- Free radical reaction of α-haloalkylphosphonates with alkenes and alkynes: A new approach to modified phosphonates
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A new approach to the synthesis of phosphonates 3 functionalized in the α- and γ-phosphonate positions by alkyl, ethoxy, butoxy, acetoxy, acetyl and cyanide groups and allylphosphonate 6 is described. It is based on the radical reaction of α-halosubstituted phosphonates 1 (X = Cl, Br, I) with the terminally unsubstituted alkenes 2 (1-heptene, ethoxyethene, butoxyethene, acetoxyethene, acrylonitrile, methyl vinyl ketone) and alkyne 5 (hept-1-yne). The reaction involving the tin hydride method (Bu3SnH/AIBN) was more effective with alkenes than with alkynes (40-72% versus 20-30%). With electron-rich alkenes, chloro- and bromomethylphosphonates 1 (X = Cl, Br) gave higher yields than iodomethylphosphonate 1 (X = I). Diethyl methylphosphonate 4, as a reduction product of 1, accompanied 3 and 6 in the above reactions. The yield of 4 could be reduced by optimizing the reaction conditions.
- Balczewski,Mikolajczyk
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- Consecutive approach to alkenes that combines radical addition of phosphorus hydrides with horner-wadsworth-emmons-type reactions
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(Chemical Equation Presented) Addition of diethyl thiophosphite to terminal alkenes, in the presence of a radical initiator, followed by deprotonation of the phosphonothioate and reaction with a ketone, offers a concise one-pot approach to substituted alkenes. This novel method, which can incorporate alkylation or acylation steps, can be applied to the stereoselective formation of sterically hindered tri- and tetrasubstituted alkenes.
- Healy, Mark P.,Parsons, Andrew F.,Rawlinson, James G. T.
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- A solution-based approach to composite dielectric films of surface functionalized CaCu3Ti4O12 and P(VDF-HFP)
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High permittivity CaCu3Ti4O12/ poly(vinylidenefluoride-co-hexafluoropropylene) P(VDF-HFP) nanocomposites were investigated as dielectrics for film capacitors. CaCu3Ti 4O12 was synthesized by two different soft-chemistry methods, namely, decomposition of a citrate precursor and a recently developed lactate precursor to identify a preferable route to nanometer scale spherical particles with an increased interfacial area. A ball-milling step was applied to break particle agglomerates and to enhance particle distribution in the composite films. To improve the wetting of the CaCu3Ti 4O12 oxide particles and the polymer, a variety of surfactants, e.g. carbonic acid, silane, sulfonic acid and phosphonic acid were investigated. A successful oxide surface functionalization was achieved by 2,3,4,5,6-pentafluorobenzyl phosphonic acid, leading to stable bonds and good structural compatibility between the surfactant and the highly fluorinated polymer matrix. The films were prepared from composite dispersions by a spin-coating technique and can be formed out of powders from both precursors, but the citrate method is preferable due to milder synthesis conditions and improved film homogeneity. The use of ball-milled powders as the oxide component results in homogeneous particle distributions even near to the percolation threshold. In addition, such fine-ground particles lead to homogeneous film thickness and decreased film roughness. Dielectric measurements at different frequencies revealed an enhancement in the relative permittivity by a factor of 5 compared to the pure polymer while the dielectric losses remained very low.
- Ehrhardt, Claudia,Fettkenhauer, Christian,Glenneberg, Jens,Muenchgesang, Wolfram,Leipner, Hartmut S.,Diestelhorst, Martin,Lemm, Sebastian,Beige, Horst,Ebbinghaus, Stefan G.
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- Transition metal-free access to 3,4-dihydro-1,2-oxaphosphinine-2-oxides from phosphonochloridates and chalcones through tandem Michael addition and nucleophilic substitution
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A novel and transition metal-free synthesis of 3,4-dihydro-1,2-oxaphosphinine 2-oxides was developed. LiHMDS-mediated tandem Michael addition and nucleophilic substitution of readily available phosphonochloridates and chalcones afforded a variety of valuable 3,4-dihydro-1,2-oxaphosphinine 2-oxides bearing diverse functionalities in excellent yields and satisfactory to good diastereoselectivity (up to 99% yield and up to 99?:?1 dr).
