- Carboranyl Oligonucleotides. 1. Synthesis of Thymidine(3',5')thymidine (o-Carboran-1-ylmethyl)phosphonate
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Using methyl (o-carboran-1-ylmethyl)phosphonate 6 as a novel and versatile borophosphonylating agent, 5'-O-(monomethoxytrityl)thymidine 3'-O- (8) and thymidine(3',5')thymidine (o-carboran-1-ylmethyl)phosphonate (12) were synthesized.The internucleotide (o-carboran-1-ylmethyl)phosphonate linkage was resistant to cleavage by phosphorodiesterases.The dinucleotide 12 represents a new class of modified lipophilic oligonucleotide-bearing carboranyl residue, designed as a carrier for boron neutron capture therapy and for potential use in antisense oligonucleotide technology.
- Lesnikowski, Zbigniew J.,Schinazi, Raymond F.
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- Molecular interactions of monosulfonate tetraphenylporphyrin (TPPS1) and meso-tetra(4-sulfonatophenyl)porphyrin (TPPS) with dimethyl methylphosphonate (DMMP)
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The molecular interactions of monosulfonate tetraphenylporphyrin (TPPS1) and meso-tetra(4-sulfonatophenyl)porphyrin (TPPS) with dimethyl methylphosphonate (DMMP) have been investigated by UV-vis and fluorescence spectroscopies. The association
- Huo, Danqun,Yang, Limin,Hou, Changjun,Fa, Huanbao,Luo, Xiaogang,Lu, Yi,Zheng, Xiaolin,Yang, Jun,Yang, Li
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- Trimethyl Phosphite Adsorbed on Silica: An NMR and Infrared Study
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Infrared spectroscopy and phosphorus-31 magic angle spinning nuclear magnetic resonance spectroscopy have been used to study the adsorption of trimethyl phosphite (TMP) on silica.At 23 deg C TMP reacts rapidly with surface silanol groups to give SiOCH3 as a chemisorbed product and liquid dimethyl phosphite (DMP).However, formation of DMP ceases when about half of the SiOH groups have been consumed because DMP strongly hydrogen bonds to the remaining silanols thereby inhibiting further reaction between TMP and SiOH.TMP also undergoes isomerization to dimethyl methylphosphonate (DMMP) which is catalyzed by SiOH.As the number of initial silanol groups is decreased (by using higher temperatures of vacuum activation) the quantity of DMP produced decreases whereas that of DMMP increases.A mechanism for formation of DMP and DMMP has been suggested.At 100 deg C isomerization does not occur, all SiOH groups are consumed, and the major product is DMP/SiOCH3 accompanied by a small quantity of a chemisorbed phosphorus-containing species having the proposed structure (SiO)2P-H(=O).The latter is stable up to 400 deg C.If TMP is heated with silica from 100 to 400 deg C, in addition to SiOCH3, the major new chemisorbed product of the reaction which can be identified by IR and NMR is (SiO)2P-Me(=O) (Me = CH3).The advantages of a combined IR-NMR approach are discussed.
- Gay, Ian D.,McFarlan, A. J.,Morrow, B. A.
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- Intensified Continuous Flow Michaelis-Arbuzov Rearrangement toward Alkyl Phosphonates
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Herein is described the development of an intensified continuous flow process for the preparation of a library of alkyl phosphonates through a Michaelis-Arbuzov rearrangement. A careful process optimization and thorough analysis of the competitive reactions led to a very attractive protocol with unprecedented productivities (up to 4.97 kg of material per day) and a low environmental footprint with the absence of solvent, additives, catalysts, and waste. In-line low-field 31P NMR monitoring was conveniently implemented for rapid optimization and process monitoring. Two key alkyl phosphonate intermediates were also assessed for the unprecedented diazene dicarboxylate-mediated electrophilic amination under continuous flow conditions toward the α-aminophosphonic acid derivatives of Pphenylalanine and Palanine, bioisosters of the natural amino acids phenylalanine and alanine, respectively.
- Monbaliu, Jean-Christophe M.,Toupy, Thomas
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supporting information
p. 467 - 478
(2022/02/25)
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- Challenging synthesis of bisphosphonate derivatives with reduced steric hindrance
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An alternative approach is reported for the synthesis of methyl ester protected bisphosphonate building blocks, such as methylene bisphosphonate, vinylidenebisphosphonate and aryl substituted prochiral vinylidenebisphosphonates, that cannot be obtained directly from dimethyl phosphite and dichloromethane.
- Chiminazzo, Andrea,Sperni, Laura,Fabris, Fabrizio,Scarso, Alessandro
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- Experimental and computational studies on the formation and biological properties of the simplest polyfluoroalkyl phosphonates
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A representative set of the simplest dialkyl polyfluoroalkylphosphonates was in silico profiled against their absorption, distribution, metabolism, and excretion with the use of the SwissADME tool. Promising results of the screening led us to attempt to synthesize the title compounds for further biological investigations. Detailed experimental and quantum-theoretical (DFT) investigations were performed to reveal that the studied compounds could not be obtained through the standard Michaelis-Arbuzov or Michaelis-Becker reactions. Kinetic studies showed that trimethyl phosphite undergoes a reaction with 1,1,1-trifluoro-2-iodoethane several orders of magnitude slower than a side reaction. The difficulty was overcome by developing a simple three-step synthesis path that involves only readily available substrates. The newly synthesized substances were tested against several cell lines. The in vitro research revealed that both dimethyl and diethyl (2,2,3,3,3-pentafluoropropyl)phosphonate exhibited toxicity towards glioblastoma cells (U-87 MG) at a considerably lower concentration than known chemotherapeutics. This journal is
- Tokarz, Paulina,Gostyński, Bart?omiej,Tokarz, Pawe?,Zagórski, Piotr M.
