- Way to Enforce Selectivity via Steric Hindrance: Improvement of Am(III)/Eu(III) Solvent Extraction by Loaded Diphosphonic Acid Esters
-
Hybrid donor extractants are a promising class of compounds for the separation of trivalent actinides and lanthanides. Here, we investigated a series of sterically loaded diphosphonate ligands based on bipyridine (BiPy-PO-iPr and BiPy-PO-cHex) and phenant
- Matveev, Petr I.,Huang, Pin-Wen,Kirsanova, Anna A.,Ananyev, Ivan V.,Sumyanova, Tsagana B.,Kharcheva, Anastasia V.,Khvorostinin, Evgenii Yu.,Petrov, Vladimir G.,Shi, Wei-Qun,Kalmykov, Stepan N.,Borisova, Nataliya E.
-
p. 14563 - 14581
(2021/10/12)
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- Reaction of sodium N-benzylideneglycinate with dialkyl chlorophosphites in the presence of water
-
The outcome of reaction of sodium N-benzylideneglycinate containing water in its crystal lattice with dialkyl chlorophosphites depends on the mode of addition of the latter. Upon the simultaneous mixing of the reactants, 1,4-bis[α-(dialkoxyphosphoryl)benz
- Dimukhametov, Mudaris N.,Mironov, Vladimir F.,Islamov, Daut R.,Litvinov, Igor A.,Gnezdilov, Oleg I.,Danilova, Yuliya V.
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p. 107 - 109
(2021/02/16)
-
- Copper-Catalyzed C?P Cross-Coupling of (Cyclo)alkenyl/Aryl Bromides and Secondary Phosphine Oxides with in situ Halogen Exchange
-
An efficient protocol for concurrent tandem halogen exchange/C?P cross-coupling of cycloalkenyl bromides and secondary phosphine oxides has been developed. The catalytic system is based on cheap and air-stable copper(I) iodide as the precatalyst, commercially available N,N’-dimethylethylenediamine as the ligand, and Cs2CO3 or K2CO3 as the base. The use of sodium iodide as an additive reduces the excessive use of organic bromides to near-stoichiometric by promoting the in situ transformation to the corresponding iodides. Diarylphosphine oxides undergo cycloalkenylation with 35–99 % yields and dicyclohexylphosphine oxide with 30–53 % yields. In the case of acyclic alkenyl bromides the cross-coupling products undergo conjugate addition of diphenylphosphine oxide and satisfying yields are observed only for internal olefins. In the case of aryl bromides satisfying yields (43–72 %) are observed only for sterically unhindered arenes or arenes possessing an ortho-directing group. Cycloalkenylphosphine oxides prepared in the cross-coupling reaction undergo base-catalyzed and base-promoted conjugate addition to give bis(phosphinoyl)cycloalkanes.
- Stankevi?, Marek,Wo?nicki, Pawe?
-
supporting information
p. 3484 - 3491
(2021/07/22)
-
- METHOD FOR PRODUCING ORGANOPHOSPHORUS COMPOUND
-
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
- -
-
Paragraph 0085; 0090; 0091; 0094; 0095
(2020/05/02)
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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
-
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
-
supporting information
p. 2916 - 2922
(2019/06/18)
-
- Nickel-Catalyzed Hydrophosphonylation and Hydrogenation of Aromatic Nitriles Assisted by Lewis Acid
-
In this paper, we describe the catalytic hydrophosphonylation of several aromatic nitriles used to synthesize α-aminophosphonates (α-APs) using commercially available trialkyl phosphites (P(OR)3, R=Et, iPr, Bu,) and simple and inexpensive nickel chloride (NiCl2.6H2O) as the catalytic precursor. The use of triethylborane (Et3B) as a Lewis acid (LA) was mandatory in order to successfully perform H-phosphite moiety incorporation at the CN bond of non-activated benzonitriles (BN) derivatives. Interestingly, when a highly activated BN such as 2,3,4,5,6-pentafluorobenzonitrile (BN-g) was employed, it was possible to perform the reaction in the absence of an LA using milder reaction conditions. Also, we found that using HP(O)(OiPr)2 as a starting material afforded the aminobisphosphonate derivative with better selectivity than using the method involving P(OiPr)3 as the initial reagent. Remarkably, when using HP(O)(OiPr)2 with an excess of Et3B, the reaction's selectivity completely changed to yield N-benzyl- benzylimine (BBI) and 2,4,5-triphenylimidazole.
