Environmentally friendly epoxidation of olefins under phase-transfer catalysis conditions with hydrogen peroxide

Autor: Yahdih Mahha, Ahmed Atlamsani, Laurent Salles, Jean-Yves Piquemal, Jean-Marie Brégeault, Emmanuel Briot
Přispěvatelé: Systèmes interfaciaux à l'echelle nanometrique (SIEN), Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Physique Appliquee, Chimie des Surfaces, Interfaces et Catalyse, Université Abdelmalek Essaâdi (UAE), Interfaces, Traitements, Organisation et Dynamique des Systèmes (ITODYS (UMR_7086)), Université Paris Diderot - Paris 7 (UPD7)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-ESPCI ParisTech-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)
Rok vydání: 2007
Předmět:
Zdroj: Journal of Catalysis
Journal of Catalysis, Elsevier, 2007, 2 (249), pp.338-348
Journal of Catalysis, 2007, 2 (249), pp.338-348
ISSN: 0021-9517
1090-2694
DOI: 10.1016/j.jcat.2007.05.001
Popis: International audience; Several catalysis systems, WO3·H2O/H2O2–H2O–H3O+/Q+A−/H3PO4/H2SO4/solvent (Q+A− = Arquad 2HT®, [CH3(n-C8H17)3N]+- Cl−; [CH3(n-C8H17)3N]+HSO−4 , [CH3(n-C8H17)3N]+H2PO−4 ; solvent: CHCl3 or toluene) were used to selectively and efficiently convert olefins to their corresponding epoxides at room temperature. With cyclooctene and using Arquad 2HT® as the phase-transfer agent, there is a synergy when both phosphate and sulfate anions are present in the reaction medium compared with systems using either one or the other. The importance of the tungsten(VI) source is, as found previously, underlined by the strong activity increase when WO3·H2O is used instead of Na2WO4·2H2O, even at room temperature. The influence of the phase-transfer agent Q+A− has been evaluated for the system WO3·H2O/H2O2–H2O–H3O+/Q+A−/toluene. With Q+A− (Q+ = [CH3(n-C8H17)3N]+ and A− = Cl−, HSO−4 , and H2PO−4 ), the best results for the conversion of cyclooctene at room temperature are obtained with [CH3(n-C8H17)3N]+H2PO−4 . 31P NMR experiments show the transfer in the organic phase of the [PO4{W2O2(μ-O2)2(O2)2}2]3− and [HPO4{W2O2(μ-O2)2(O2)2}]2− complexes with H3PO4 and H2PO−4 , whereas only [PO4{W2O2(μ-O2)2(O2)2}2]3− can be identified with the addition of H3PO4/HSO−4 or H2PO−4 /H2SO4. Moreover, acid-sensitive epoxides can be prepared using buffers generated by the addition of sodium hydrogenocarbonate or, preferably, disodium hydrogenophosphate, leading to high selectivities toward the corresponding epoxides. The data show that disodium hydrogenophosphate gives the best results even if the reaction time has to be increased to obtain high conversions. The WO3·H2O/H2O2–H2O/[CH3(n-C8H17)3N]+H2PO−4 /toluene catalysis system can be reused in 5 consecutive runs with no loss in activity.
Databáze: OpenAIRE
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