- Fu, Zhicheng,Sun, Simin,Yang, Anjian,Sun, Fang,Xu, Jiaxi
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- Method for preparing n-octylphosphonic acid
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The invention provides a method for preparing n-octylphosphonic acid. The method includes the following steps that firstly, n-octylphosphonic acid ester and concentrated hydrochloric acid are added into a reaction kettle, 98% sulfuric acid is added dropwise, stirring is continuously carried out, after sulfuric acid is completely added dropwise, the temperature is raised to 115-118 DEG C and kept for 25-35 hours, the mixture is naturally cooled to 55-65 DEG C, the materials are discharged from the reaction kettle after reaction, the reacted materials are cooled to 25-35 DEG C and is placed for 12 hours or above at the temperature of 25-35 DEG C, and a n-octylphosphonic acid crude product is obtained through centrifugal separation; secondly, the n-octylphosphonic acid crude product is recrystallized to obtain n-octylphosphonic acid. An acid catalyst used in hydrolysis reaction in the preparing process of n-octylphosphonic acid is a mixture of hydrochloric acid and sulfuric acid, is cheap and easy to obtain, and makes hydrolysis of ester thorough.
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Paragraph 0020
(2016/11/17)
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- Ortho-Trialkylstannyl Arylphosphanes by C-P and C-Sn Bond Formation in Arynes
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A novel and efficient approach to ortho-trialkylstannyl arylphosphanes by the reaction of arynes generated in situ with stannylated phosphanes (R3Sn-PR2) is described. Concurrent C-P and C-Sn bond formation occurs with high yields, and stannylated products are easily transformed into valuable ortho-substituted arylphosphanes. The reaction features high efficiency, good regioselectivity, and excellent practicality.
- Li, Yuanming,Chakrabarty, Shyamal,Mück-Lichtenfeld, Christian,Studer, Armido
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supporting information
p. 802 - 806
(2016/02/27)
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- Non-metallic compd. Bisphosphonic acid crosslinked layered manufacturing method
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PROBLEM TO BE SOLVED: To provide a novel noncrosslinking type layered phosphonic acid metal compound which has high crystallinity and a uniformly introduced multicomponent phosphonic acid and is free of a fluorine atom, and to provide a method for the production of the same.SOLUTION: The method for the production of the noncrosslinking type layered phosphonic acid metal compound includes a reaction step of reacting two or more monophosphonic acids or derivatives thereof having predetermined conditions with a metal source that can generate a hexacoordinated metal atom ion to be a central atom (M) of a metal oxide octahedron upon reaction in the presence of a sulfuric acid catalyst. The noncrosslinking type layered phosphonic acid metal compound obtained by the production method is also provided.
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Paragraph 0117
(2017/01/02)
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- Novel fluorinated dialkylphosphonatocholines: Synthesis, physicochemical properties and antiprotozoal activities against Acanthamoeba spp.
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The synthesis of four new organophosphorous gemini surfactants is presented. They belong to the class of dialkylphosphonatocholines. Tails are represented with two octyl groups both non or partially fluorinated. The synthesis was performed by reaction of alkylphosphonic acids with choline derivatives in the presence of 2,4,6-triisopropylbenzenesulfonyl chloride. The micellar, surface active, and solubilization properties of new surfactants were studied. Antiprotozoal activities were tested against Acanthamoeba lugdunensis and Acanthamoeba quina.
- Luká?, Milo?,Garajová, Mária,Mrva, Martin,Devínsky, Ferdinand,Ondriska, Franti?ek,Kubincová, Janka
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- Radical initiation using borole derivatives
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2-Propylbenzo[d][1,3,2]dioxaborole and related derivatives are shown to initiate a range of radical reactions under mild conditions.
- Montgomery, Isabella,Parsons, Andrew F.,Ghelfi, Franco,Roncaglia, Fabrizio
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p. 628 - 630
(2008/09/16)
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- Generation of phosphorus-centered radicals via homolytic substitution at sulfur
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(Chemical Equation Presented) A novel radical domino process relying on the homolytic cleavage of P-S bonds allows the preparation of phosphorus-containing molecules through addition of P-centered radicals onto olefins. The key step of this reaction is a homolytic substitution on a sulfur atom. The scope of the reaction is broad. Diaminophosphonyl radicals whose reactivity was unknown react smoothly with olefins. Use of tin hydride can be avoided. A radical thiophosphinoylation of triple bonds has been uncovered.