- Islas, Rosa E.,García, Juventino J.
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p. 1337 - 1345
(2019/02/01)
-
- Catalytic Phosphite Hydrolysis under Neutral Reaction Conditions
-
Cationic phosphametallocene-based platinum(II) aqua complexes were used as efficient precatalysts for the hydrolysis of aromatic and aliphatic tertiary phosphites under neutral reaction conditions at room temperature, leading to the selective cleavage of one P-O bond of the phosphite. NMR labeling experiments combined with stoichiometric model reactions and theoretical density functional theory calculations, performed with the appropriate model compounds, shed light on the operative catalytic cycle, which comprises intramolecular water molecule transfer to the cis-coordinated phosphite molecule.
- Oberhauser, Werner,Manca, Gabriele
-
supporting information
p. 4824 - 4827
(2018/05/17)
-
- Synthesis and structure-activity relationships study of α-aminophosphonate derivatives containing a quinoline moiety
-
Two series of α-aminophosphonate derivatives containing a quinoline moiety have been designed and synthesized by introducing bioactive quinoline scaffold to α-aminophosphonate. The in vitro cytotoxic activities of target compounds were first investigated against two human cancer cell lines including Eca109 and Huh7 by MTT assay. Results revealed that most of target compounds exhibited moderate to high antitumor activities against the tested cancer cell lines and some demonstrated more potent inhibitory activities compared with Sunitinib. Among them, compounds 4b2 and 4b4 containing methyl-substituted aniline group were found to be more active than Sunitinib against both of two cancer cell lines, with IC50 in the range of 2.26?μmol/L–7.46?μmol/L.
- Zhu, Xi-Feng,Zhang, Jing,Sun, Shuo,Guo, Yan-Chun,Cao, Shu-Xia,Zhao, Yu-Fen
-
p. 1514 - 1518
(2017/07/17)
-
- Hydrophosphonylation of Alkynes with Trialkyl Phosphites Catalyzed by Nickel
-
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)
-
- Method of preparing kitazin
-
The invention discloses a method for preparing iprobenfos. The method comprises the following steps: (1) by taking phosphorus trichloride and isopropanol as esterification raw materials, performing deacidification reaction, thereby preparing O,O-diisopropyl phosphite; (2) removing residual 2-chloropropane; (3) reacting O,O-diisopropyl phosphite with sulfur and sodium hydroxide at low temperature in the presence of a solvent, thereby generating O,O-diisopropyl sulfo-sodium phosphate; (4) removing the solvent and filtering; (5) reacting O,O-diisopropyl sulfo-sodium phosphate with benzyl chloride, filtering, and separating the liquid, thereby preparing iprobenfos crude raw oil; (6) washing with water, crystallizing, filtering, and removing the solvent, thereby preparing a iprobenfos active compound. According to the method, as the sodium hydroxide is adopted to prepare salt at low temperature, the decomposition of O,O-diisopropyl phosphite is reduced, the impurities are reduced, no ammonia nitrogen wastewater is generated, and as 2-chloropropane of O,O-diisopropyl phosphite is removed, the generation of a byproduct thiophosphoric acid triisopropyl ester is reduced, and the quality of iprobenfos is improved.
- -
-
Paragraph 0053-0055
(2017/06/29)
-
- Oxidative alkoxylation of phosphine in alcohol solutions of copper halides
-
The phosphine oxidation reaction with oxygen in alcohol solutions of copper (I, II) halides is studied. Kinetic parameters, intermediates, and by-products are studied by means of NMR 31Р-, IR-, UV-, and ESR- spectroscopy; and by magnetic susceptibility, redox potentiometry, gas chromatography, and elemental analysis. A reaction mechanism is proposed, and the optimum conditions are found for the reaction of oxidative alkoxylation phosphine.
