2745-17-7Relevant articles and documents
EPOXYDATION EN MILIEU HETEROGENE SOLIDE-LIQUIDE FAIBLEMENT HYDRATE II - Role de l'eau et schema reactionnel
Borredon, M. E.,Delmas, M.,Gaset, A.
, p. 1073 - 1078 (1988)
The reactional mechanism of the epoxide reaction is studied in a slightly hydrated solid-liquid medium throughout the formation of sulfonium ylide and betaine as well as its transformation into epoxide.The reaction three main steps take place at the interface of the solid-liquid system.They depend on the initial hydration of the reactional medium and the compatibility of the molecular interactions between sulfonium salt and the considered base.The study of secondary reactions likely to appear in this experimental conditions allowed to minimize them which induces epoxide selective formation.An overall reactional scheme taking into account the different elements is proposed.
EPOXYDATION EN MILIEU HETEROGENE SOLIDE-LIQUIDE FAIBLEMENT HYDRATE I : ETUDE DES INTERACTIONS MOLECULAIRES : SEL DE SULFONIUM-BASE
Borredon, M. E.,Sinisterra, J. V.,Delmas, M.,Gaset, A.
, p. 4141 - 4146 (1987)
Structural analysis of the solid-liquid interface topography in relation to the reaction of the sulfonium salt considered and furfural allows definition of the nature of the acid-base interactions that result predominately in formation of the 2-furyl oxiran.Moreover the study made with KOH H2O ; Ba(OH)2 0,8 H2O and K2CO3 1,5 H2O in the solid state pointed out that compatibility between the crystalline lattice of the solid phase and the sulfonium salt structure is critical in order to effect reaction.This important point seems to dominate formation of the ylide, its stability and its subsequent condensation with the carbonyl derivative to give the epoxide.
Solvents as Phase-transfer Catalysts in Reactions initiated by Solid Bases
Bentley, T. William,Jones, Ray V. H.,Larder, Annette H.,Lock, Stephen J.
, p. 2309 - 2310 (2007/10/02)
For reactions initiated by solid bases (e.g. potassium hydroxide, sodium hydroxide, potassium carbonate), solvents (e.g. water, ButOH, polyethylene glycol, MeCN, Me2SO) may act as solid-liquid phase transfer catalysts (e.g. for C-H, N-H or O-H alkylation by alkyl halides, or epoxidation by sulfonium or sulfoxonium salts).
Homologation of furfural and derivatives to furylacetaldehydes
Brochet,Syssa,Mouloungui,Delmas,Gaset
, p. 1735 - 1741 (2007/10/02)
The homologation of furfural 1a and methyl 3-(5-formyl-2-furyl) propenoate 1b or ethyl 3-(5-formyl-2-furyl) propenoate 1c to the corresponding furylacetaldehydes was carried out in two stages: i) preparation of the furan epoxides from 1a, 1b, 1c. ii) cleavage and rearrangement of the epoxides on sepiolite. Sepiolite is a convenient catalyst for this last stage involving substrates as labile as the furan epoxides.
Epoxide Synthesis in Interfacial Solid-Liquid Conditions
Borredon, E.,Clavellinas, F.,Delmas, M.,Gaset, A.,Sinisterra, J. V.
, p. 501 - 504 (2007/10/02)
In this paper an analysis of the factors responsible for discrimination among differing structures of organic reagents by the microcrystalline structure of solids is presented.As a vehicle of this study, the epoxide synthesis using three sulfur ylide precursors (sulfonium and sulfoxonium salts) and four microcrystalline solids was investigated.Neither the surface area nor the number of active sites at the solid surface control the epoxide yield.It appears that the cell lattice of the solid determines the ylide structure, its nucleophilicity, and thus the reaction yield.
RELATIONS RELATIVITE/STRUCTURE DANS LES REACTIONS EFFECTUEES EN MILIEU HETEROGENE SOLIDE/LIQUIDE FAIBLEMENT HYDRATE
Borredon, M. E.,Mouloungui, Z.,Delmas, M.,Gaset, A.
, p. 479 - 486 (2007/10/02)
The interdependence between reactivity and structure of chemical species which determines the evolution of reactions by anionic activation in weakly hydrated heterogeneous medium is discussed for furfural transformation into the corresponding epoxides and ethylenic esters.Particular attention is paid to the function of the crystalline structure of solid phase at the solid/liquid interface.
EPOXYDATION EM MILIEU HETEROGENE SOLIDE-LIQUIDE FAIBLEMENT HYDRATE : ETUDE DE LA REACTION AUTOUR DE LA STRUCTURE DU SEL DE SULFONIUM
Borredon, M.E.,Delmas, M.,Gaset, A.
, p. 3945 - 3954 (2007/10/02)
Epoxide formation by sulphur ylid insertion into aldehydes under heterogeneous conditions in the presence of small quantities of water is described.Trimethylsulphonium and S-methylthiolanium bromide and iodide have been studied.For all alkyl substituents the bromide gives better results than the iodide, this is interpreted in terms of the reaction mechanisms.Under optimum conditions high yields of epoxides are obtained.
