5076-63-1Relevant academic research and scientific papers
Electrochemical phosphorylation of arenols and anilines leading to organophosphates and phosphoramidates
Xu, Pan,Zhong, Zijian,Zhou, Aihua
supporting information, p. 5342 - 5347 (2021/06/30)
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.
LiI/TBHP Mediated Oxidative Cross-Coupling of P(O)–H Compounds with Phenols and Various Nucleophiles: Direct Access to the Synthesis of Organophosphates
Anitha, Thippani,Ashalu, Kashamalla Chinna,Sandeep, Mummadi,Mohd, Aabid,Wencel-Delord, Joanna,Colobert, Francoise,Reddy, Kallu Rajender
, p. 7463 - 7474 (2019/12/03)
An efficient and mild method for the direct phosphorylation of phenols, alcohols, and amines with P(O)–H has been reported by LiI/TBHP mediated oxidative cross-coupling reaction. Moreover, this protocol extended to β-keto esters for the synthesis of enol phosphates using H-phosphonates. Notably, this developed method applied for the synthesis of organopesticides such as paraoxon, cyanophos, and methyl parathion. The key features of this protocol are mild conditions, short reaction time, good functional group tolerance, and broad substrate scope.
Transition State Analysis of the Reaction Catalyzed by the Phosphotriesterase from Sphingobium sp. TCM1
Bigley, Andrew N.,Xiang, Dao Feng,Narindoshvili, Tamari,Burgert, Charlie W.,Hengge, Alvan C.,Raushel, Frank M.
, p. 1246 - 1259 (2019/03/07)
Organophosphorus flame retardants are stable toxic compounds used in nearly all durable plastic products and are considered major emerging pollutants. The phosphotriesterase from Sphingobium sp. TCM1 (Sb-PTE) is one of the few enzymes known to be able to hydrolyze organophosphorus flame retardants such as triphenyl phosphate and tris(2-chloroethyl) phosphate. The effectiveness of Sb-PTE for the hydrolysis of these organophosphates appears to arise from its ability to hydrolyze unactivated alkyl and phenolic esters from the central phosphorus core. How Sb-PTE is able to catalyze the hydrolysis of the unactivated substituents is not known. To interrogate the catalytic hydrolysis mechanism of Sb-PTE, the pH dependence of the reaction and the effects of changing the solvent viscosity were determined. These experiments were complemented by measurement of the primary and secondary 18-oxygen isotope effects on substrate hydrolysis and a determination of the effects of changing the pKa of the leaving group on the magnitude of the rate constants for hydrolysis. Collectively, the results indicated that a single group must be ionized for nucleophilic attack and that a separate general acid is not involved in protonation of the leaving group. The Br?nsted analysis and the heavy atom kinetic isotope effects are consistent with an early associative transition state with subsequent proton transfers not being rate limiting. A novel binding mode of the substrate to the binuclear metal center and a catalytic mechanism are proposed to explain the unusual ability of Sb-PTE to hydrolyze unactivated esters from a wide range of organophosphate substrates.
Enantioselective and Regioselective Hydroetherification of Alkynes by Gold-Catalyzed Desymmetrization of Prochiral Phenols with P-Stereogenic Centers
Zheng, Yin,Guo, Linna,Zi, Weiwei
supporting information, p. 7039 - 7043 (2018/11/24)
The gold(I)-catalyzed enantioselective hydroetherification of alkynes was achieved via desymmetrization of prochiral bisphenols bearing P-stereogenic centers. (S)-DTBM-Segphos(AuCl)2/AgNTf2 proved to be a highly efficient catalyst system for this transformation, affording P-chiral cyclic phosphine oxides in good yields with high enantioselectivities (with up to 99% ee). The same catalyst system allowed for the enantioselective desymmetrization of dialkynes. Synthetic transformations of the cyclization products afforded other P-chiral molecules with high enantiospecificity.