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p. 10933 - 10945
(2020/07/15)
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- Preparation method of cyclic phosphonate flame retardant
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The invention discloses a preparation method of a cyclic phosphonate flame retardant, which relates to the technical field of organic phosphorus flame retardant synthesis. The method comprises the following steps of taking trimethylolpropane and trimethyl phosphite as raw materials with the feed mole ratio of 1: 2-4, selecting methyl benzenesulfonate or methyl p-toluenesulfonate as a catalyst, controlling proper process parameters such as catalyst quantity, temperature, time and the like, and carrying out transesterification and rearrangement reaction to obtain the phosphonate flame retardantwith a cyclic structure and the byproduct dimethyl methylphosphonate flame retardant. The method provided by the invention has the advantages of few raw material varieties, easy source, low cost, rapid reaction, high efficiency, environment-friendly process, energy conservation and consumption reduction; the product prepared by the method is the same as the product prepared by the existing method,but the production period is shortened by 2/3-3/4, the production capacity is greatly improved, and the method is suitable for industrial production.
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Paragraph 0030-0038
(2020/07/24)
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- METHOD FOR PRODUCING ORGANOPHOSPHORUS COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for producing an organophosphorus compound which has excellent energy efficiency without containing a halogenated alkyl or a by-product derived from a halogenated alkyl. SOLUTION: There is provided a method for producing an organophosphorus compound by reacting a trivalent organophosphorus compound represented by the following general formula (1) in the presence of a super strong acid and/or at least one acid catalyst containing a solid superstrong acid catalyst to generate a pentavalent organophosphorus compound represented by the following general formula. (where Z1 represents OR2 or R2; Z2 represents OR3 or R3; R1, R2 and R3 represent an alkyl group, an alkenyl group or the like; when R2 and R3 are an alkyl group or the like, R2 and R3 may be bonded to each other to form a cyclic structure; and R1 may be a hydrogen atom.) SELECTED DRAWING: None COPYRIGHT: (C)2020,JPOandINPIT
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Paragraph 0045; 0079
(2020/05/02)
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- Solvent-Free Michaelis-Arbuzov Rearrangement under Flow Conditions
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The first solvent- and catalyst-free procedure for the Michaelis-Arbuzov reaction under flow conditions was developed. A variety of alkylphosphonic esters could be obtained using this protocol starting from the corresponding trialkyl phosphites and even catalytic amounts of alkyl halides with very short reaction times (8.33-50 min) and excellent conversions. In general, this protocol works effectively when the alkyl halide is used in catalytic amounts as low as 5-10% only if it concerns the synthesis of homo alkylphosphonates. One equivalent and an excess of alkyl halides should be used in the reaction with alkyl phosphite if the alkyl group of the selected substrates differ. Thus, it provides a sustainable, fast alternative to the existing methods for the preparation of alkylphosphonates. The isolation of the reaction products is straightforward due to the lack of solvents and a high purity of the obtained products (conv ≥ 99%), and notably, in the catalytic procedures there are only traces of alkyl halides formed after the reaction is complete. The reactions conducted using a glass microreactor chip with an internal volume of 250 μL allow the production of 1.6-1.95 g of organophosphorus esters per hour.
- Jasiak, Aleksandra,Mielniczak, Grazyna,Owsianik, Krzysztof,Koprowski, Marek,Krasowska, Dorota,Drabowicz, Józef
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p. 2619 - 2625
(2019/02/26)
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- Water determines the products: An unexpected Br?nsted acid-catalyzed PO-R cleavage of P(iii) esters selectively producing P(O)-H and P(O)-R compounds
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Water is found able to determine the selectivity of Br?nsted acid-catalyzed C-O cleavage reactions of trialkyl phosphites: with water, the reaction quickly takes place at room temperature to afford quantitative yields of H-phosphonates; without water, the reaction selectively affords alkylphosphonates in high yields, providing a novel halide-free alternative to the famous Michaelis-Arbuzov reaction. This method is general as it can be readily extended to phosphonites and phosphinites and a large scale reaction with much lower loading of the catalyst, enabling a simple, efficient, and practical preparation of the corresponding organophosphorus compounds. Experimental findings in control reactions and substrate extension as well as preliminary theoretical calculation of the possible transition states all suggest that the monomolecular mechanism is preferred.
- Li, Chunya,Wang, Qi,Zhang, Jian-Qiu,Ye, Jingjing,Xie, Ju,Xu, Qing,Han, Li-Biao
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supporting information
p. 2916 - 2922
(2019/06/18)
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- A reaction in the preparation of glyphosate, the application of the phosphine type flame retardant (by machine translation)
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The invention relates to an application of a new intramolecular heterogeneous reaction of phosphor in the preparation of products of glyphosate, phosphine fire retardants and chloromethyl phosphonic dichloride. The application which develops a new approach of a synthetic route of the products and improves disadvantages of high original synthetic technology cost and large wastewater discharge amounts of the products can reach industrial design standards of clear production.