- Polimbetova,Borangazieva,Ibraimova, Zh. U.,Bugubaeva,Keynbay
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p. 1539 - 1544
(2016/08/26)
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- Synthesis and antitumor activity of α-aminophosphonate derivatives containing thieno[2,3-d]pyrimidines
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Abstract Two series of thieno[2,3-d]pyrimidine derivatives were designed and synthesized, in which bioactive α-aminophosphonate subunits were introduced at the N3 position through an NN bond connection. The in vitro cytotoxic activity of the novel compounds was tested against human esophageal carcinoma cells (EC109), human hepatocarcinoma cells (HepG2), human gastric carcinoma cells (MGC-803), respectively, by the MTT method. The evaluation results revealed that compounds 6mb, 6mf, 6mg, 6nd and 6nh exerted the most potent inhibition against HepG2, MGC-803 and EC109 cells, respectively. In particular, compound 6mg presented excellent inhibitory effect against HepG2 (91.2%) and MGC-803 (94.4%) cells.
- Guo, Yan-Chun,Li, Jing,Ma, Jiao-Li,Yu, Zhi-Ran,Wang, Hai-Wei,Zhu, Wen-Juan,Liao, Xin-Cheng,Zhao, Yu-Fen
-
p. 755 - 758
(2015/08/03)
-
- Novel dialkylphosphorylhydrazones: Synthesis, leishmanicidal evaluation and theoretical investigation of the proposed mechanism of action
-
As part of a program to develop new drugs for the treatment of neglected diseases, new dialkylphosphorylhydrazones were synthesized and evaluated against the trypanosomatid parasites Leishmania braziliensis and Leishmania amazonensis. The synthesis of these compounds proved satisfactory with yields ranging from moderate to good. The most active compounds against L. braziliensis presented IC50 values in the 10-2 μM range, similar to that of the reference drug pentamidine. Two compounds, 4m and 4n, showed a significant dose dependent decrease in the infection index of L. amazonensis infected macrophages and caused a complete healing of nodules and ulcers when tested in vivo against L. amazonensis-infected mice, but the control of parasite burden at the inoculation site was statistically significant only in the case of treatment with 4n. A target fishing (reverse docking) approach using molecular docking with 15 enzymes of L. braziliensis indicated that the probable target of the active compounds was hexokinase, the first enzyme of the glycolytic pathway.
- Da Matta, Carolina Barbosa Brito,De Queiroz, Aline Cavalcanti,Santos, Mariana Silva,Alexandre-Moreira, Magna Suzana,Gon?alves, Vinicius Tomaz,Del Cistia, Catarina De Nigris,Sant'Anna, Carlos Mauricio R.,DaCosta, Jo?o Batista N.
-
-
- Direct conversion of phosphonates to phosphine oxides: An improved synthetic route to phosphines including the first synthesis of methyl JohnPhos
-
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.
-
supporting information
p. 6171 - 6178
(2015/02/19)
-
- Synthesis of H-Phosphonate Intermediates and Their Use in Preparing the Herbicide Glyphosate
-
The esterfication of hypophosphorous acid is followed by reaction with another molecule of alcohol under the action of a nickel catalyst to provide a green method for the preparation of H-phosphonate diesters. This method avoids the need for any stoichiometric chlorine unlike those based on phosphorous trichloride.
