- A simple and effective method for phosphoryl transfer using TiCl4 catalysis
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(graph presented) A number of Lewis acids have been evaluated as catalysts for the phosphoryl transfer, the most efficient being TiCl4. Application of this methodology to the phosphorylation of a number of representative target alcohols is presented.
- Jones, Simon,Selitsianos, Dimitrios
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- Organocatalytic phosphorylation of alcohols using pyridine- N -oxide
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Phosphorylation of alcohols by phosphoryl chlorides catalysed by pyridine-N-oxide is reported. The utility of this method is demonstrated through phosphorylation of primary, secondary and a tertiary alcohol as well as phenols under mild reaction conditions and with low catalyst loading (5 mol%).
- Murray, James I.,Woscholski, Rudiger,Spivey, Alan C.
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supporting information
p. 985 - 990
(2015/04/27)
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- Enhanced catalytic decomposition of a phosphate triester by modularly accessible bimetallic porphyrin dyads and dimers
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A series of metalloporphyrin dimers were modularly prepared and shown to catalyze the methanolysis of a phosphate triester, yielding rates that are large compared to the rate of the uncatalyzed reaction. Up to 1300-fold rate acceleration can be achieved v
- Totten, Ryan K.,Ryan, Patrick,Kang, Byungman,Lee, Suk Joong,Broadbelt, Linda J.,Snurr, Randall Q.,Hupp, Joseph T.,Nguyen, Sonbinh T.
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supporting information; experimental part
p. 4178 - 4180
(2012/05/05)
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- Activating water: Important effects of non-leaving groups on the hydrolysis of phosphate triesters
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The high rate of spontaneous hydrolysis of tris-2-pyridyl phosphate (TPP) is explained by the activating effects of the non-leaving ("spectator" ) groups on P-OAr cleavage, and not by intramolecular catalysis. Previous work on phosphate-transfer reactions has concentrated on the contributions to reactivity of the nucleophile and the leaving group, but our results make clear that the effects of the non-leaving groups on phosphorus can be equally significant. Rate measurements for three series of phosphate triesters showed that sensitivities to the non-leaving groups are substantial for spontaneous hydrolysis reactions, although significantly smaller for reactions with good nucleophiles. There are clear differences between triaryl and dialkyl aryl triesters in sensitivities to leaving and non-leaving groups with the more reactive triaryl systems showing lower values for both βLG and βNLG. Intramolecular catalysis of the hydrolysis of TPP by the neighbouring pyridine nitrogens is insignificant, primarily because of their low basicity.
- Kirby, Anthony J.,Medeiros, Michelle,Oliveira, Pedro S. M.,Orth, Elisa S.,Brandao, Tiago A. S.,Wanderlind, Eduardo H.,Amer, Almahdi,Williams, Nicholas H.,Nome, Faruk
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supporting information; experimental part
p. 14996 - 15004
(2012/02/03)
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- Substitution- and elimination-free phosphorylation of functionalized alcohols catalyzed by oxidomolybdenum tetrachloride
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Among 14 oxidometallic species examined for catalytic phosphorylation of the tested alcohols, oxidomolybdenum tetrachloride (MoOCl4) was found to be the most efficient with a negligible background reaction mediated by triethylamine (Et3N). The new catalytic protocol can be applied to the chemoselective phosphorylations of primary, secondary and tertiary alcohols as well as the substitution-free phosphorylations of allylic, propargylic, and benzylic alcohols. Functionalized alcohols bearing acetonide, tetrahydropyranyl ether, tert-butyldimethylsilyl ether, or ester group are also amenable to the new catalytic protocol. The most difficult scenarios involve substitution-free phosphorylations of 1-phenylethanol and 1-(2-naphthyl)ethanol which can be effected in 95 and 90% yields, respectively. ESI-MS, IR, 1H, and 31P NMR spectroscopic analyses of the reaction progress suggest the intermediacy of an alkoxyoxidomolybdenum trichloride-triethylamine adduct such as [(RO)Mo(O)Cl3-Et3N] to be responsible for the catalytic turnover.
- Liu, Cheng-Yuan,Pawar, Vijay D.,Kao, Jun-Qi,Chen, Chien-Tien
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experimental part
p. 188 - 194
(2010/07/03)
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- Hydrolysis of organophosphate esters: Phosphotriesterase activity of metallo-ss-lactamase and its functional mimics
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The phosphotriesterase (PTE) activity of a series of binuclear and mononuclear zinc(II) complexes and metallo-β-lactamase (mβl) from Bacillus cereus was studied. The binuclear complex 1, which exhibits good mβl activity, shows poor PTE activity. In contrast, complex 2, a poor mimic of mβl, exhibits much higher activity than 1. The replacement of Cl - ligands by OH- is important for the high PTE activity of complex 2 because this complex does not show any catalytic activi-ty in methanol. The natural enzyme mssl from B. cereus is also found to be an inefficient catalyst in the hydrolysis of phosphotriesters. These observations indicate that the binding of -lactam substrates at the binuclear zinc(II) center is different from that of phosphotriesters. Furthermore, phospho diesters, the products from the hydrolysis of triesters, significantly inhibit the PTE activity of mβl and its functional mimics. Although the mononuclear complexes 3 and 4 exhibited significant mβl activity, these complexes are found to be almost inactive in the hydrolysis of phosphotriesters. These observations indicate that the elimination of phosphodiesters from the reaction site is important for the PTE activity of zinc(II) complexes.