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Paragraph 0062-0064
(2018/12/13)
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- Synthesis method of glufosinate ammonium intermediate alkyl phosphodiester compound
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The invention discloses a synthesis method of a glufosinate ammonium intermediate alkyl phosphodiester compound. According to the method, phosphite trimester and halogenated hydrocarbon or alcohol or phenol are subjected to substitution reaction so as to obtain the glufosinate ammonium intermediate alkyl phosphodiester. The method takes phosphite trimester as the raw material to carry out substitution reaction with halogenated hydrocarbon or alcohol or phenol at certain temperature to obtain the corresponding product alkyl phosphodiester, and the product can be further prepared into glufosinate ammonium. The method changes the existing process of using methyl diethyl phosphite to prepare glufosinate ammonium, has the characteristics of low production cost, safety and environmental protection, and at the same time avoids the risk in the process of industrialization.
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Paragraph 0029; 0030
(2017/04/18)
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- The optically pure sodium alcoholate dextrorotary chlorine forefront of the method for the preparation of
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The invention relates to a preparation method of optically pure dextro cloprostenol sodium. The method comprises the following steps: using the combination of ketonic acid and S-phenylethylamine resolving agent, and carrying out chiral resolution to obtain S-propenylphosphonate with the structural formula of R-ketonic acid; then separating to obtain R-chlorone and preparing to obtain R-cloprostenol sodium. The preparation method has the benefits that the optically pure dextro cloprostenol sodium in the invention is called D-cloprostenol sodium for short, the using amount only needs one third of cloprostenol sodium being a racemic modification in current market, and the pesticide effect is obviously better than cloprostenol sodium with three times of using amount.
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Paragraph 0135; 0136
(2018/02/04)
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- Direct conversion of phosphonates to phosphine oxides: An improved synthetic route to phosphines including the first synthesis of methyl JohnPhos
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The synthesis of tertiary phosphine oxides from phosphonates was achieved reliably and in good to excellent yields using stoichiometric amounts of alkyl or aryl Grignard reagents and sodium trifluoromethanesulfonate (NaOTf). In the absence of the NaOTf additive, covalent coordination oligomers of magnesium and phosphorus species dominate the reaction, producing very low yields of phosphine oxide, but high conversions of the phosphonate starting material. Mechanistic studies revealed that a five-coordinate phosphorus species - not a phosphinate - is the reaction intermediate. A diverse array of phosphonates was converted to phosphine oxides using a variety of Grignard reagents for direct carbon-phosphorus functionalization. This new methodology especially simplifies the synthesis of dimethylphosphino (RPMe2)-type phosphines by using air-, water-, and silica-stable intermediates. To highlight this reaction, a new Buchwald-type ligand ([1,1′-biphenyl]-2-yldimethylphosphine, or methyl JohnPhos) and a classic bidentate phosphine, bis(diphenylphosphino)propane (dppp), were synthesized in excellent yields.
- Kendall, Alexander J.,Salazar, Chase A.,Martino, Patrick F.,Tyler, David R.
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supporting information
p. 6171 - 6178
(2015/02/19)
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- Polymer-supported sulfonated magnetic resin: An efficient reagent for esterification of O-alkyl alkylphosphonic-and carboxylic-acids
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A mild and efficient synthetic method has been developed for the esterification of O-alkyl alkylphosphonic-and carboxylic-acids using polymer-supported sulfonated magnetic resins. Polymer-supported resins are recovered using an external magnet and reused several times.
- Purohit, Ajay Kumar,Kumar, Ajeet,Singh, Varoon,Goud D, Raghavender,Jain, Rajiv,Dubey
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supporting information
p. 6844 - 6846
(2015/01/09)
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- Kinetic assessment of N-methyl-2-methoxypyridinium species as phosphonate anion methylating agents
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Organophosphate nerve agents and pesticides are potent inhibitors of acetylcholinesterase (AChE). Although oxime nucleophiles can reactivate the AChE-phosphyl adduct, the adduct undergoes a reaction called aging. No compounds have been described that reactivate the aged-AChE adduct. A family of 2-methoxypyridinium species which reverse aging in a model system is presented. A kinetic study of this system, which includes an SAR analysis, demonstrates that the reaction is highly tunable based on the ring substituents.
- Topczewski, Joseph J.,Quinn, Daniel M.
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supporting information
p. 1084 - 1087
(2013/04/10)
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- Mild and efficient esterification of alkylphosphonic acids using polymer-bound triphenylphosphine
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Mild and efficient esterification of alkylphosphonic acids using primary alcohols, iodine, imidazole and polymer-bound triphenylphosphine is developed.
- Purohit, Ajay Kumar,Pardasani, Deepak,Tak, Vijay,Kumar, Ajeet,Jain, Rajeev,Dubey, Devendra Kumar
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experimental part
p. 3795 - 3797
(2012/09/21)
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- Interaction of α,α-difluoroazides with trivalent phosphorus compounds and triphenylantimony
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α,α-Difluoroazides react with triphenylantimony and various compounds of trivalent phosphorus according to the oxidative fluorination scheme. In the case of trivalent phosphorus compound the primary products are phosphazenes, phosphazides or difluorophosphoranes that may undergo further transformations to the corresponding fluorine derivatives of pentavalent phosphorus. Pleiades Publishing, Ltd., 2010.