- -
-
Paragraph 0046
(2014/10/16)
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- Stability of phosphite coordinated to ruthenium(II) in aqueous media
-
Changes in the reactivity of phosphorus(III) esters, which are promoted by coordination to the ruthenium(II) metal centre, were the focus of this study. Nuclear magnetic resonance data, which were acquired as a function of time, suggest that the phosphite coordination to the ruthenium(II) centre stabilises these molecules in terms of hydrolysis. This stabilisation is greater when the coordination occurs to the trans-[Ru(H2O)(NH3) 4]2+ rather than to the trans-[Ru(NO)(NH3) 4]3+ fragment, and these results are interpreted considering the 4dπ(RuII) → 3dπ(P(III)) back-bonding interactions. The correlation between the data on alkyl phosphite hydrolysis constants in trans-[Ru(NO)(NH3)4P(III)]n + (P(III) = P(OEt)3, P(O)(OEt)2, P(O iPr)3 and P(OBu)3) complexes and the δ13C data show that the hydrolysis of phosphites that are coordinated to Ru(II) preferably occurs via the Michaelis-Arbuzov mechanism. Only the nitrosyl complex, where P(III) = P(OMe)3, did not exhibit this correlation, which suggests that the hydrolysis likely occurs via the Aksnes mechanism in this case.
- Truzzi, Daniela R.,Franco, Douglas W.
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p. 238 - 244
(2014/07/21)
-
- Palladium-catalyzed α-arylation of benzylic phosphonates
-
A new synthetic route to access diarylmethyl phosphonates is presented. The transformation enables the introduction of aromatic groups on benzylic phosphonates via a deprotonative cross-coupling process (DCCP). The Pd(OAc) 2/CataCXium A-based catalyst afforded a reaction between benzyl diisopropyl phosphonate derivatives and aryl bromides in good to excellent isolated yields (64-92%).
- Montel, Sonia,Raffier, Ludovic,He, Yuying,Walsh, Patrick J.
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supporting information
p. 1446 - 1449
(2014/04/03)
-
- Organophosphorus chemistry without PCl3: A bridge from hypophosphorous acid to H-phosphonate diesters
-
A process for the conversion of hypophosphorous acid (H3PO 2, HPA) and alcohols into various H-phosphonate diesters [(RO) 2P(O)H] is described. The new reaction provides a missing bridge between HPA and important H-phosphonates, completely avoiding the use of PCl3. Nickel chloride or nickel on silica catalyze the oxidative phosphorylation of alkyl phosphinates with various alcohols or water. The reaction is atom economic and avoids the formation of waste products. The previous need for both chlorine and base is completely avoided. Esterification of hypophosphorous acid followed by reaction with another molecule of alcohol under the action of a nickel catalyst provides a green method for the preparation of H-phosphonates. This method entirely avoids the need for any stoichiometric chloride unlike those based on phosphorus trichloride. Copyright
- Fisher, Henry C.,Prost, Lucie,Montchamp, Jean-Luc
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p. 7973 - 7978
(2014/01/06)
-
- Method for the esterification of P-O components
-
The present invention is directed to a new method for esterification of P-O components. More specifically, the present invention relates to a new method for esterification of P-O components containing at least one P-O-H functional group, whereby the P-O-H functional group(s) is converted into P-O-R functional group(s). The method according to the invention may find particular use in the manufacture of diesters of phosphorous acid.
- -
-
Paragraph 0038; 0039; 0043
(2013/04/25)
-
- METHOD OF THE SYNTHESIS OF DIALKYL HALOALKYLPHOSPHONATES AND DIALKYL HALOALKYLOXYALKYLPHOSPHONATES
-
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.
- -
-
Page/Page column 15-17
(2012/02/13)
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- Electrophilic trifluoromethylation of S-hydrogen phosphorothioates
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A series of S-hydrogen phosphorothioates have been converted to the corresponding S-trifluoromethyl derivatives upon reaction with the electrophilic trifluoromethylation reagent 1 (trifluoromethyl 1,3-dihydro-3,3-dimethyl-1,2- benziodoxole). Relative rate data were obtained by 19F NMR monitoring of competition experiments and were evaluated by means of the Taft equation. A high positive polar sensitivity factor of 2.55 was found for electron-rich substrates and a negative one of -0.37 for electron-poor ones, implying the involvement of two different rate-determining steps. Furthermore, the reaction was found to be unaffected by steric factors.