- Carta, Paola,Puljic, Nicolas,Robert, Carine,Dhimane, Anne-Lise,Fensterbank, Louis,Lacote, Emmanuel,Malacria, Max
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p. 1061 - 1063
(2007/10/03)
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- Metallo-phosphorylation of alkenes: a highly regioselective reaction of zirconocene-alkene complexes with chlorophosphate
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Zirconocene-alkene complexes Cp2Zr(CH2{double bond, long}CHR) reacted with chlorophosphate to form zircono-ethylphosphonate with high regioselectivity, which is versatile and could be converted into various functionalized organophosphonates.
- Lai, Chunbo,Xi, Chanjuan,Chen, Weixuan,Hua, Ruimao
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p. 6295 - 6302
(2007/10/03)
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- Hydrophosphorylation of alkenes with dialkyl phosphites catalyzed by Mn(III) under air
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A facile method for the synthesis of organophosphonates from alkenes and dialkyl phosphites was developed by the use of Mn(II) under air. Thus, the reaction of 1-octene with diethyl phosphite in the presence of Mn(OAc) 2 (5 mol %) under air at 90 °C led to diethyl octylphosphonate (78%) and diethyl (2-hexyl)decylphosphonate (6%). Internal alkenes such as cis-2-octene gave a regioisomeric mixture of the corresponding hydrophosphorylation products in 84% yields.
- Tayama, Osamu,Nakano, Atsushi,Iwahama, Takahiro,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 5494 - 5496
(2007/10/03)
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- Phosphonyl, Phosphonothioyl, Phosphonodithioyl, and Phosphonotrithioyl Radicals: Generation and Study of Their Addition onto Alkenes
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The treatment of benzyl dialkyl phosphites and dithiophosphites with benzeneselanyl chloride generates an Arbuzov-type transformation leading to the dialkyl selenophosphates 19a and 19b and to selenophosphorodithioates 21a and 21b. Interaction of these substrates with Lawesson's reagent yields the corresponding selenophosphorothioates 20a and 20b and the selenophosphorotrithioates 22a and 22b. When treated with a radical initiator in the presence of a hydrogen donor and an alkene, all eight phosphorus(V) precursors undergo homolytic cleavage of the P-Se bond to generate the phosphonyl, phosphonothioyl, phosphonodithioyl, or phosphonotrithioyl radicals. Most of these are shown to add onto electron-rich and electron-poor alkenes to deliver the expected adducts in fair to excellent yields. Cyclic precursor 19b displays peculiar behavior and, under the reaction conditions, produces only the corresponding cyclic phosphite. Application of this radical chain process is carried out on furanosyl 3-exo-methylene derivative 37 to diastereoselectively furnish five new 3-phosphonomethyl-, 3-phosphonothiomethyl-, and 3-phosphonodithiomethyl-3-deoxofuranoses 38a-c and 38f,g. The possibility of conducting tandem processes is also discussed through experiments involving (1R)-(+)-α-pinene (39) and diallylamine 41.
- Lopin, Chrystel,Gouhier, Geraldine,Gautier, Arnaud,Piettre, Serge R.
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p. 9916 - 9923
(2007/10/03)
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- Addition of trichloromethyl radicals to alkenes: The use of phosphites as hydrogen-atom donors in intermolecular radical reactions
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Addition of trichloromethyl radicals (generated from BrCCl3 or CCl4) to a variety of alkenes in the presence of hydrogen-atom donors has been explored. The use of phosphites as hydrogen-atom donors was shown to provide a mild, novel and technically clean approach to trichloroalkanes.
- Barks,Gilbert,Parsons,Upeandran
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p. 1719 - 1722
(2007/10/03)
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- Three-Component Coupling of Acylphosphonates and Two Carbonyl Compounds Promoted by Low-Valent Samariums: One-Pot Synthesis of β-Hydroxyphosphonates
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Three-component coupling of acylphosphonates and two carbonyl compounds leading to β-hydroxyphosphonates has been achieved with low-valent samariums. Thus, acylphosphonates reacted with aldehydes in the presence of semicatalytic amounts of samarium metal or SmI2 to give acyloxyphosphonates in good yields. The second coupling reaction of the acyloxyphosphonates with aldehydes or ketones promoted by SmI2 afforded β-hydroxyphosphonates instead of olefins. Moreover, these two reactions could be carried out in one pot.