- Lermontov,Polivanova,Shkavrov
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experimental part
p. 1646 - 1651
(2011/02/18)
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- The Michaelis-Becker reaction in phosphonium and imidazolium ionic liquids
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The Michaelis-Becker reaction was performed in imidazolium ionic liquids using sodium hydroxide as base or sodium dialkylphosphites with good yield and selectivities. The analogous reaction performed in phosphonium ionic liquids resulted in decomposition to phosphine oxides. Copyright
- Vu, Anh P.,Shaffer, Erika A.,Byington Congiardo, Laura K.,Knight, D. Andrew
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experimental part
p. 1845 - 1849
(2010/11/02)
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- Synthesis of a phosphonate-linked aminoglycoside-coenzyme a bisubstrate and use in mechanistic studies of an enzyme involved in aminoglycoside resistance
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Aminoglycoside N-6′-acetyltransferases (AAC(6′)s) are important determinants of antibiotic resistance. A good mechanistic understanding of these enzymes is essential to overcome aminoglycoside resistance. We have previously reported the synthesis of amide- and sulfonamide-linked aminoglycoside-coenzyme A conjugates, which were useful mechanistic and structural probes of AAC(6′)s. We report here the synthesis of a phosphonate-linked aminoglycoside-coenzyme A variant, which is expected to be a superior mimic of the tetrahedral intermediate proposed for catalysis by AAC(6′)s. This synthetic target is especially challenging for a number of reasons, including the presence of multiple functional groups, the water solubility of both starting materials, and incompatibility of PIII chemistry with water. We have overcome these challenges by adding the expensive coenzyme A in the last step by means of an elegant Michael-type addition onto a vinylphosphonate in water. Overall, a single protection step was needed. The decreased inhibitory potency of this bisubstrate compared to that of the amide-linked analogue suggests that Enterococcus faecium AAC(6′)-Ii may not stabilize the proposed tetrahedral intermediate, and may act mainly through proximity catalysis.
- Gao, Feng,Yan, Xuxu,Auclair, Karine
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experimental part
p. 2064 - 2070
(2009/11/30)
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- PROCESS FOR MAKING DIHYDROCARBYL HYDROCARBONPHOSPHONATES
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This invention provides a process for the preparation of a dihydrocarbyl hydrocarbonphosphonate. The process comprises forming a reaction mixture from components comprising (i) at least one dihydrocarbyl phosphite, (ii) at least one alkali metal hydrocarbyloxide, and (iii) at least one alcohol, so that a dihydrocarbyl hydrocarbonphosphonate is formed.
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Page/Page column 8
(2009/01/24)
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- P-Toluenesulfonic acid-Celite as a reagent for synthesis of esters of alkylphosphonic acids under solvent-free conditions
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The coupling reaction of alkylphosphonic acids and alcohols on the surface of p-toluenesulfonic acid-Celite under mild and solvent-free conditions gave the corresponding phosphonates in excellent yields. This method provides a useful rapid synthesis of phosphonates for use in the unambiguous identification of chemical warfare agents.
- Gupta, Arvind K.,Kumar, Rajesh,Dubey, Devendra K.,Kaushik
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p. 328 - 331
(2008/02/10)
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- Borrowing hydrogen: Iridium-catalysed reactions for the formation of C-C bonds from alcohols
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Alcohols have been employed as substrates for C-C bond-forming reactions which involve initial activation by the temporary removal of hydrogen to form an aldehyde. The intermediate aldehyde is converted into an alkene via a Horner-Wadsworth-Emmons reaction, nitroaldol and aldol reactions. The 'borrowed hydrogen' is then returned to the alkene to form a C-C bond. The Royal Society of Chemistry 2006.
- Black, Phillip. J.,Cami-Kobeci, Gerta,Edwards, Michael G.,Slatford, Paul A.,Whittlesey, Michael K.,Williams, Jonathan M. J.
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p. 116 - 125
(2007/10/03)
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- A chelating β-diketonate/phenoxide ligand and its coordination behavior toward titanium and scandium
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Dibenzoylmethane derivatives with one (L1H2) or both (L2H3, L3H3) benzenes linked at their ortho positions to 4,6-di-tert-butylphenol moieties by two-carbon linkers have been synthesized. The mono-β-diketone-monophenol ligand L 1H2 is metalated by titanium alkoxides to form the homoleptic complex (L1)2Ti and heteroleptic complexes (L1)Ti([OCH2CH2]2NR) (R = H, CH 3), and reacts with Cp3Sc to form CpSc(L1). These are the first examples of complexes of a β-diketonate ligand which is further chelating to a single metal center. Crystallographic analysis of (L1)2Ti indicates that the 10-membered ring allows chelation of the phenoxide with little strain, and both fac and mer geometries are accessible in solution. Protonolysis of the second cyclopentadienyl ring of Cp3Sc appears to take place by an indirect, Cp3Sc- catalyzed pathway. The Royal Society of Chemistry 2006.
- Schroeder, Tobias,Ugrinova, Vesela,Noll, Bruce C.,Brown, Seth N.
