- Synthesis of Long-Chain n-Alkylphosphonic Acids by Phosphonylation of Alkyl Bromides with Red Phosphorus and Superbase under Micellar/Phase Transfer Catalysis
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Long-chain n-Alkylphosphonic acids, AlkP(O)(OH)2, are synthesized in up to 91 % yield (mostly 40–60 %) by straightforward phosphonylation of alkyl bromides (AlkBr, Alk=C4–C18) with red phosphorus (Pn) in the multiphase KOH/H2O/toluene system in the presence of 2–10 mol % of cetyltrimethylammonium bromide (CTAB), acting as a micellar/phase transfer catalyst and as a generator/transporter of superbasic hydroxide anions, the intermediate potassium phosphinates being in situ oxidized/neutralized by nitric acid. The key steps of the phosphonylation mechanism are the P?P bond cleavage of Pn polymeric molecules by superbasic ?OH anions, dissolved in the CTAB micelles, and phase transfer of polyphosphide anions to the organic phase and their alkylation with AlkBr.
- Kuimov, Vladimir A.,Malysheva, Svetlana F.,Belogorlova, Natalia A.,Albanov, Alexander I.,Gusarova, Nina K.,Trofimov, Boris A.
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supporting information
p. 1596 - 1602
(2021/03/03)
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- Structural and vibrational characteristics of amphiphilic phosphonate salts
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1-Decylphosphonic acid (1), ammonium 1-decylphosphonate (NH 4C10H21PO3H) (2), ethylenediaminium 1-decylphosphonate 1,5 hydrate (enH2C10H 21PO3·1.5H2O) (3) and calcium 1-decylphosphonate (Ca(C10H21PO3H)2) (4) were prepared and characterized by IR and Raman spectroscopy. The structures of 2 and 3 were determined by single crystal X-ray diffraction analysis. Compound 2 crystallizes in the P1? space group of triclinic system with two molecules in the asymmetric unit cell whereas compound 3 crystallizes in C2/c space group of monoclinic system with four molecules in the unit cell and both exhibit layered supramolecular structures generated by ionic interaction, H-bonding and alkyl chain interdigitation in the case of 3. The FT-IR and Raman spectra have been assigned in the range 4000-500 cm-1 for all compounds, and reveal the trans conformation of alkane chain in all compounds.
- Boczula, Dorota,Ca?y, Alicja,Dobrzyńska, Danuta,Janczak, Jan,Zoń, Jerzy
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experimental part
p. 220 - 226
(2012/03/08)
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- Supercritical hydrothermal synthesis of carboxylic acid-surface- functionalized TiO2 nanocrystals: PH sensitive dispersion and hybridization with organic compounds
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Surface-functionalized TiO2 (anatase) nanocrystals (NCs) (avg. d=6.7±1.6nm) were synthesized by a supercritical hydrothermal method. A phosphonic acid derivative was used as surface modifier of TiO2 NCs. It was verified that the phosphonic acids were bound to the surface of TiO 2 with very strong binding energy. The TiO2 NCs also exhibited extraordinarily high chemical stability. Such a strong binding between the phosphonic acid modifier and TiO2 had not been obtained by any other methods. The TiO2 NC showed sharp pH sensitive dispersion. Because of the functional as well as stable surface modifier layer, further manipulations on the surface using chemical reagents could be possible.
- Arita, Toshihiko,Moriya, Ken-Ichi,Minami, Kimitaka,Naka, Takashi,Adschiri, Tadafumi
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supporting information; experimental part
p. 961 - 963
(2011/01/05)
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- Dealkylation of dialkyl phosphonates with boron tribromide
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Boron tribromide cleanly and quantitatively converts dimethyl-, diethyl-, diisopropyl-, and ditertiobutyl phosphonates RP(O)(OR')2 into the corresponding phosphonic acids RP(O)(OH)2 via methanolysis. The use of boron tribromide is compatible with a variety of functionalities in the R group.
- Gauvry,Mortier
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p. 553 - 554
(2007/10/03)
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- Phosphorus containing compounds as antihypercholesterolemic and antiatherosclerotic agents
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Novel phosphorus containing compounds are described, as well as methods for the preparation and pharmaceutical composition of same, which are useful in preventing the intestinal absorption of cholesterol and thus are useful in the treatment of hypercholesterolemia and atherosclerosis.
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- Process for preparing phosphonic acids
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A process for preparing phosphonic acids of the structure STR1 wherein R1 is lower alkyl, aryl, cycloalkyl or arylalkyl, and R2 is H, benzyl or STR2 by oxidizing the corresponding phosphonous acid STR3 employing as the oxidizing agent potassium permanganate or sodium periodate.
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- Phosphonate Complexes. Part 6. Influence of Steric Effects, Solvation, and Chelation on Stability
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The interaction of some phosphonic acids RPO(OH)2, chosen to introduce different controlling factors (R=But, cyclo-C6H11, pH, n-C10H21, Me2NCMe2, CH2SEt, CH2CH2CO2(-)), with Ca(II) and Cu(II) has been investigated by potentiometry at 25 deg C, I=0.1 mol dm-3 (K).The selection of the species and the refinement of the stability constants illustrates the applicability of a new version of the program MUCOMP.Examination of linear free-energy plots indicates that factors other than polar effects are of significance, i.e. chelate formation with the potentially bidentate ligands and particularly solvation effects which preferentially stabilize the complexes of α- branched-chain phosphonates.Other features (steric hindrance, predominance of some microscopic forms) are discussed.
- Wozniak, Michel,Nowogrocki, Guy
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p. 2423 - 2428
(2007/10/02)
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