- Santschi, Nico,Togni, Antonio
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experimental part
p. 4189 - 4193
(2011/07/31)
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- α-Azido bisphosphonates: Synthesis and nucleotide analogues
-
The first examples of α-azido bisphosphonates [(RO) 2P(O)]2CXN3 (1, R = i-Pr, X = Me; 2, R = i-Pr, X = H; 3, R = H, X = Me; 4, R = H, X = H) and corresponding β,γ- CXN3 dGTP (5-6) and α,β-CXN3 dATP (7-8) analogues are described. The individual diastereomers of 7 (7a/b) were obtained by HPLC separation of the dADP synthetic precursor (14a/b).
- Chamberlain, Brian T.,Upton, Thomas G.,Kashemirov, Boris A.,McKenna, Charles E.
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experimental part
p. 5132 - 5136
(2011/08/09)
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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)
-
- Diastereoselective synthesis of new dialkylphosphorylhydrazones
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A series of 22 dialkylphosphorylydrazones (dialkyl ester, N′-[(1E)-(R1 phenyl)methylene]-phosphorohydrazidic acid), 20 of them new, along with three new N,N′-bis (diisobutylphosphorylthioamide)diamines (bis-[diisobutyl ester), N-thioxomethylene]-, diamine)phosphora-midic acid, were prepared and characterized by IR, 1H NMR, 13C NMR, 31P NMR, and mass spectrometry. The analysis of 1H NMR, 13C NMR, 31P NMR, and NOE spectra confirmed the observation of the single diastereoisomer E in the synthesis of dialkylphosphorylydrazones. The results of a molecular modeling study performed in order to investigate the mechanism of the synthesis of dialkylphosphorylydrazones are in agreement with the experimental results, i.e., the favored formation of diastereoisomer E over Z.
- Rodrigues, Janaina Marques,Sant'anna, Carlos Mauricio R.,Rumjanek, Victor Marcos,Dacosta, Joao Batista Neves
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experimental part
p. 40 - 56
(2010/04/26)
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- Synthesis of O,O-dialkyl 2-oxo-2-(4-(selenomorpho-linosulfonyl)phenylamino) ethylphosphonate
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A series of O,O-dialkyl 2-oxo-2-(4-(seleomorpholinosulfonyl)phenylamino) ethy lphosphonate were synthesized by reactions of 2-chloro-N-(4- (seleomorpholino sulfonyl)phenyl)acetamide with dialkylphosphite in the presence of sodium hydride. The structure of all new compounds has been confirmed by 1H NMR,31P NMR, IR, Mass spectroscopy and elemental analyses. Copyright Taylor & Francis Group, LLC.
- Wang, Fang,Hu, Liming,Li, Xiaopeng,Xu, Xuemei,Du, Hongguang
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scheme or table
p. 610 - 616
(2009/04/11)
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- An efficient synthesis of O,O- di propyl (E)-2-[1-methyl 2-oxopropylidene]phosphorohydrazidothiolate (E) oxime and its analogues: A potential marine toxin
-
An efficient method for the synthesis of Ptychodiscus brevis toxin O,O- di n-propyl (E)-2-[1-methyl 2-oxopropylidene]phosphorohydrazidothiolate (E) oxime (TG-1) and its analogues has been developed using thermally stable and recyclable silica gel and Na2SO4 as a condensing agent and water scavenger, respectively. The compounds were evaluated against fish Rasbora daniconius by determining the LC50 and LC90 values. The results of biological evaluation showed that these compounds have high degree of toxicity. Copyright Taylor & Francis Group, LLC.
- Gupta, Arvind K.,Dubey,Parashar,Kaushik
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scheme or table
p. 1892 - 1910
(2009/08/07)
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- The preparation of dialkyl 1-hydroxyalkylphosphonates in the reaction of trialkyl phosphites with oxonium salts derived from aldehydes or ketones
-
The reaction of trialkyl phosphites with aldehydes or ketones in the presence of hydrogen chloride gives dialkyl 1-hydroxyalkylphosphonates via Arbusov-like reaction of oxonium salts derived from aldehydes or ketones. This reaction is a very convenient instant method for the preparation of dialkyl 1-hydroxyalkylphosphonates with a good yield as an alternative to the well-known Abramov reaction. Georg Thieme Verlag Stuttgart.