- Tamilselvi,Mugesh, Govindasamy
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experimental part
p. 8878 - 8886
(2010/11/02)
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- Phosphorylation of alcohols with N-phosphoryl oxazolidinones employing copper(II) triflate catalysis
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(Chemical Equation Presented) Phosphoryl transfer from N-phosphoryl 5,5-diphenyl oxazolidinone is efficiently catalyzed by copper(II) triflate. The utility of this method has been demonstrated in the phosphorylation of representative primary, secondary, tertiary, phenolic, and allylic alcohols. These reaction conditions are significantly milder than employing alkoxides and allow the phosphorylation of biologically relevant molecules.
- Jones, Simon,Smanmoo, Chaiwat
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p. 3271 - 3274
(2007/10/03)
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- N-Phosphoryl oxazolidinones as effective phosphorylating agents
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A number of N-phosphoryl oxazolidinones have been prepared and evaluated, the best being 5,5-diphenyl oxazolidinones, the utility of which was demonstrated in the phosphorylation of a number of representative primary, secondary, tertiary, and phenolic alcohols.
- Jones, Simon,Smanmoo, Chaiwat
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p. 1585 - 1588
(2007/10/03)
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- An improved method for Lewis acid catalyzed phosphoryl transfer with Ti(t-BuO)4
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Several inorganic esters have been evaluated as phosphoryl transfer catalysts. Of these, Ti(t-BuO)4 was found to be the most effective catalyst giving excellent yields of the desired phosphate esters. The loading of the catalyst could be reduced to a little as 5 mol % for a majority of substrates with no loss in the yield of product. This methodology is significantly more versatile than using TiCl4 and is suitable for the phosphorylation of more complex carbohydrates and molecules of biological interest.
- Jones, Simon,Selitsianos, Dimitrios,Thompson, Kate J.,Toms, Steven M.
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p. 5211 - 5216
(2007/10/03)
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- Synthesis of Unsymmetrical Triaryl Phosphates under Phase-Transfer Catalysis
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A Convenient general method for preparing of unsymmetrical triaryl phosphates is elaborated. The influence of the reaction conditions on the yield and purity of the target products is revealed.
- Genkina,Shipov,Mastryukova,Kabachnik
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p. 1742 - 1744
(2007/10/03)
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- Metallomicelles as Catalysts of the Hydrolysis of Carboxylic and Phosphoric Acid Esters
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Lipophilic ligands 2-4 have been synthesized.In the presence of Cu(II) ions, they form metallomicelles that are catalytically active in the cleavage of the p-nitrophenyl esters of acetic, hexanoic, and dodecanoic acids.Catalysis was also observed in the cleavage of p-nitrophenyl diphenyl phosphate.The apparent pKa of the Cu(II)-coordinated hydroxyl of ligand 2a, in the micellar aggregate, is 7.7, as estimated from the rate vs pH profiles for both classes of esters: this suggests that the hydroxyl is involved as a nucleophile in the hydrolytic cleavage, which proved to be a really catalytic process.The ligand bearing the free hydroxyl (2a) is more effective in the cleavage of carboxylate esters than ligands with the methylated alcoholic group (2b) or devoid of it (4); the opposite behaviour is observed in the cleavage of the phosphate triester.A rationale is offered that calls for the difference in the coordination ability to the metal center of phosphate and carboxylate esters.
- Scrimin, Paolo,Tecilla, Paolo,Tonellato, Umberto
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p. 161 - 166
(2007/10/02)
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- HYDROLYSE BASIQUE COMPAREE D'ESTERS ALLOPHANIQUES ET PHOSPHORIQUES EN MILIEU MIXTE ACETONITRILE/EAU FAIBLEMENT AQUEUX; MISE EN EVIDENCE D'UNE ENTITE CATALIQUE, INTERMEDIARE DE LA REACTION ENTRE BASE ET SOLVANT
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Kinetic study of base catalysed hydrolysis in acetonitrile-water mixtures of allophanic esters (models of carboxybiotine) and phosphoric esters shows in the range of low water content (less than 1 molar) an enhancement in rate (103) with a maximum at 0.1-0.3 molar in water.This rate enhancement is ascribed to ground state desolvation and the maximum is interpreted by a change in the rate determining step: leaving group departure in the tetrahedral intermediate is indeed the slow step for the reactions in acetonitrile/water mixture less than 0.1 molar in water.For charged phosphoric esters the rate enhancement from an aqueous medium (pH=10) to organic is larger since as high as 106.On the other hand, in such a medium, an additional catalytic effect is observed; it is shown that it is due to the formation of a reactive species which results from reaction of the base on acetamide when accumulated in the medium from base catalysed hydrolysis of the solvent.
- Monnier, Par E.,Botella, J. M.,Murillo, A.,Klaebe, A.,Perie, J.
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p. 1315 - 1332
(2007/10/02)
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