53282-12-5Relevant academic research and scientific papers
A two-step ball milling method synthesizes and purifies α,β-unsaturated esters
Shearouse, William C.,Korte, Chelsea M.,Mack, James
experimental part, p. 598 - 601 (2011/05/08)
Over the last decade, solvent-free methods have been gaining interest as replacements for traditional organic chemistry techniques. While solvent-free methods are well known for many processes, a simple, solvent-free purification procedure that supplements them does not exist. We report the solvent-free synthesis of α,β-unsaturated esters using a solvent-free Horner-Wadsworth-Emmons (HWE) reaction using high-speed ball milling (HSBM). We were able to perform the HWE reaction on a variety of aldehydes, and isolate their respective a,b-unsaturated esters in high yields, purities, and diastereoselectivities. The Royal Society of Chemistry.
One-pot Wittig reaction for the synthesis of α,β-unsaturated esters using highly basic magnesium/lanthanum mixed oxide
Kantam, M. Lakshmi,Kumar, K.B. Shiva,Balasubramanyam,Venkanna,Figueras
experimental part, p. 10 - 14 (2010/10/04)
Highly basic Mg/La mixed oxide (Mg/La MO) is an effective heterogeneous base, at room temperature for the one-pot Wittig reaction involving aldehyde, α-halo esters and triphenylphosphine to afford α,β-unsaturated esters in good yields with high E-stereoselectivity. Mg/La mixed oxide was recovered quantitatively by simple filtration and reused. The basic properties of Mg/La mixed oxide have been compared to those of nanocrystalline magnesium oxide using the microcalorimetric adsorption of CO2, and the reactivity for Wittig reactions. Mg/La mixed oxide is a stronger base than magnesium oxide (MgO) but shows a much smaller number of sites. Hammett correlations have been determined for both bases and show that the reaction is base mediated, with values of ρ = 1.7 for Mg/La mixed oxide, and 1.1 for nanocrystalline magnesium oxide, and a compensation effect can then be observed.
REACTIONS DE WITTIG-HORNER ET DE TRANSESTERIFICATION EN UNE OPERATION PAR ACTIVATION ANIONIQUE DE LIAISONS C-H ET O-H EN MILIEU HETEROGENE CARBONATE DE POTASSIUM/ALCOOL
Mouloungui, Z.,Elmestour, R.,Delmas, M.,Gaset, A.
, p. 1219 - 1232 (2007/10/02)
The Wittig-Horner reaction carried out in various alcohols is accompanied by transesterification of the alkyl radical of the α,β-ethylenic ester formed.The occurrence of these two reactions in the same reaction medium is affected by the behavior of: i) the alcohol (solvent and reagent), ii) potassium carbonate (reagent and catalyst).The propensity for the two reactions to occur was found to depend on the polarity of the alcohol.Protic alcohols speeded both the Wittig-Horner and the subsequent transesterification reaction.Both reactions were quantitative despite the use of non-stoichiometric amounts of potassium carbonate.Regeneration in situ of the solid base observed in aprotic medium was markedly enhanced under these reaction conditions.The mechanism proposed for these two reactions incorporates this regeneration process.
SYNTHESIS OF α,β-ETHYLENIC ESTERS IN A HETEROGENOUS SOLID-LIQUID MEDIUM. II - A TRANSESTERIFICATION REACTION LINKED TO A WITTIG-HORNER REACTION IN A PROTIC MEDIUM
Mouloungui, Zephirin,Delmas, Michel,Gaset, Antoine
, p. 491 - 494 (2007/10/02)
The condensation reaction of ethyl or methyl phosphonates with variously functionnalysed aldehydes in the presence of solid potassium carbonate in alcoholic media leads to the direct formation of E α,β unsaturated esters.The alkyl, aryl or heteroaryl substituents of the double bond are provided by the aldehyde and the solvent.The method used involves a solid-liquid transfer process.