- Goldeman, Waldemar,Soroka, Miroslaw
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p. 3019 - 3024
(2008/02/08)
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- Binding of a designed substrate analogue to diisopropyl fluorophosphatase: Implications for the phosphotriesterase mechanism
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A wide range of organophosphorus nerve agents, including Soman, Sarin, and Tabun is efficiently hydrolyzed by the phosphotriesterase enzyme diisopropyl fluorophosphatase (DFPase) from Loligo vulgaris. To date, the lack of available inhibitors of DFPase has limited studies on its mechanism. The de novo design, synthesis, and characterization of substrate analogues acting as competitive inhibitors of DFPase are reported. The 1.73 A crystal structure of O,O-dicyclopentylphosphoroamidate (DcPPA) bound to DFPase shows a direct coordination of the phosphoryl oxygen by the catalytic calcium ion. The binding mode of this substrate analogue suggests a crucial role for electrostatics in the orientation of the ligand in the active site. This interpretation is further supported by the crystal structures of double mutants D229N/N120D and D229N/N175D, designed to reorient the electrostatic environment around the catalytic calcium. The structures show no differences in their calcium coordinating environment, although they are enzymatically inactive. Additional double mutants E21Q/N120D and E21Q/N175D are also inactive. On the basis of these crystal structures and kinetic and mutagenesis data as well as isotope labeling we propose a new mechanism for DFPase activity. Calcium coordinating residue D229, in concert with direct substrate activation by the metal ion, renders the phosphorus atom of the substrate susceptible for attack of water, through generation of a phosphoenzyme intermediate. Our proposed mechanism may be applicable to the structurally related enzyme paraoxonase (PON), a component of high-density lipoprotein (HDL).
- Blum, Marc-Michael,Loehr, Frank,Richardt, Andre,Ruterjans, Heinz,Chen, Julian C.-H.
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p. 12750 - 12757
(2008/02/05)
-
- Preparation of halohydrocarbyl phosphonic acid diesters
-
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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- Reconsideration of the base-free batch-wise esterification of phosphorus trichloride with alcohols
-
Batch-wise esterification of phosphorus trichloride with different alcohols in the absence of base and cleavage of the reaction products by the HCl released in course of the reaction were reinvestigated. The role of the kind of alcohol, mixing order of reagents, temperature, time of reaction, and excursion of gaseous HCl in the proportional composition of the reaction products were studied. Considering the mechanism of esterification and cleavage of the products, the optimized conditions to retain the cleavage process and high-yield production of dialkyl hydrogen phosphonates were determined.
- Fakhraian,Mirzaei
-
p. 401 - 404
(2013/09/05)
-
- Synthesis,in vitro anticancer evaluation, and interference with cell cycle progression of N-phosphoamino acid esters of zidovudine and stavudine
-
A series of N-diisopropylphosphoryl (DIPP) L-amino acid ester prodrugs of zidovudine (AZT) (3a-3e) and stavudine (d4T) (4a-4e) has been prepared. The activity of these compounds against MCF-7 cells (human pleural effusion breast adenocarcinoma cell line)
- Wu,Xiao,Jiang,Fu,Ju,Zhao
-
p. 1797 - 1811
(2007/10/03)
-
- Oxidative alkoxylation of zinc phosphide in alcoholic solutions of copper(II) chloride
-
Oxidative alkoxylation of Zn3P2 with the formation of valuable phosphoric and phosphorous acid esters occurred at a high rate and with a high selectivity in alcoholic solutions of CuCl2 under the action of oxygen at 30-60°C. Depending on the nature of the alcohol, two products were formed, namely, trialkyl phosphates (RO)3PO and dialkyl phosphites (RO)2HPO. Water favored the formation of dialkyl phosphates (RO)2(HO)PO. The kinetics and mechanism of the new catalytic reaction were studied, and the optimal conditions for conducting this reaction were found. The reaction proceeded in a topochemical mode by a separate redox mechanism.
