2 to (BuO)3PO or by α-hydroxybutylation of (PrCHOH)PH2 to Bu(PrCHOH)2PO, and oxidation of Pt(II) to Pt(IV) with bromate or Pt(0) to Pt(II) with benzoquinone, respectively.
- Dorfman,Polimbetova,Aibasov
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p. 231 - 247
(2007/10/03)
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- α-HALOGENO SULPHOXIDES AS AMBIDENT ELECTROPHILES TOWARDS DIALKYL PHOSPHITE ANIONS
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α-Halogenomethyl alkyl(aryl) sulphoxides have been found to undergo nucleophilic attack by dialkyl phosphite anions at the α-carbon atom and/or at halogen.
- Mikolajczyk, Marian,Zatorski, Andrzej
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p. 323 - 324
(2007/10/02)
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- Electrosynthesis of aliphatic esters of phosphorus acids from white phosphorus in alcohol solutions, involving radical cations of phenothiazine and triarylamine
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Aliphatic esters of phosphorus acids can be prepared from white phosphorus by electrolysis of emulsified white phosphorus in alcohol solutions of phenothiazine or triarylamine.
- Budnikova, Yu. G.,Kargin, Yu. M.
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p. 504 - 507
(2007/10/03)
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- Synthesis of dialkyl phosphites and trialkyl phosphates by oxidation of sodium hypophosphite by copper(II) chloride
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Sodium hypophosphite oxidazies in alcoholic solution of CuCl2 at 50-80 deg C to give dialkyl phosphite and trialkyl phosphate.The yield of trialkyl phosphate increases with decreasing molecular weight of the alcohol and reaches ca. 100percent for MeOH and EtOH.The optimal conditions were found, and the mechanism of oxidation of NaPH2O2 to (RO)2PHO and (RO)3PO by copper(II) chloride was studied.The reaction proceeds via the formation of alkyl hypophosphite and copper(II) complexes with alkyl hypophosphite and dialkyl phosphite, which undergo inner-sphere two-electron redox decomposition with the liberation of dialkyl phosphite and trialkyl phosphate, respectively.
- Dorfman, Ya. A.,Aleshkova. M. M.
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p. 515 - 520
(2007/10/03)
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- THE KINETICS AND MECHANISM OF THE REACTION OF TRICO-ORDINATE PHOSPHORUS COMPOUNDS WITH TETRACYANOQUINODIMETHANE AND TETRACYANOETHYLENE
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Trico-ordinate phosphorus compounds, ArnP(OPri)3-n where n = 0-3, react with tetracyanoquinodimethane (TCNQ) in acetonitrile in the presence of water to give the corresponding phosphoryl compounds, ArnP(O)(OPri)3-n and 1,4-bis-dicyanomethylbenzene (TCNQH2) in quantitative yield.The kinetics of these reactions are reported together with the Hammett ρ-parameters from variation of substituents in the aryl group for n = 1,2 and 3.On the basis of the available evidence, a mechanism is proposed involving one electron transfer from phosphorus (the donor) to TCNQ.A kinetic study of the reaction of triarylphosphines with TCNE in aqueous acetonitrile, however, suggests rate-limiting nucleophilic attack on nitrogen rather than the radical cation mechanism.Key words: Tricoordinate phosphorus, tetracyanoquinodimethane, tetracyanoethylene, kinetics, mechanism.
- Hall, C. D.,Beer, P. D.,Powell, R. L.,Naan, M. P.
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p. 145 - 156
(2007/10/02)
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- Direct Transformation of Trialkyl Phosphates into Organolithium Compounds by a DTBB-Catalysed Lithiation
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The reaction of different alkylic or phenylic phosphates 1 with an excess of lithium powder and a catalytic amount of DTBB (5 mol percent) in the presence of an electrophile -Barbier-type reaction conditions- in THF at -30 deg C leads to the formation of the expected products 2, resulting from the reaction of the in situ generated organolithium compound with the corresponding electrophile.