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p. 1030 - 1040
(2007/10/03)
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- Phase-transfer-catalyzed Michaelis-Becker synthesis of dialkyl methyl phosphonates
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A liquid-liquid phase-transfer-catalyzed (PTC) Michaelis-Becker reaction was adopted in the preparation of dialkyl methyl phosphonate (R=Me, iPr; nBu, and iBu). This was performed by the reaction of an appropriate dialkyl hydrogen phosphonate with methyl iodide in the presence of benzyl triethyl ammonium chloride and sodium hydroxide as PTC and base, respectively. A liquid-liquid two-phase system (H2O/CH2Cl2) introduced a suitable situation for the preparation of dialkyl methyl phosphonates with bulky alkyl groups (R=iPr, nBu, and iBu), but with R=Me, the hydrolysis of dimethyl hydrogen phosphonate (reagent) reduced the yield to 22%. In this case, a solid-liquid PTC-free system was successfully applied and yield of over 80% was obtained. Copyright Taylor & Francis Group, LLC.
- Fakhraian, Hossein,Mirzaei, Akbar
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p. 511 - 518
(2007/10/03)
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- An efficient method for the esterification of phosphonic and phosphoric acids using silica chloride
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Silica chloride is used as an effective heterogeneous catalyst for the rapid esterification of alkyl/aryl phosphonic/phosphoric acids to their corresponding alkyl/aryl phosphonates/phosphates under mild conditions with quantitative yields.
- Sathe, Manisha,Gupta, Arvind K.,Kaushik
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p. 3107 - 3109
(2007/10/03)
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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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- Surface-mediated solid phase reactions: A simple, efficient and base-free synthesis of phosphonates and phosphates on Al2O3
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Al2O3-supported solvent free condensation of alkylphosphonic dichlorides with alcohols at room temperature yielded phosphorus esters in excellent yields.
- Acharya, Jyotiranjan,Shakya, Purushottam D.,Pardasani, Deepak,Palit, Meehir,Dubey, Devendra K.,Gupta, Arvind K.
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p. 194 - 196
(2007/10/03)
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- Reactions of trialkyl phosphites with mono- and diacylals of halo-substituted acetic acids
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Trialkyl phosphites react with diacylals of di- and trichloroacetic acids by the pathway of the Perkow reaction; with monoacylals of bromo- and iodoacetic acids, by the pathway of the classical Arbuzov reaction; and with monoacylals of di- and trichloroacetic acids, by the pathway of the nonclassical Arbuzov reaction.
- Gazizov,Gaisin,Khairullin,Safina,Karimova,Petrova
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p. 1738 - 1741
(2007/10/03)
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- Reaction of 2,4-Difunctional Esters of 5-tert-Butylfuran-3-carboxylic Acid with Nucleophilic Reagents
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Ethyl 5-tert-butyl-4-(chloromethyl)-2-methylfuran-3-carboxylate was brominated with N-bromosuccinimide to obtain the corresponding 2-bromomethyl derivative. The latter is selectively phosphorylated with trimethyl and triethyl phosphites by the bromomethyl group. The resulting [4-(chloromethyl) furyl]methylphosphonates in the presence of secondary amines and sodium butanethiolate behave as alkylating agents, while sodium phenolate causes their decomposition. 4-Acetoxymethyl- and 4-phenoxymethyl derivatives of the starting product are also selectively brominated with N-bromosuccinimide by the 2-methyl group. The first of the 2-(bromomethyl)furans formed is smoothly phosphorylated with trimethyl phosphite, while the second one under the action of triethyl phosphite gives a mixture of phosphorylation and debromination products. In all the cases, an additional electron-acceptor group in position 4 of alkyl 2-(bromomethyl)-5-tert-butylfuran-3-carboxylate considerably accelerates the Arbuzov reaction.
- Pevzner
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p. 413 - 417
(2007/10/03)
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- An efficient separation method for enol phosphate and corresponding β-ketophosphonate from their mixtures under aqueous conditions
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Separation of a mixture β-ketophosphonate 3 and their corresponding enol phosphate 4 is efficiently carried out in aqueous alkaline solutions. Enol phosphate 4 is first extracted with hexanes:dichloromethane (19:1). Acidification of the aqueous layer followed by extraction of the β-ketophosphonate 3 with dichloromethane completes the separation. Thus, when 1-bromo-2,4-pentadione la reacted with triethyl phosphite to give diethyl (2,4-dioxopentyl)phosphonate 3a (Arbuzov-product) and the corresponding enol phosphate 4a (Perkow-product), separation of the two compounds was carried out using this method.
- Moorhoff, Cornelis M.
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p. 2069 - 2086
(2007/10/03)
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- Lewis acid catalyzed room-temperature Michaelis-Arbuzov rearrangement
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The taming of the shrew! For the first time, a broadly applicable efficient room-temperature Arbuzov rearrangement is described. This reaction is accomplished through an atom-economical Lewis acid catalyzed process (see scheme, TMSOTf=trimethylsilyl trifluoromethane-sulfonate). The method has been generalized to primary and activated secondary phosphites, phosphinites, and phosphonites.
