- The Synthesis and Mechanistic Considerations of a Series of Ammonium Monosubstituted H-Phosphonate Salts
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A series of ammonium monosubstituted H-phosphonate salts were synthesized by combining H-phosphonate diesters with amines in the absence of solvent at 80 °C. Variation of the ester substituent and amine produced a range of ionic liquids with low melting points. The products and by-products were analyzed by spectroscopic and spectrometric techniques in order to get a better mechanistic picture of the dealkylation and formal dearylation observed. For dialkyl H-phosphonate diesters, (RO)2P(O)H (R=alkyl), the reaction proceeds via direct dealkylation with the reactivity increasing in the order R=iPr?1. For the diphenyl H-phosphonate diesters, (PhO)2P(O)H, the dearylation was found to proceed via phenol-assisted formation of a 5-coordinate intermediate, (PhO)3PH(OH), from which P(OPh)3 and water were eliminated. The presence of an equivalent of water then facilitated the formation of P(OH)2OPh and the amine, R'NH2, subsequently abstracted a proton from it to yield [(PhO)PH(O)O]-[R'NH3]+.
- Lee, Keng Lung,Feld, Joey,Hume, Paul,S?hnel, Tilo,Leitao, Erin
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supporting information
p. 815 - 824
(2020/11/30)
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- 31PNMR study on the reactions of amino acids and sugar derivatives with pyrophosphorous acid as a possible prebiotic phosphonylating agent
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Phosphorus is an essential element in living organisms. Evaluating prebiotic processes that lead to phosphorylated biomolecules is an important step toward understanding the origin of life. Schreibersite ([Fe,Ni]3P) is a meteoritic phosphorus mineral which releases various phosphorus species reactive toward biomolecules. We studied the reactions between biomolecules and pyrophosphorus acid (H4P2O5), which is a phosphorous acid derivative released from schreibersite. The reactions between pyrophosphorous acid and molecules having hydroxy groups were carried out under mild alkaline conditions. Notably, some biologically important molecules such as L-serine, L-tyrosine, L-threonine, D-ribose, and D-glyceraldehyde reacted with pyrophosphorous acid to give corresponding phosphonates. These results suggested that if schreibersite and the biomolecules co-existed in the prebiotic earth, they formed the phosphonates which were able to play roles as surrogates or precursors of phosphorylated biomolecules.
- Seio, Kohji,Shiozawa, Takashi,Sugiyama, Daiki,Ohno, Kentaro,Tomori, Takahito,Masaki, Yoshiaki
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p. 905 - 911
(2019/05/21)
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- Catalytic Phosphite Hydrolysis under Neutral Reaction Conditions
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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
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supporting information
p. 4824 - 4827
(2018/05/17)
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- Oxyonium phosphobetaines - Unusually stable nucleophilic catalyst-phosphate complexes formed from H-phosphonates and N-oxides
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Aryl H-phosphonates react with N-oxides to form previously unknown stable zwitterionic oxyonium phosphates comprising an -O-P-O-N+Z atom system. Their structures were confirmed i.e. by X-ray crystal structure analysis, and some mechanisms were proposed for their formation. Stability during storage and reactivity toward nucleophiles points to their possible synthetic applications.
- Materna, Magdalena,Stawinski, Jacek,Kiliszek, Agnieszka,Rypniewski, Wojciech,Sobkowski, Michal
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p. 14448 - 14451
(2016/02/19)
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- Organophosphorus chemistry without PCl3: A bridge from hypophosphorous acid to H-phosphonate diesters
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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)
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- Method and compositions for identifying anti-HIV therapeutic compounds
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Methods are provided for identifying anti-HIV therapeutic compounds substituted with carboxyl ester or phosphonate ester groups. Libraries of such compounds are screened optionally using the novel enzyme GS-7340 Ester Hydrolase. Compositions and methods relating to GS-7340 Ester Hydrolase also are provided.
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- Method and compositions for identifying anti-HIV therapeutic compounds
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Methods are provided for identifying anti-HIV therapeutic compounds substituted with carboxyl ester or phosphonate ester groups. Libraries of such compounds are screened optionally using the novel enzyme GS-7340 Ester Hydrolase. Compositions and methods relating to GS-7340 Ester Hydrolase also are provided.
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- Synthesis of the First Stable Phosphonamide Transition State Analogue
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Three methods were selected for the one-pot synthesis of the fully protected β-fluoroaminophosphonic acids, using the readily accessible N-protected β-fluoroaminals. These were activated by acylation leading, by β-elimination, to a transient N-acylimine immediately trapped by reactive forms of dialkyl phosphites. Avoiding basic conditions, the complete or partial deprotection of these N-protected β-fluoroaminophosphonic esters allowed the synthesis of the free amino acids, their esters, and a racemic β-trifluorophosphonamidic acid. The latter, which represents a transition state analogue formed by the bacterial transpeptidase, is perfectly stable at pH 4.7, contrary to the nonfluorinated compounds.
- De Medina,Ingrassia,Mulliez
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p. 8424 - 8430
(2007/10/03)
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- Aryl H-phosphonates. 7. Studies on the formation of phosphorus-carbon bond in the reaction of trityl and benzyl halides with dialkyl and diphenyl H-phosphonates
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The reactions of H-phosphonate diesters with trityl and benzyl halides were investigated using 31P NMR spectroscopy. It was found that extensive oxidation, which usually accompanies the formation of trityl- or p-nitrobenzylphosphonates from the corresponding alkyl bromides in the Michaelis-Becker reaction, can be considerably suppressed or completely eliminated by reacting p-nitrobenzyl or trityl bromides with diphenyl H-phosphonate in acetonitrile in the presence of DBU.
- Kers, Annika,Stawinski, Jacek,Dembkowski, Leszek,Kraszewski, Adam
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p. 12691 - 12698
(2007/10/03)
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- Studies on aryl H-phosphonates. 3. Mechanistic investigations related to the disproportionation of diphenyl H-phosphonate under anhydrous basic conditions
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Diphenyl H-phosphonate undergoes under anhydrous reaction conditions a base-promoted disproportionation to triphenyl phosphite and phenyl H- phosphonate. On the basis of 31P NMR data the most likely mechanism for this transformation was proposed. In order to substantiate these findings and to get a deeper insight into the chemistry of aryl H-phosphonate esters, we carried out also some studies on activation of phenyl and diphenyl H- phosphonates with various condensing agents. We found that aryl vs alkyl esters of phosphonic acid often follow different reaction pathways during the activation, and this can most likely be traced back to higher electrophilicity of the phosphorus centre and to higher reactivity of the P- H bonds in aryl H-phosphonate derivatives.
- Kers, Annika,Kers, Inger,Stawinski, Jacek,Sobkowski, Michal,Kraszewski, Adam
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p. 9931 - 9944
(2007/10/03)
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- PROPERTIES OF TRIPHENYLPHOSPHITE-MODIFIED RHODIUM CARBONYL CATALYSTS FOR THE HYDROFORMYLATION OF 2-BUTENES
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The factor responsible for the deactivation of a carbonyl triphenylphosphite rhodium hydroformylation catalyst appears to be the formation of a chelate-structure complex with diphenylphosphite, which is the product of partial hydrolysis of the organophosphorus ligand.The deactivating effect of diphenylphosphite can be supressed upon interaction of the H(O)P(OPh)2 and P(OPh)3-modified complex with 2-butenes under hydroformylation reaction conditions.
- Slivinskii, E. V.,Markova, N. A.,Teleshev, A. T.,Korneeva, G. A.,Butkova, O. L.,et al.
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p. 2457 - 2461
(2007/10/02)
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