533-49-3Relevant academic research and scientific papers
Selective Reductive Dimerization of CO2into Glycolaldehyde
Zhang, Dan,Jarava-Barrera, Carlos,Bontemps, Sébastien
, p. 4568 - 4575 (2021/05/04)
The selective dimerization of CO2 into glycolaldehyde is achieved in a one-pot two-step process via formaldehyde as a key intermediate. The first step concerns the iron-catalyzed selective reduction of CO2 into formaldehyde via formation and controlled hydrolysis of a bis(boryl)acetal compound. The second step concerns the carbene-catalyzed C-C bond formation to afford glycolaldehyde. Both carbon atoms of glycolaldehyde arise from CO2 as proven by the labeling experiment with 13CO2. This hybrid organometallic/organic catalytic system employs mild conditions (1 atm of CO2, 25 to 80 °C in less than 3 h) and low catalytic loadings (1 and 2.5%, respectively). Glycolaldehyde is obtained in 53% overall yield. The appealing reactivity of glycolaldehyde is exemplified (i) in a dimerization process leading to C4 aldose compounds and (ii) in a tri-component Petasis-Borono-Mannich reaction generating C-N and C-C bonds in one process.
Catalytic Gels for a Prebiotically Relevant Asymmetric Aldol Reaction in Water: From Organocatalyst Design to Hydrogel Discovery and Back Again
Hawkins, Kirsten,Patterson, Anna K.,Clarke, Paul A.,Smith, David K.
supporting information, p. 4379 - 4389 (2020/03/05)
This paper reports an investigation into organocatalytic hydrogels as prebiotically relevant systems. Gels are interesting prebiotic reaction media, combining heterogeneous and homogeneous characteristics with a structurally organized active solid-like catalyst separated from the surrounding environment, yet in intimate contact with the solution phase and readily accessible via liquid-like diffusion. A simple self-assembling glutamine amide derivative 1 was initially found to catalyze a model aldol reaction between cyclohexanone and 4-nitrobenzaldehyde, but it did not maintain its gel structure during reaction. In this study, it was observed that compound 1 could react directly with the benzaldehyde to form a hydrogel in situ based on Schiff base 2 as a low-molecular-weight gelator (LMWG). This new dynamic gel is a rare example of a two-component self-assembled LMWG hydrogel and was fully characterized. It was demonstrated that glutamine amide 1 could select an optimal aldehyde component and preferentially assemble from mixtures. In the hunt for an organocatalyst, reductive conditions were applied to the Schiff base to yield secondary amine 3, which is also a highly effective hydrogelator at very low loadings with a high degree of nanoscale order. Most importantly, the hydrogel based on 3 catalyzed the prebiotically relevant aldol dimerization of glycolaldehyde to give threose and erythrose. In buffered conditions, this reaction gave excellent conversions, good diastereoselectivity, and some enantioselectivity. Catalysis using the hydrogel of 3 was much better than that using non-assembled 3 - demonstrating a clear benefit of self-assembly. The results suggest that hydrogels offer a potential strategy by which prebiotic reactions can be promoted using simple, prebiotically plausible LMWGs that can selectively self-organize from complex mixtures. Such processes may have been of prebiotic importance.
Kinetics and mechanism of quinolinium dichromate mediated oxidation of sugar alcohols in Bronsted acid media
Kodali, Satish Babu,Jakku, Narendar Reddy,Kamatala, Chinna Rajanna,Yerraguntla, Rajeshwar Rao
, p. 167 - 177 (2019/12/27)
Bronsted acid catalyzed oxidation of certain sugar alcohols (polyols) has been studied by quinolinium dichromate (QDC) using aqueous sulfuric, perchloric, and hydrochloric acids at different temperatures. At constant acidity, reaction kinetics revealed the second-order kinetics with a first order in [Alcohol] and [QDC]. Zucker-Hammett, Bunnett, and Bunnett-Olsen criteria were used to analyze acid-dependent rate accelerations. Bunnett-Olsen plots of (log k + Hν) versus (Hν + log [H+]), and (log k) versus (Hν + log [H+]) afforded slope values (? and ?*, respectively)?>?0.47, suggesting that a water molecule acts as a prton transfer agent in the slow step of the mechanism in the oxidation of alcohols by QDC in the presence of aqueous sulfuric, perchloric, and hydrochloric acids.