- Renard, Pierre-Yves,Vayron, Philippe,Leclerc, Eric,Valleix, Alain,Mioskowski, Charles
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p. 2389 - 2392
(2007/10/03)
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- Trimethylsilyl halide-promoted Michaelis-Arbuzov rearrangement
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(Matrix presented) We describe a new, straightforward, and easy-to-handle method for achieving an unprecedented trimethylsilyl halide-catalyzed Michaelis-Arbuzov-like rearrangement. This rearrangement occurs at temperatures from room temperature to 80°C and does not require addition of any alkyl halide. The scope and limitations of this new reaction are explored, as well as its mechanism.
- Renard, Pierre-Yves,Vayron, Philippe,Mioskowski, Charles
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p. 1661 - 1664
(2007/10/03)
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- Microwave catalyzed reactions of H-dimethylphosphonate with oxiranes
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Microwave catalyzed reactions of H-dimethylphosphonate with 1,2-epoxydecane, 5,6-epoxy-1-hexene, 1,2-epoxybutane and cyclohexene oxide have been found to cause oxirane ring opening, deoxygenation and hydrophosphorylation. 1,2-Epoxydecane gave three pairs
- Munavalli,Rohrbaugh,Berg,Longo,Durst
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p. 215 - 230
(2007/10/03)
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- Intramolecular catalysis of aminolysis of phosphorus heterocycles incorporating an α-aminoamide moiety. III. Synthesis of 2-oxo or 2-thioxo 1,3-disulfonyl-1,3,2-diazaphospholidines and reactions with amines and alcohols
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A series of 2-oxo or 2-thioxo 1,3-disulfonyl-1,3,2-diazaphospholidines 4 was prepared by condensation of phosphonyl dichlorides 2 with bis-N,N′-sulfonylethylenediamines 1 in pyridine. Complete aminolysis or alcoholysis of heterocycles 4 took place with regeneration of sulfonyldiamines 1. These reactions are very sensitive to steric hindrance, and hydrolysis is generally favoured over aminolysis. The results are discussed in terms of mechanisms of phosphorylation.
- Dujols,Mulliez
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p. 475 - 480
(2007/10/03)
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- Organophosphorus chemistry. Part 1: The synthesis of alkyl methylphosphonic acids
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Several alkyl hydrogen methylphosphonates of structure RO(HO)P(O)Me were synthesised by a three-stage route [R =i-Pr, n-Bu, i-Bu, s-Bu, pinacolyl Me3C-CH(Me)-, cyclopentyl and cyclohexyl]. Trimethyl phosphite was transesterified with alcohols in the presence of sodium catalyst to give the mixed phosphites (MeO)2POR in 6-64% yield. Treatment of these with methyl iodide gave alkyl methyl methylphosphonates RO(MeO)P(O)Me in 66-95% yield. Selective demethylation of these compounds by bromotrimethylsilane, followed by methanolysis of the phosphorus silyl esters RO(Me3SiO)P(O)Me, gave the hydrogen phosphonates in 60-97% yield.
- Timperley, Christopher M.,Bird, Michael,Holden, Ian,Black, Robin M.
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- Microwave irradiation in organophosphorus chemistry 1: The Michaelis-Arbuzov reaction
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A diverse series of phosphonate esters have been prepared using a domestic microwave oven. The microwave enhanced Michaelis-Arbuzov reaction shows remarkable rate acceleration under microwave irradiation and allows the facile synthesis, and in certain cases easy workup, of alkyl, α-substituted and aryl phosphonates.
- Kiddle, James J.,Gurley, Alison F.
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p. 195 - 205
(2007/10/03)
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- Alkali metal alkoxide clusters: Convenient catalysts for the synthesis of methylphosphonates
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Alkali metal alkoxides are good catalysts (1-8 mol %) for promoting the interchange reaction between carbonyl and phosphorus esters. This reactivity leads to convenient methodologies for the synthesis of symmetric and unsymmetric alkyl-substituted methylphosphonates from dimethyl methylphosphonate (DMMP). Reactions rates are high with initial turnover frequencies (N(t)) in excess of 1 x 106 h-1 observed and with KO(t)Bu > NaO(t)Bu > LiO(t)Bu. The reactions were sensitive to steric effects in the product methylphosphonates with reaction rates paralleling the size of the transferring alkoxide (n-alkyl > isoalkyl >> tert-alkyl). For the test reaction DMMP + isopropyl acetate, substitution kinetics were consistent with a scenario wherein each methoxide is replaced sequentially, and the substitution rate for the second displacement is substantially slower than the first. Kinetic studies on the first substitution process were indicative of a concentration dependent rate law; a scenario most easily accounted for by a coupled transesterification wherein alkoxide reversibly and independently adds to phosphonate and ester.
- Kissling, Rebecca M.,Gagne, Michel R.
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p. 1585 - 1590
(2007/10/03)
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- Specific Features of Bromination of Substituted α-Methylfurans with N-Bromosuccinimide and of Reaction of the Resulting Products with Trimethyl Phosphite
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Bromination of ethyl 2- and 5-methylfuran-3-carboxylates with N-bromosuccinimide proceeds exclusively at the methyl group and yields mono- and dibromides depending on the reagent ratio. The corresponding diethylamides are brominated first at the free α-position of the ring and then at the methyl group. Under the action of trimethyl phosphite on the dibromo amide the side-chain bromine atom is replaced by the dimethoxyphosphoryl group, whereas 2-dibromomethyl-3-furancarboxylate catalyzes transformation of trimethyl phosphite to dimethyl methylphosphonate, and its 5-isomer takes part in various redox reactions to form 5-formyl and 5-dimethoxyphosphorylmethyl derivatives of 3-furancarboxylic acid.