Nucleophilic substitution reactions of diethyl 4-nitrophenyl phosphate triester: Kinetics and mechanism
Castro, Enrique A.,Ugarte, Daniela,Rojas, M. Fernanda,Pavez, Paulina,Santos, Jose G.
supporting information; experimental part, p. 708 - 714 (2012/08/08)
The reactions of diethyl 4-nitrophenyl phosphate (1) with a series of nucleophiles: phenoxides, secondary alicyclic (SA) amines, and pyridines are subjected to a kinetic study. Under excess of nucleophile, all the reactions obey pseudo-first-order kinetics and are first order in the nucleophile. The nucleophilic rate constants (kN) obtained are pH independent for all the reactions studied. The Bronsted-type plot (log kN vs. pKa nucleophile) obtained for the phenolysis is linear with slope β=0.21; no break was found at pKa 7.5, consistent with a concerted mechanism. The Bronsted-type plots for the SA aminolysis and pyridinolysis are linear with slopes β=0.39 and 0.43, respectively, also suggesting concerted processes. The concerted mechanisms for the latter reactions are proposed on the basis of the lack of break in the Bronsted-type plots and the instability of the hypothetical pentacoordinate intermediates formed in these reactions.
Monitoring the phosphorylation of phenol derivatives with diethyl chlorophosphate in liquid-liquid and solid-liquid phase by in situ fourier transform infrared spectroscopy, part II
Keglevich, Gyoergy,Puskas, Reka Eszter,Gruen, Alajos,Csontos, Istvan,Greiner, Istvan
experimental part, p. 2333 - 2340 (2011/01/12)
The reaction of 4-chlorophenol and 4-nitrophenol with diethyl chlorophosphate carried out in a liquid-liquid and solid-liquid two phase system, respectively, was monitored by in situ Fourier transform IR spectroscopy. Copyright Taylor & Francis Group, LLC.
Mechanistic studies of la3+- And Zn2+-catalyzed methanolysis of aryl phosphate and phosphorothioate triesters. Development of artificial phosphotriesterase systems
Liu, Tony,Neverov, Alexei A.,Tsang, Josephine S.W.,Brown, R. Stan
, p. 1525 - 1533 (2007/10/03)
The methanolyses of a series of O,O-diethyl O-aryl phosphates (2,5) and O,O-diethyl S-aryl phosphorothioates (6) promoted by methoxide and two metal ion systems, (La3+)2(-OCH3)2 and 4:Zn2+:-OCH3 (4 = 1,5,9- triazacyclododecane) has been studied in methanol at 25°C. Bronsted plots of the log k2 values vs. sspKa for the phenol leaving groups give βlg values of -0.70. -1.43 and -1.12 for the methanolysis of the phosphates and -0.63, -0.87 and -0.74 for the methanolysis of the phosphorothioates promoted by the methoxide, La 3+ and Zn2+ systems respectively. The kinetic data for the metal-catalyzed reactions are analyzed in terms of a common mechanism where there is extensive cleavage of the P-XAr bond in the rate-limiting transition state. The relevance of these findings to the mechanism of action of the phosphotriesterase enzyme is discussed. The Royal Society of Chemistry 2005.
Dephosphorylation of paraoxon by hydroxamate ions in micellar media
Ghosh, Kallol K.,Satnami, Manmohan Lal,Sinha, Daliya
, p. 9103 - 9105 (2007/10/03)
The rate-surfactant concentration profiles for the reaction of the insecticide paraoxon with hydroxamate ions (R(CO)?NHO-, R = CH3, R = C6H5, R = 2-HOC6H 4) in aqueous solutions of cetyltri
A convenient method for the phosphorylation of phenols with diethyl cyanophosphonate
Guzman, Angel,Diaz, Eduardo
, p. 3035 - 3038 (2007/10/03)
Phosphorylation of phenols with diethyl cyanophosphonate in methylene chloride solution at 0°C is an easy, rapid and good yielding reaction.