- Dorfman,Ibraimova,Polimbetova
-
-
- Bisphosphonate prodrugs. Synthesis and identification of (1-hydroxyethylidene)-1,1-bisphosphonic acid tetraesters by mass spectrometry, NMR spectroscopy and x-ray crystallography
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The preparation and identification of symmetric, H3CC(OH)[P(O)(OR)2]2, where R=Me, Et, Pr1, Ph, and non-symmetric, H3CC(OH)[P(O)(OR1)(OR2)][P(O)(OR3)(O R4)], where R1=Me, R2=R3=R4=Ph; R1=R2=R3=Ph, R4=Me; R1=R3=Me, R2=R4=Ph; R1=R2=Et, Pr1, Ph and R3=R4=Me: tetraester derivatives of etidronate have been studied. Compounds were prepared from HP(O)(OR1)(OR2) and AcP(O)(OR3)(OR4) species under reflux. Mechanism studies have been made using HP(O)(OCD3)(OPh) and AcP(O)(OMe)(OPh) as starting materials. 1H, 13C, 31P NMR data and the MS fragmentation data in the gas phase are reported. The solid-state structures are given for three of the compounds, where R=Et, Ph and R1=R2=Ph, R3=R4=Me.
- Turhanen, Petri A.,Ahlgren, Markku J.,Jaervinen, Tomi,Vepsaelaeinen, Jouko J.
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p. 115 - 133
(2007/10/03)
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- Reductive cleavage of the halogen-phosphorus, oxygen-phosphorus and phosphorus-phosphorus bonds with alkali metals
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The reduction of phosphorus acid chlorides as well as hypophosphates, pyrophosphates and mixed P(III)-P(V) anhydrides with alkali metals (Li, Na, K) in NH3 liq. / THF solution and potassium naphthalenide was investigated. It was found that this type of phosphorus compounds easily undergo reduction: a) >P(O)Cl to >P(O)H; b) >P(O)P(O)P(O)H; c) >P(O)-O-P(O)P(O)OH and >P(O)H; d) >P(O)-O-PP(O)O- and >P-. The results of our experiments strongly suggest that the mixed P(III)-P(V) anhydride is reduced by potassium naphthalenide in THF with the cleavage of the P(III)-oxygen bond.
- Nycz, Jacek,Rachon, Janusz
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- Spontaneous Lossen Rearrangement of (Phosphonoformyl)hydroxamates. The Migratory Aptitude of the Phosphonyl Group
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(i-PrO)2P(=O)COSEt (1) reacted with NH2OH in pyridine at room temperature to give mainly (i-PrO)2P(=O)NH2 (4). The formation of 4 was interpreted in terms of a spontaneous Lossen rearrangement of (i-PrO)2P(=O)CONHOH (2a) formed in the reaction. A transient 31P NMR signal appearing in the reaction mixture at δ-1.8 was assigned to 2a. Trapping of (i-PrO)2P(=O)N=C=O (5), formed in the reaction of 1 and NH2OH, by cyclohexylamine gave (i-PrO)2P(=O)NHCONHC6H11 (6). Attempted isolation of 6 gave the hydrolyzed product N-cyclohexylurea (7). The reaction of 1 with NH2OMe proceeded slower than that with NH2OH and gave the expected (i-PrO)2P(=O)-CONHOMe (2b), which was isolated and identified. 2b converts slowly to 4 in pyridine at room temperature. In contrast, MeNHOH reacted rapidly with 1 and gave the stable crystalline (i-PrO)2P(=O)CON(Me)OH (2c). The structure of hydroxamates 2 were assigned on the basis of 1H, 13C, and 31P NMR spectral data. This facile Lossen rearrangement is discussed in terms of the unusually high migratory aptitude of the phosphonyl group.