- Guijarro, David,Mancheno, Balbino,Yus, Miguel
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p. 8551 - 8558
(2007/10/02)
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- ELECTROCHEMICALLY INDUCED PROCESSES OF FORMATION OF PHOSPHORIC ACID DERIVATIVES. 3. ELECTROSYNTHESIS FROM WHITE PHOSPHORUS IN ALCOHOL-WATER SOLUTIONS
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It has been established that the process of splitting of the P-P bonds of the white phosphorus molecules is initiated by cathode-generated nucleophiles (HO-, RO-), while functionalization of the P-H bond formed in phosphoric oligomers occurs under the action only of alcohol.The primary product after splitting of all the P-P bonds in phosphoric oligomers is dialkylphosphite (in alcohol-water media), or trialkylphosphite (in absolute alcohol), in the course of electrolysis being transformed into trialkylphosphate.Formation of esters of pyrophosphoric acid with reduced protogenic character of the medium was examined.It is proposed that under these conditions nucleophilic reagents of the type (>P)c-O- form and participate in splitting of the P-P bonds. Keywords: phosphoric acid derivatives, white phosphorus, electrosynthesis, alcohol-water solution.
- Budnikova, Yu. G.,Kargin, Yu. M.,Zaripov, I. M.,Romakhin, A. S.,Ignat'ev, Yu. A.,et al.
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p. 1580 - 1584
(2007/10/02)
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- The Kinetics and Mechanism of the Reaction of Tricoordinate Phosphorus Compounds with Diaryl Trisulfides
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Kinetic data and activation parameters are reported for the reaction of a series of tricoordinate phosphorus compounds, , with diaryl trisulfides.The second-order rate coefficients for series of arylphosphines, phosphinites and phosphonites, correlate with the Hammett ? constants of the aryl substituents with ρ values of -1.1, -1.1 and -1.1 respectively and these results are discussed in terms of a biphilic mechanism analogous to that proposed for the reaction of tricoordinate phosphorus with S8.
- Hall, C. Dennis,Tweedy, Bruce R.,Kayhanian, Robert,Lloyd, John R.
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p. 775 - 779
(2007/10/02)
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- Palladium-catalyzed preparation of dialkyl allylphosphonates. A new preparation of diethyl 2-oxoethylphosphonate
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Palladium-catalyzed Michaelis-Arbuzov reaction of allyl acetates with trialkyl phosphites affords dialkyl allylphosphonates. Diethyl 2-oxoethylphosphonate is efficiently prepared by ozonization of diethyl allylphosphonate.
- Malet,Moreno-Manas,Pleixats
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p. 2219 - 2228
(2007/10/02)
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- Photoinduced single electron transfer activation of organophosphines: Nucleophilic trapping of phosphine radical cation
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Photophysical studies show that organophosphines (1-4) form charge transfer stabilized exciplex with excited singlet 1DCN*. One electron oxidation of phosphines to corresponding radical cation via phosphine... 1DCN* electron donor, acceptor pair dissociation is reported. Phosphine radical cations are lound to react readily with moisture to give phosphine oxides.
- Pandey, Ganesh,Pooranchand, Dinah,Bhalerao
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p. 1745 - 1752
(2007/10/02)
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- Organophosphorus Antioxidants. X. The Hydroperoxide Decomposing Action of Phosphites, Phosphonites and Thiophosphites
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The kinetics and mechanism of reactions of phosphites, phosphonites, thiophosphites and hydrogenphosphites with cumyl (CHP), t-butyl (TBHP) and α-tetralyl (THP) hydrogenperoxides has been studied by means of (31)P-n.m.r. spectroscopy, high performance liquid chromatography and iodometric titration.All three valent phosphorus compounds studied initially react with hydroperoxides stoichiometrically to give the corresponding P=O products and alcohol.Some species are able to decompose cumyl hydroperoxide catalytically to form phenol and aceton.Acyloin phosphites decompose CHP catalytically after a stoichiometric reaction as thiophosphites do.Tetramethylpiperidinyl phosphites ("HALS-phosphites") react with hydroperoxides only stoichiometrically but with high velocity.Phosphonites react with hydroperoxides in the same way as the corresponding phosphites.Their reactivity, however, is much higher.Hydrogenphosphites are less reactive than phosphites in the reaction with hydroperoxides.They are able to act catalytically.
