- The Monomeric Metaphosphate Anion in Negative-Ion Chemical-Ionization Mass Spectra of Phosphotriesters
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The monomeric metaphosphate anion, PO3-, was first proposed in 1955 as an intermediate in hyrolysis of phosphomonoesters in aqueous solution.But almost a quarter of a century elapsed before its first direct observation, in the negative-ion chem
- Meyerson, Seymour,Harvan, Donald J.,Hass, J. Ronald,Ramirez, Fausto,Marecek, James F.
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- Electrochemical phosphorylation of arenols and anilines leading to organophosphates and phosphoramidates
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A practical phosphorylation for generating organophosphates and phosphoramidatesviaelectrochemical dehydrogenative cross-coupling of P(O)H compounds with arenols and anilines is disclosed. This method involves using inorganic iodide salts as both redox catalysts and electrolytes in an undivided cell without the addition of oxidants or bases. A preliminary mechanistic study suggests that radicals are not involved in this process. This method is green and eco-friendly and has good functional group tolerance, high yields and broad substrate scope, with the potential for practical synthesis.
- Xu, Pan,Zhong, Zijian,Zhou, Aihua
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supporting information
p. 5342 - 5347
(2021/06/30)
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- Mono- and Bivalent 14-3-3 Inhibitors for Characterizing Supramolecular “Lysine Wrapping” of Oligoethylene Glycol (OEG) Moieties in Proteins
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Previous studies have indicated the presence of defined interactions between oligo or poly(ethylene glycol) (OEG or PEG) and lysine residues. In these interactions, the OEG or PEG residues “wrap around” the lysine amino group, thereby enabling complexatio
- Yilmaz, Elvan,Bier, David,Guillory, Xavier,Briels, Jeroen,Ruiz-Blanco, Yasser B.,Sanchez-Garcia, Elsa,Ottmann, Christian,Kaiser, Markus
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supporting information
p. 13807 - 13814
(2018/09/14)
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- Pd(II)-catalyzed ortho-arylation of aryl phosphates and aryl hydrogen phosphates with diaryliodonium triflates
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Functionalized biaryl compounds were successfully synthesized using phosphates as the ortho-directing group in the Pd(II)/Pd(IV) catalytic cycle.
- Chan, Li Yan,Cheong, Lilian,Kim, Sunggak
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supporting information
p. 2186 - 2189
(2013/06/05)
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- An efficient method for phosphorylation of alcohols: Preparation of porphyrin-derived phosphates
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An effective method for the phosphorylation of phenols and various alcohols including porphyrins bearing hydroxyl groups was developed. The reaction of 6,7-bis(3-hydroxypropyl)-1,3,5,8-tetramethyl-2,4-divinylporphyrin with dialkyl chlorophosphate in the presence of DABCO as both a catalyst and a proton scavenger gave the desired phosphate in 97% yield.
- Pisarek, Sabina,Bednarski, Hubert,Gryko, Dorota
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p. 2667 - 2671,5
(2012/12/12)
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- An efficient method for phosphorylation of alcohols: Preparation of porphyrin-derived phosphates
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An effective method for the phosphorylation of phenols and various alcohols including porphyrins bearing hydroxyl groups was developed. The reaction of 6,7-bis(3-hydroxypropyl)-1,3,5,8-tetramethyl-2,4-divinylporphyrin with dialkyl chlorophosphate in the presence of DABCO as both a catalyst and a proton scavenger gave the desired phosphate in 97% yield. Georg Thieme Verlag KG Stuttgart · New York.
- Pisarek, Sabina,Bednarski, Hubert,Gryko, Dorota
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p. 2667 - 2671
(2013/01/15)
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- Leaving group assistance in the La3+-catalyzed cleavage of dimethyl (o-methoxycarbonyl)aryl phosphate triesters in methanol
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The catalytic methanolysis of a series of dimethyl aryl phosphate triesters where the aryl groups contain an o-methoxycarbonyl (o-CO2Me) substituent (4a-i) was studied at 25°C in methanol containing La 3+ at various concentrations and sspH. Determination of the second-order rate constant for La3+ 2-catalyzed cleavage of substrate 4a (dimethyl (o-methoxycarbonyl) phenyl phosphate) as a function of sspH was assessed in terms of a speciation diagram that showed that the process was catalyzed by La3+ 2(-OCH3)x dimers, where x = 1-5, that exhibit only a 5-fold difference in activity between all the species. The second-order catalytic rate constants (k2La) for the catalyzed methanolysis of 4a-i at sspH 8.7 fit a Bronsted relationship of log k2La= (-0.82 ± 0.11)sspKalg + (11.61 ± 1.48), where the gradient is shallower than that determined for a series of dimethyl aryl phosphates that do not contain the o-CO2Me substituent, log k2La = (-1.25 ± 0.06)s spKalg + (16.23 ± 0.75). Two main observations are that (1) the o-CO2Me group preferentially accelerates the cleavage of the phosphate triesters with poor leaving groups relative to those with good leaving groups and (2) it provides an increase in cleavage rate relative to those of comparable substrates that do not have that functional group, e.g., k2La(dimethyl o-(methoxycarbonyl) phenyl phosphate)/k2La(dimethyl phenyl phosphate) = 60. Activation parameters for the La3+2-catalyzed methanolysis of 4a and dimethyl 4-nitrophenyl phosphate show respective ΔH? (ΔS?) values of 3.3 kcal/mol (-47 cal/mol·K) and 0.7 kcal/mol (-46.5 cal/mol·K). The data are analyzed in terms of a concerted reaction where the catalytic complex (La3+2( -OCH3)x-1) binds to the three components of a rather loose transition state composed of a nucleophile CH3O -, a nucleofuge -OAr, and a central (RO)2P 2+-O- in a way that provides leaving group assistance to the departing aryloxy group.