- Salomon, Claudio J.,Breuer, Eli
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p. 3858 - 3861
(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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- Failure of aminophosphonate synthesis due to facile hydroxyphosphonate-phosphate rearrangement
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In a Kabachnik-Fields synthesis of aminophosphonates amines can catalyse the formation of hydroxyphosphonates, and their further rearrangement to phosphates, unabling the formation of aminophosphonates.
- Gancarz,Gancarz
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p. 145 - 148
(2007/10/02)
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- POLYHALOMETHANE REACTIONS WITH PHOSPHITE ANIONS: FLUOROPHILIC REACTIVITY OF PHOSPHORUS
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Di-isopropyl phosphite reacts with bromotrifluoromethane under basic conditions giving a mixture of some seven products.Identification of these by high-resolution NMR and MS shows that 80 percent of all products are formed by displacement of fluorine from
- Blackburn, G. Michael,Guo, Mao-Jun,Taylor, Steven
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p. 139 - 142
(2007/10/02)
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- 31P CIDNP IN THE REACTION OF ZINC DIISOPROPYLDITHIOPHOSPHATE WITH METHYL ETHYL KETONE PEROXIDE AND CUMENE HYDROPEROXIDE IN BENZENE
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The free-radical nature of the reactions of a series of dithiophosphate complexes of zinc with peroxides was established by 31P chemically induced dynamic nuclear polarization (CIDNP).The polarization coefficient, the reaction rate constant, and the nucle
- Gainullin, R. M.,Ismaev, I. E.,Il'yasov, A. V.
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p. 2029 - 2032
(2007/10/02)
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- THE TITANIUM - MEDIATED TRANSESTERIFICATION OF PHOSPHOROUS ESTERS
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Reactions of alcohols diesters in the presence of titanium tetraalkoxides results in a displacement of both or one ester functions by RO groups of an alcohol used.
- Froneman, M.,Modro, A.
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p. 3327 - 3330
(2007/10/02)
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- Acylphosphonates: P-C Bond Cleavage of Dialkyl Acylphosphonates by Means of Amines. Substituent and Solvent Effects for Acylation of Amines
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Studies on the benzoylation of amines of dialkyl benzoylphosphonates (1A-F) were described in detail. Stoichiometric reactions of diethyl benzoylphosphonate (1B) with a variety of amines (2a-i) gave amides as the main products along with diethyl phosphonate (4B) and α-(phosphoryloxy)benzyl phosphonate (5B). The yields of amides increased with the ratio of 1B/2a-i. The use of hindered dialkyl benzoylphosphonates resulted in high yields of amides while the reaction rates decreased markedly. The benzoylations of n-propylamine (2d) with 1B in various solvents having dielectric constants of 1.9-36.7 were conducted. The yields of N-n-propylbenzamide (3d) and 5B were surprisingly almost constant. However, the reaction rates varied as follows. In nonpolar solvents such as n-hexane and cyclohexane benzoylation was remarkably rapid while the benzoylation in methylene chloride was much slower than that in other solvents used. Compound 1B underwent smooth reaction with aliphatic amines but did not react with aromatic amines under the same conditions. Selective N-benzoylation of the bifunctional amine, ethanolamine, was achieved by means of diisopropyl benzoylphosphonate (1C) in tetrahydrofuran. The use of the hindered dialkyl benzoylphosphonate 1C resulted in poorer yields of amides in the case of the reaction with a hindered amine such as diethylamine, but higher yields of amides in the case of primary amines. Addition of triethylamine and 4-(dimethylamino)pyridine (DMAP) slightly accelerated the benzoylation, but yields of amides were similar to those in the absence of the catalysts. Optimum conditions for high yields of amides were proposed for the practical use of dialkyl benzoylphosphonates as the acylating agents in the present reaction.
- Sekine, Mitsuo,Satoh, Masaki,Yamagata, Hikaru,Hata, Tsujiaki
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p. 4162 - 4167
(2007/10/02)
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