- Pevzner,Ignat'ev,Ionin
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p. 542 - 547
(2007/10/03)
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- Palladium-Catalyzed Phase-Transfer Arylation of Dialkyl Phosphonates
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Palladium-catalyzed phase-transfer arylation of dialkyl phosphonates with various iodo- and bromoarenes has been studied. The arylation has also been effected in the absence of ligand. A simple preparative procedure for synthesizing arylphosphonic acids has been developed.
- Kabachnik,Solntseva,Izmer,Novikova,Beletskaya
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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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The use of ultrasonic activation in Michaelis-Arbuzov reaction promote a by-product in the case of silyl derivatives and in the synthesis of methylene diphosphonate. A mechanism is proposed in which the phosphite give a nucleophilic attack on the quasiphosphonium ion in place of the halide species.
- Winum, Jean-Yves,Kamal, Mehrnaz,Agnaniet, Huguette,Leydet, Alain,Montero, Jean-Louis
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- Polysubstituted 2-(bromomethyl)furans in the arbuzov reaction
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α-Bromomethyl derivatives of ketoesters, dinitriles, and diesters of the furan series react with trimethyl phosphite under conditions of the Arbusov reaction with formation of the corresponding phosphonates. The same is true of phosphorylation of 2-(bromomethyl)-5-phenylfuran and its derivatives, containing alkoxycarbonyl, keto or cyano group in the β-position of the ring. Phosphorylation of 5-bromo-substituted 2-(bromomethyl)-3-(ethoxycarbonyl)-4-methylfuran phosphorylates by trimethyl phosphite occurs exclusively by the way substitution of the bromine atom of the bromomethyl group, bypassing the furan ring bromine. Comparison of the behavior of polysubstituted halofuran derivatives under conditions of the Arbuzov and Michaelis-Becker reactions is carried out. It is established that increasing conjugation chain of the molecule favors the Arbuzov phosphorylation, but induces a redox reaction with sodium diethyl phosphite.
- Pevzner,Ignat'ev,Ionin
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p. 743 - 749
(2007/10/03)
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- Photolyses of Derivatives of Naphthyl and Anthryl Phosphates and Methylphosphonates
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Upon UV irradiation in acetonitrile, tri-1-naphthyl phosphate and di-1-naphthyl methylphosphonate underwent intramolecular rearrangement and ipso-coupling to give 1,2'-binaphthalen-1'-ol and 1,1'-binaphthalene, respectively.In the photolyses of tris(4-methoxy-1-naphthyl) phosphate and bis(4-methoxy-1-naphthyl) methylphosphonate in methanol, 4,4'-dimethoxy-1,1'-binaphthalene, 1',4,4'-trimethoxy-1,2'-binaphthalene, and 2,4,4'-trimethoxy-1,1'-binaphthalene were generated.Tri-9-anthryl phosphate and di-9-anthryl methylphosphonate underwent intramolecular (4+4) photocycloaddition between two anthryl groups.The fluorescence spectra of the naphthyl derivatives had two emission bands ascribed to an intramolecular excimer and a monomer, but the fluorescence spectra of the anthryl derivatives had only a monomer emission band.These photoluminescence behaviors are closely related to the reactivities of the compounds.
- Nakamura, Mitsunobu,Sawasaki, Koichi,Okamoto, Yoshiki,Takamuku, Setsuo
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p. 3189 - 3198
(2007/10/03)
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- Hydroxymethylphosphonate: Novel oligonucleotide analogue
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Thymidine(3',5')thymidine hydroxymethylphosphonate (10), the first oligonucleotide bearing hydroxymethylphosphonate function, and t-butylammonium 5'-O-monomethoxytritylthymidine 3'-O-acetoxymethylphosphonate (7), oligonucleotide monomer, were synthesized using t-butylammonium O-methylacetoxymethylphosphonate (4) as a novel phosphonylating agent. Hydroxymethylphosphonate internucleotide linkage is stable at physiological pH and resistant to 3'- and 5'-exonucleases. While retaining the neutral character of the phosphonate modification, the presence of hydroxymethyl function increases hydrophilicity of hydroxymethylphosphonateoligonucleotide and its solubility in water compared to the parent methylphosphonate analogue. Therefore, hydroxymethylphosphonate modification can be used to fine-tune the physicochemical properties of antisense oligonucleotides.
- Lesnikowski
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p. 128 - 139
(2007/10/02)
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- Photolysis of 4-Methoxyphenyl Aryl Alkylphosphonates
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UV irradiation of bis(4-methoxyphenyl) methylphosphonate 1a in methanol gave 4,4'-dimethoxybiphenyl 2a as the main product through an intramolecular excimer.With 4-cyanophenyl-4-methoxyphenyl methylphosphonate 1b 4-cyano-4'-methoxybiphenyl 2c and 4-cyano-2-(4'-methoxyphenyl)phenyl methylphosphonate 4b were obtained through an intramolecular exciplex. 3-Cyanophenyl-4-methoxyphenyl methyl phosphonate 1c gave only 3-cyano-4'-methoxybiphenyl 2f.Methyl 4-methoxyphenyl 4-chlorobenzylphosphonate 5a gave dimethyl 4-chlorobenzyl 2-(4'-methoxyphenyl)phosphonate and dimethyl 2-(4'-methoxyphenyl)benzylphosphonate.