- Takaki, Ken,Itono, Yuichiro,Nagafuji, Akihiro,Naito, Yoji,Shishido, Tetsuya,Takehira, Katsuomi,Makioka, Yoshikazu,Taniguchi, Yuki,Fujiwara, Yuzo
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p. 475 - 481
(2007/10/03)
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- A new, effective approach for the C-C bond formation utilizing 1-, 2- and 3-phosphonyl substituted radicals derived from iodoalkylphosphonates and n-Bu3SnH/Et3B/O2 system
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A new, practical synthesis of highly substituted phosphonates utilizing 1-, 2- and 3-phosphonyl substituted radicals derived from iodoalkylphosphonates and a catalytic or stoichiometric amounts of the n-Bu3SnH/Et3B/O2 reagent is described.
- Balczewski,Pietrzykowski
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p. 7291 - 7304
(2007/10/03)
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- A free radical approach to functionalization of phosphonates utilizing novel 2- and 3-phosphonyl radicals
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A general method for the phosphonyl C2-C3-C bond formation under the free radical, reductive conditions is described. The new approach is based on the synthesis of novel 2- and 3-phosphonyl radicals 6, 9 derived from the corresponding 2- and 3-halo (X = Cl, Br, I) substituted phosphonates 7, 10 and their reaction with alkenes 4. Functionalized phosphonates 5, 8 possessing the 2+2 and 3+2 elongated carbon chain were obtained in 24-73% yields.
- Balczewski, Piotr,Pietrzykowski, Witold M.
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p. 13681 - 13694
(2007/10/03)
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- STEREOSPECIFIC INTRAMOLECULAR CYCLIZATION FOR ASYMMETRIC SYNTHESIS OF (Rp)- AND (Sp)-ENANTIOMERS OF 2-OCTYL- AND 2-PHENYL-4H-1,3,2-BENZODIOXAPHOSPHORIN 2-OXIDES
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Our earlier studies established that: 1) 2-octyl- and 2-phenyl-4H-1,3,2-benzodioxaphosphorin 2-oxides (octyl- and phenyl-BDPOs) induce delayed neuropathy in adult hens at 3 and 200 mg/kg, respectively; 2) phenyl-BDPO also significantly potentiates the acute toxicity of the insecticide malathion to mice; 3) the (Rp) and (Sp) enantiomers of these compounds, resolved on a mg scale by chiral HPLC, differ in potency by 92- and 137-fold, respectively, as inhibitors of neuropathy target esterase.In order to further study the stereospecificity in their toxic effects, the individual enantiomers of octyl- and phenyl-BDPOs are prepared here be a general method of asymmetric synthesis from the corresponding TLC-resolved diastereomeric precursors (Rp)- and (Sp)-methyl N- L-prolinates through acid-catalyzed intramolecular cyclization.This occurs under mild conditions in high yields and involves inversion of configuration at phosphorus.HPLC with the CHIRALCEL OC column established their absolute configurations, based on a previously-published assignment, and 97-100percent e.e. for (Rp)- and (Sp)-octyl- and phenyl-BDPOs. Key words: Asymmetric synthesis, 1,3,2-benzodioxaphosphorin 2-oxide, cyclization, NTE inhibitors, L-propinates, stereochemistry.
- Wu, Shao-Yong,Casida, John E.
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p. 177 - 184
(2007/10/02)
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- Organophosphonic acids or esters containing an epoxy group
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A method for protecting the surface of a metal surface which comprises applying to said surface an organophosphorus compound of the formula STR1 wherein A IS 0 OR 1 R is a branched or unbranched chained bivalent alkylene radical of 1 to 12 carbon atoms which is substituted or unsubstituted and can contain in the chain structure --O--, --S--, STR2 R' is a branched or unbranched alkyl radical of 1 to 12 carbon atoms which can be halogen substituted and can contain in the chain structure STR3 X is an epoxy ring, halogen, alkylene, carboxylic acid ester residue, amino, isocyanato, isothiocyanato, urea, thiourea, urethano, alkyl substituted thio radical or the radical or a heterocyclic ring containing O, S or N in the ring structure; a new organophosphorus compounds having the formula set forth above and more particularly defined by specific chemical structures.
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