68332-36-5Relevant academic research and scientific papers
Acylation of dimethyl maleate photocatalyzed by decatungstate anion: insights into the hydrogen atom transfer reaction mechanism
Martínez, Juan Pablo,Rivera-Avalos, Ernesto,Vega-Rodríguez, Sarai,de Loera, Denisse
, p. 2061 - 2073 (2017/12/06)
Polyoxometalates arise as significant catalysts in the field of organic chemistry due to their diverse properties and functions. Recent progress based on experimental evidence and density functional theory (DFT) calculations provides valuable information to demystify the chemistry of decatungstate anion, W10O32 4?. Particularly, functionalization of aldehydes by homolytic C–H bond cleavage can be efficiently achieved when it is catalyzed by this polyoxometalate. Two reaction mechanisms have been formulated to account for the role of W10O32 4? in organic chemical reactions: the single electron transfer and the hydrogen atom transfer (HAT) mechanisms. In this contribution, the HAT pathway for the acylation of dimethyl maleate is experimentally and quantum-chemically explored in detail. Results based on DFT calculations under the unrestricted formalism suggest that the acylation occurs in a barrierless process upon the formation of the lowest-in-energy triplet excited state of W10O32 4?. These outcomes agree well with the experimental evidence since the acylated adduct was produced at a 90% yield; in this regard, side reactions like radical couplings and decarbonylation resulted in less competitiveness. The current work may therefore help in the comprehension of the mechanistic details leading to the synthesis of organic compounds photocatalyzed by polyoxometalates, even under solar radiation.
Amino functionalized chitosan as a catalyst for selective solvent-free self-condensation of linear aldehydes
Jose, Tharun,Sudheesh,Shukla, Ram S.
experimental part, p. 158 - 166 (2011/02/23)
An aminopropyltrimethoxysilane functionalized chitosan was found to be an efficient solid base catalyst for the self-aldol condensation of linear aldehydes under solvent-free conditions. The modified catalyst was characterized using physical techniques, elemental analysis, FT-IR, and TGA. The modified chitosan was evaluated for the aldol condensation of C3-C7 linear aldehydes in which the selective formation was obtained for α,β-unsaturated aldehydes. A decreasing trend in the conversion from propanal to heptanal was observed. Propanal and pentanal were subjected for detail investigations to study the effect of parameters like amount of catalyst and aldehyde, and temperature on the conversion and selectivity. Kinetic performance of the modified chitosan investigated for a representative aldehyde, pentanal showed that the rate was increased with the catalyst amount, pentanal and temperature. The catalyst was reused up to six cycles without significant loss in its activity and selectivity.
COMPOUNDS FOR THE CONTROLLED RELEASE OF ACTIVE ALDEHYDES
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Page/Page column 20-21, (2008/06/13)
The present invention relates to the field of perfumery. More particularly, it concerns an aldoxane derivative of Formula (I) capable of protecting an active aldehyde R1CHO, for example a perfumery or flavor aldehyde, from a chemically aggressive medium into which they have to be added, and then of releasing said active aldehyde at the desired moment. The present invention concerns also the use of said compound in perfumery or in the flavor industry as well as the compositions or articles associated with said aldoxanes.
Aldol Reaction and Robinson-Type Annelation Catalyzed by Lanthanoid Triisopropoxides
Okano, Tamon,Satou, Yoshikazu,Tamura, Motoshi,Kiji, Jitsuo
, p. 1879 - 1886 (2007/10/03)
Lanthanoid triisopropoxides are active catalysts for aldol reactions.Aldehydes give the corresponding β-hydroxyaldehydes at low temperatures in good yields, whereas ketones are less reactive, but form condensation products at high temperatures.Exceptionally, γ- or δ-diketones easily undergo condensation to give five- and six-membered unsaturated ketones in high yields.The lanthanoid propoxides, catalyzing the Michael addition of ketones to α,β-unsaturated ketones, which give δ-diketones, are also good catalysts for the Robinson-type annelation.In these reactions, the catalytic activity of the lanthanum propoxide is higher than those of the heavy lanthanoid propoxides, and is almost comparable to that of sodium isopropoxide.Since aluminum triisopropoxide shows poor activity, the lanthanoid propoxides are considerably basic for trivalent metal alkoxides.