- Nakamura, Mitsunobu,Sawasaki, Kouiti,Okamoto, Yoshiki,Takamuku, Setsuo
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p. 141 - 146
(2007/10/02)
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- Preparation of dialkyl allylphosphonic acid diesters
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An improved process for the production of allylphosphonic acid dialkyl esters in high yield and selectivity by the gradual addition of trialkyl phosphite to react with the appropriate allyl halide in the presence of a divalent nickel catalyst and, optionally, a polymerization inhibiting compound, e.g. hydroquinone.
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- Phosphoranyl Radicals as Reducing Agents: SRN1 Chains with Onium Salts and Neutral Nucleophiles
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Redox radical chain reactions of trivalent organophosphorus compounds (PZ3) with diaryliodonium (Ar2I+) and triarylsulfonium (Ar3S+) salts to give arylphosphonium (ArP+Z3) salts and iodoarenes (ArI) or diaryl sulfides (Ar2S) are reported.The key propagation step in these SRN1 reactions is a single-electron reduction of the onium salts by intermediate phosphoranyl radicals (ArP.Z3).The observation of competitions between solvent molecules and phosphine establishes the intermediacy of free aryl radicals and allows estimates of rate constants for addition of p-tolyl radicals to triphenylphosphine (k ca. 3 * 1E8 M-1 s-1) and to trimethyl phosphite (k ca. 2 * 1E8 M-1 s-1).The intermediate phosphoranyl radicals can also partition between competitive reaction pathways; the aryltributylphosphoranyl radical, ArP.Bu3, for example, partitions between unimolecular α-cleavage of butyl radical and chain-propagating electron transfer to diaryliodonium salt.The relative amounts of these two pathways allows an estimate of the rate constant for electron transfer, kSET ca. 4 * 1E9 M-1 s-1.
- Kampmeier, J. A.,Nalli, Thomas W.
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p. 943 - 949
(2007/10/02)
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- ELECTROCHEMICALLY INDUCED PROCESSES IN THE FORMATION OF PHOSPHORUS ACID DERIVATIVES. 1. SYNTHESIS OF TRIALKYL PHOSPHATES FROM WHITE PHOSPHORUS
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An electrochemical method, based on the joint action of nucleophilic and electrophilic reagents on P4, is proposed in order to utilize white phosphorus in the formation of the esters of phosphorus acids.The action of alkoxide ions on white phosphorus in an alcohol medium in the presence of iodine generated at the anode leads to the formation of phosphate esters.A scheme in which the intermediate products are dialkyl and trialkyl phosphites and the side product is dialkyl alkylphosphonate is proposed for the process.Key words: Phosphate esters, white phosphorus, electrosynthesis.
- Romakhin, A. S.,Budnikova, Yu. G.,Zaripov, I. M.,Kargin, Yu. M.,Nikitin, E. V.,et al.
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p. 1031 - 1035
(2007/10/02)
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- INSERTION OF CARBENES INTO P-H BONDS. 5. SYNTHESIS OF NEW PHOSPHONATES AND PHOSPHINATES IN REACTIONS CATALYSED BY Cu, Pd, Rh, Ni COMPLEXES
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Cu(OTf)2 and Cu(acac)2 were found to be the most effective catalysts in the reaction of diazo compounds Ph2CN2 (1a), EtOC(O)CHN2 (1b), MeOC(O)CHN2 (1c), MeC(O)CN2C(O)OMe (1d), ClCH2C(O)CHN2 (1e) and CH2N2 (1f) with hydrophosphoryl compounds (MeO)2P(O)H (2a), (t-BuO)2P(O)H (2b), Ph(MeO)P(O)H (2c), (EtO)2P(O)H (2d) and P(O)H (2e) resulting in P-C bond formations.Cu, Pd and Rh acetates and Ni(acac)2 have a much lower efficiency.Chlorines in Cl3CC(O)CH2P(O)(OMe)2 (3k) and Cl2CHC(O)CH2P(O)(OMe)2 (3l) are reduced in the copper catalysed Atherton-Todd reaction.Key words: Catalyst; diazo compound; hydrophosphoryl compound; insertion; phosphonate; phosphinate.
- Polozov, Alexander M.,Mustaphin, Albert H.,Khotinen, Alexander V.
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p. 153 - 160
(2007/10/02)
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- PHOTOLYSIS OF ARYL ESTERS OF TRI- AND TETRACOORDINATED PHOSPHORUS COMPOUNDS
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Upon UV excitation in methanol, some diaryl esters of alkly- or alkenyl phosphonates underwent an elimination of two aryl groups to give biaryls and the corresponding alkyl- or alkenylphosphonic acids.Tris(4-methoxyphenyl) phosphite also underwent a similar elimination to give 4,4'-dimethoxybiphenyl and 4-methoxyphenyl phosphonate.This interesting biaryl elimination was confirmed to proceed via a singlet intramolecular excimer by means of fluorescence spectra and Stern-Volmer analysis.
- Shi, Min,Yamamoto, Kiichi,Okamoto, Yoshiki,Takamuku, Setsuo
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