- Koenig, T.,Habicher, W. D.,Schwetlick, K.
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p. 913 - 922
(2007/10/02)
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- Reaktionen trivalenter Phosphorverbindungen mit tert-Butoxylradikalen
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The products of the reaction of several alkyl, aryl, sterically hindered aryl and cyclic phosphites, thiophosphites, benzenephosphonites and triphenylphosphine with tert-butoxyl radicals generated by thermolysis of di-tert-butyl peroxalate (DTBPO) in chlorobenzene at 50 deg C was studied. Alkyl phosphites are oxidized to the corresponding phosphates by β-scission of the intermediate phosphoranyl radicals.Phenyl phosphites react under displacement of a phenoxyl to give tert-butyl phosphites by α-scission of the intermediate phosphoranyl radicals.Sterically hindered p-methyl-phenyl phosphites also form the tert-butyl phosphites accompanied by rearranged p-hydroxyphenylmethanephosphonates.Cyclic arylene phosphites are predominantly oxidized, substitution takes place to a minor extent. Benzenephosphonites and phosphines react with tert-butoxyl radicals by oxidation to give the corresponding phosphonates and phosphine oxide, resp. Those phosphorus compounds which are oxidized with the formation of tert-butyl radicals accelerate the thermal decomposition of DTBPO under the condition studied.
- Schwetlick, Klaus,Koenig, Thomas,Rueger, Claus,Pionteck, Juergen
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p. 360 - 366
(2007/10/02)
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- A Duality of Mechanism in the Hydrolysis of Acyclic Phosphoranes
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Acyclic phosphoranes, ArnP(OR)5-n with n=0-3 are shown to hydrolyse in neutral conditions by SN1 (P) mechanism for n=1,2, and 3 but by an SN2 (P) or addition-elimination mechanism for n=0; this is analogous to the classical SN1 vs.SN2 mechanisms observed for solvolysis reactions at tetrahedral carbon.
- Lowther, Nicholas,Hall, C. Dennis
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p. 1303 - 1305
(2007/10/02)
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- REACTIONS OF PHOSPHITES WITH TRICHLOROACETONITRILE
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Dialkyl hydrogen, sodium dialkyl, and dialkyl silyl phosphites react with trichloroacetonitrile by the Atherton-Todd scheme.Trialkyl phosphites add at the C(*)N bond of trichloroacetonitrile with the formation of trialkyl phosphorimidates.
- Kutyrev, A. A.,Moskva, V. V.,Alparova, M. V.
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p. 1332 - 1336
(2007/10/02)
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- Reactions of Group V Metal Compounds with Sulfur Trioxide
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Trialkylphosphines react with equimolar amounts of sulfuric trioxide to form the 1:1 adducts R3P(1+)-SO3(1-).Trialkylarsines and -stibines undergo sulfur trioxide insertion reaction across the metal-carbon bond to give the trisulfonates of the metal M(OSO2R)3 (M=As,Sb).The reactions of trialkyl phosphites, with sulfur trioxide yield trialkyl phosphonates, trialkyl thiophosates, dialkyl alkylphosphonates, dialkyl sulfates, and polymers which contain phosphorus atoms.The reactions of trialkoxyarsines and -stibines result in the insertion of sulfur trioxide across the metal-oxygen bond to form the alkoxymetal alkylsulfates (RO)3-nM(OSO3R)n (M=As,Sb; n=1,2,3) depending on the stoichiometric ratios of the reagents used.Pyrolysis of the metal sulfates gives dialkyl sulfates and undistillable residues containing the metals.
- Ando, Fumio,Koketsu, Jugo,Ishii, Yoshio
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p. 3495 - 3499
(2007/10/02)
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