- A Comparison between Kinetic Parameters from the Synthesis of Tris(p-nitrophenyl)phosphite and Tris(p-nitrophenyl)phosphate Using Reaction Calorimetry
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Tris(p-nitrophenyl)phosphite was prepared by a modification of a "one-pot" methodology developed for the preparation of triaryl phosphates. This exothermic reaction was performed in a Mettler RC-1 calorimeter. The principal aim of this work was to compare the reactivity of phosphorus trichloride and phosphorus oxychloride in their reactions with sodium p-nitrophenoxide. The reaction rate and the reaction rate constant for the synthesis of tris(p-nitrophenyl)phosphite were evaluated and compared to the obtained values for the tris(p-nitrophenyl)-phosphate synthesis. Phosphorus trichloride was found to react faster than phosphorus oxychloride, but the reaction with the phosphorus oxychloride proved to be more exothermic.
- Seiceira, Rafael C.,Machado E Silva, Carlos F. P.,Estevao, Luciana R. M.,Cajaiba Da Silva, Joao F.
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- Synthesis of fluorescent (benzyloxycarbonylamino)(aryl)methylphosphonates
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The synthesis of a library of structurally variable aromatic esters of (benzyloxycarbonylamino)(aryl)methylphosphonic acids is described by means of the Oleksyszyn reaction. The library was enlarged by the application of a Suzuki-Miayra approach and by preparation of mixed esters.
- Vel Gorniak, Michal Gorny,Czernicka, Anna,Mlynarz, Piotr,Balcerzak, Waldemar,Kafarski, Pawel
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supporting information
p. 741 - 745
(2014/05/06)
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- Substituent effects on 31P NMR chemical shifts and 1J P-Se of triarylselenophosphates
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The effect of electron-withdrawing (EW) and electron-releasing (ER) substituents on the 31P NMR chemical shifts and the structural parameters of a series of tris-(p-X-aryl)selenophosphates is reported in this article. Similarly to O-aryl phosphates and O-aryl thiophosphates, EW groups attached to aromatic rings induce a shielding effect on the 31P NMR signal. After a detailed experimental and theoretical analysis, we confirmed that the selenium atom is the main part responsible for the charge density transfer toward phosphorus through a back-bonding effect. The obtained 1JP-Se values for the complete series agree with this observation. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.
- Dominguez, Zaira,Hernandez, Javier,Silva-Gutierrez, Lorena,Salas-Reyes, Magali,Sanchez, Mario,Merino, Gabriel
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experimental part
p. 772 - 784
(2010/07/05)
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- Substituent effects on the 31P NMR chemical shifts of arylphosphorothionates
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Six tris(aryloxy)phosphorothionates substituted in the para position of the aromatic rings were synthesized and studied by 31P NMR, X-ray diffraction techniques and ab initio calculations at a RHF/6-31G** level of theory, in order to find the main structural factors associated with the δ31P in these compounds. As the electron-withdrawing (EW) ability of the substituents was increased, an 'abnormal' shielding effect on δ31P of the arylphosphorothionates was observed. The analyses of the geometrical properties obtained through both experimental and theoretical methods showed that a propeller-type conformation is preferred for the arylphosphorothionates, except in the case of the tris(O-4-methylphenyl) phosphorothionate, since one of the aromatic rings is not rotated in the same direction as the other two in the solid state. The main features associated with the δ31P NMR of compounds 1-6 were a decrease of the averaged O-P-O angle and mainly the shortening of the PS bond length, which is consistent with an increase of the thiophosphoryl bond order as δ31P values go upfield. On the other hand, comparison of the experimental and calculated bond lengths and bond angles involving α bonded atoms to phosphorus of the six compounds suggested that stereoelectronic interactions of the type nπO-σ*PS, nπO- σ*P-OAr and nπS-σ* P-OAr could be present in the arylphosphorothionates 1-6.
- Hernández, Javier,Goycoolea, Francisco M.,Zepeda-Rivera, Denisse,Juárez-Onofre, Josué,Martínez, Karla,Lizardi, Jaime,Salas-Reyes, Magali,Gordillo, Bárbara,Velázquez-Contreras, Carlos,García-Barradas, Oscar,Cruz-Sánchez, Samuel,Domínguez, Zaira
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p. 2520 - 2528
(2007/10/03)
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- A new method for the synthesis of nucleoside 2′,3′-O,O-cyclic phosphorodithioates via aryl cyclic phosphites as intermediates
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The reaction of 5′-O-protected ribonucleosides with tri(4-nitrophenyl) phosphite in the presence of pyridine furnished rapid formation of the corresponding 4-nitrophenyl 2′,3′-O,O-cyclic phosphites which upon sulfhydrolysis, followed by sulfurization of t
- Wenska, Malgorzata,Jankowska, Jadwiga,Sobkowski, Michal,Stawiński, Jacek,Kraszewski, Adam
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p. 8055 - 8058
(2007/10/03)
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