- Edwards, David R.,Liu, C. Tony,Garrett, Graham E.,Neverov, Alexei A.,Brown, R. Stan
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supporting information; experimental part
p. 13738 - 13748
(2010/01/06)
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- Geometrical photoisomerization of (Z)-cyclooctene sensitized by aromatic phosphate, phosphonate, phosphinate, phosphine oxide and chiral phosphoryl esters
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Aromatic phosphate, phosphonate, phosphinate and phosphine oxide have been used as effective sensitizers for the geometrical photoisomerization of (Z)-cyclooctene (1Z) to its highly strained (E)-isomer (1E). Photosensitizations with phosphate and phosphonate gave moderate photostationary-state E/Z ratios of 0.14-0.17. A comparative study of the fluorescence quenching experiments and kinetic analysis of the product yield demonstrate that the photosensitized isomerization proceeds through a mixed mechanism that involves both singlet and triplet excited states. Triphenylphosphine oxide is not fluorescent and gave a low photostationary-state E/Z ratio of 0.05. Using (-)-menthyl or (-)-bornyl phosphate, phosphonate and phosphinate as chiral sensitizers, the enantiodifferentiating photoisomerization of 1Z was performed to afford optically active 1E in enantiomeric excesses ≤5%.
- Shi, Min,Inoue, Yoshihisa
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p. 2421 - 2427
(2007/10/03)
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- Electronic Structure and 31P NMR Chemical Shift of Substituted Triaryl, Diaryl Methyl and Dimethyl Aryl Phosphates - a Semi-empirical Molecular Orbital Approach
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The 31P NMR chemical shift of triaryl phosphate, diaryl methyl phosphate and dimethyl aryl phosphate series was determined.The δ31P values exhibit an increasing downfield trend when aryl substituents are exchanged for alkyl groups and δ31P values show an increasing upfield trend as the electron withdrawing ability of the substituent in the aromatic ring is increased.Semi-empirical calculations showed an increasing positive charge on phosphorus atom and an increasing phosphoryl bond order when δ31P values go upfield.These results are in good agreement with the effect of "back bonding" from the phosphoryl oxygen to the phosphorus atom. - Keywords: 31P NMR chemical shifts; structural effects; molecular orbitals; triaryl phosphates; diaryl alkyl phosphates; dialkyl aryl phosphates
- Silva, J. F. Cajaiba da,Pedrosa, M. S.,Nakayama, H. T.,Neto, C. Costa
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- A CONVENIENT SYNTHETIC ROUTE TO PHOSPHATE ESTERS FROM PHOSPHITES
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Dialkyl arylphosphate esters have been synthesized in improved yields by the reaction of dicyclohexylamine salts of substituted phenols with dialkyl hydrogen phosphite and carbon tetrachloride.The reaction proceeds through the corresponding phosphorochloridates.
- Purnanand,Batra, B. S.,Pant, B. P.
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p. 1687 - 1688
(2007/10/02)
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- 1,3-CARBANIONISCHE UMLAGERUNGEN: REAKTIONEN VON PHOSPHORSAEURE-o-HALOARYLESTERN MIT METALLEN ZU ARYLPHOSPHONSAEUREDERIVATEN
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o-Bromoaryl esters of phosphoric acid react with magnesium to give arene phosphonic acid derivatives via intermediate Grignard compounds.Similar metallation rearrangement processes may be achieved in the case of o-chloroaryl esters if sodium is applied as
- Heinicke, J.,Boehle, I.,Tzschach, A.
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- Successive Displacements of Phenoxy by Methoxy Groups in Triphenyl Phosphite Ozonide: Mechanism of the Accelerated Singlet Oxygen Formation with Pyridine and Methanol
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The ozonides from triphenyl phosphite, methyl diphenyl phosphite, and phenyl dimethyl phosphite form a series (1-3) which liberate singlet thermally at rates incresing by an order of magnitude for each substitution of methoxy for phenoxy.Trimethyl phosphite ozonide (4) fits in this series, although the very low temperature limit of its stability has not been determined.When triphenyl phosphite ozonide (1) is treated with methanol and pyridine in methylene chloride and yields singlet oxygen at an accelerated rate, the phenyl methyl phosphates 6 and 7 and trimethyl phosphate (8) are produced in a total amount corresponding to the singlet oxygen evolved.The lower the temperature, the greater the predominance of trimethyl phosphate (8) in the product.Each of the mixed phosphite ozonides 2 and 3 is in turn subject to accelerated singlet oxygen formation by the action of methanol and pyridine; in each case the phosphates formed contain at least one more methoxy group than the starting ozonide.These facts establish the mechanism of the accelerated singlet oxygen liberation as a successive displacement of phenoxy by methoxy groups on the initial phosphite ozonide, each newly formed aliphatic-aromatic phosphite ozonide decomposing thermally at its own increased rate.
- Bartlett, Paul D.,Lonzetta, Charles M.
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p. 1984 - 1988
(2007/10/02)
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- Selective phosphorylation process
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A one step process for the preparation of phosphate esters of phenol comprising reacting phenol with a dimethyl disulfide and a trialkyl phosphite.
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