- EVOLUTION THERMIQUE DE VINYLPHOSPHORANES
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The thermal evolution of aryloxy or enoxyvinylphosphoranes 1 is reported.It leads to spirophosphoranes 2.The yield as well as the reaction time decrease when the ?-deficient character of the aryloxy or enoxy system increases.With very electron withdrawing systems, the main reaction is analogous to the second step of the Arbuzov reaction and gives rise to the vinylphosphonate 6 and to the corresponding aromatic ether 7.When the carboxylate group the nearest to the phosphorus atom is replaced by a phenyl group or an hydrogen atom, no spirophosphorane 2 is obtained.The hydrolysis of compounds 2, under mild condition, leads to a new class of phosphonates 3 and 16.
- Labaudiniere, L.,Burgada, R.
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p. 3521 - 3536
(2007/10/02)
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- YLURES SANS SEL, EVOLUTION EN PHOSPHORANES ET EQUILIBRE YLURE PHOSPHORANE I. SYNTHESE ET STRUCTURE
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Synthesis of new salt-free ylids 9, 12 to 16, 19, 20, 22, 27 and 29 and phosphoranes 10, 17, 18, 21, 23, 30 to 33 by addition of a trivalent phosphorus compound (phosphites and amino-phosphines) 1 to 7 with dimethyl acetylenedicarboxylate in presence of a protic trapping reagent are described.The results are consistent with trapping of carbanionic species.In relation with the cyclic or acyclic structure of the trivalent phosphorus compound and the protic trapping reagent ie: methanol, phenol, carboxylic acid, etc.., several pathways are involved.Clearly, three phenomena are shown: one can obtain an ylid via a phosphorane or conversely a phosphorane via an ylid or an equilibrium phosphorane ylid.Results are dealing with thermodynamic or kinetically controlled reactions.
- Burgada, R.,El Khoshnieh, Y. O.,Leroux, Y.
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p. 1207 - 1222
(2007/10/02)
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- Trapping of carbanionic species synthesis of new salt-free ylids and phosphoranes
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Syntheses of new salt-free ylids and phosphoranes by addition of a trivalent phosphorus compound with dimethylacetylene dicarboxylate in presence of a trapping reagent are described. The results are consistent with trapping of carbanionic species.
- Burgada, Ramon,Leroux, Yves,El Khoshnieh
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p. 925 - 928
(2007/10/02)
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