Convergent in situ Generation of Both Transketolase Substrates via Transaminase and Aldolase Reactions for Sequential One-Pot, Three-Step Cascade Synthesis of Ketoses
Lorillière, Marion,Guérard-Hélaine, Christine,Gefflaut, Thierry,Fessner, Wolf-Dieter,Clapés, Pere,Charmantray, Franck,Hecquet, Laurence
, p. 812 - 817 (2019/12/27)
We describe an efficient three-enzyme, sequential one-pot cascade reaction where both transketolase substrates are generated in situ in a convergent fashion. The nucleophilic donor substrate hydroxypyruvate was obtained from l-serine and pyruvate by a transaminase-catalyzed reaction. In parallel, three different (2S)-α-hydroxylated aldehydes, l-glyceraldehyde, d-threose, and l-erythrose, were generated as electrophilic acceptors from simple achiral compounds glycolaldehyde and formaldehyde by d-fructose-6-phosphate aldolase catalysis. The compatibility of the three enzymes was studied in terms of temperature, enzyme ratio and substrate concentration. The efficiency of the process relied on the irreversibility of the transketolase reaction, driving a shift of the reversible transamination reaction and securing the complete conversion of all substrates. Three valuable (3S,4S)-ketoses, l-ribulose, d-tagatose, and l-psicose were obtained in good yields with high diastereoselectivity.
Shape-selective Valorization of Biomass-derived Glycolaldehyde using Tin-containing Zeolites
Tolborg, S?ren,Meier, Sebastian,Saravanamurugan, Shunmugavel,Fristrup, Peter,Taarning, Esben,Sádaba, Irantzu
, p. 3054 - 3061 (2016/11/17)
A highly selective self-condensation of glycolaldehyde to different C4 molecules has been achieved using Lewis acidic stannosilicate catalysts in water at moderate temperatures (40–100 °C). The medium-sized zeolite pores (10-membered ring framework) in Sn-MFI facilitate the formation of tetrose sugars while hindering consecutive aldol reactions leading to hexose sugars. High yields of tetrose sugars (74 %) with minor amounts of vinyl glycolic acid (VGA), an α-hydroxyacid, are obtained using Sn-MFI with selectivities towards C4 products reaching 97 %. Tin catalysts having large pores or no pore structure (Sn-Beta, Sn-MCM-41, Sn-SBA-15, tin chloride) led to lower selectivities for C4 sugars due to formation of hexose sugars. In the case of Sn-Beta, VGA is the main product (30 %), illustrating differences in selectivity of the Sn sites in the different frameworks. Under optimized conditions, GA can undergo further conversion, leading to yields of up to 44 % of VGA using Sn-MFI in water. The use of Sn-MFI offers multiple possibilities for valorization of biomass-derived GA in water under mild conditions selectively producing C4 molecules.
Catalytic effect of aluminium chloride on the example of the conversion of sugar model compounds
Schwiderski, Martin,Kruse, Andrea
, p. 64 - 70 (2015/04/14)
Abstract In this work, the catalytic effect of the Bronsted acid hydrochloric acid, the Bronsted base sodium hydroxide and the Lewis acid AlCl3 on the conversion of biomass derived carbohydrates is investigated. On the example of the glycolaldehyde conversion, it is shown that the Lewis acid catalyses the ketol-endiol-tautomerism, the dehydration, the retro-aldol-reaction and the benzilic-acid-rearrangement. The main products are C4- and C6-carbohydrates as well as their secondary products 2-hydroxybut-3-enoic acid 1 and several furans. Under the same reaction conditions hydrochloric acid catalyzes mainly the dehydration and sodium hydroxide the tautomerism and subsequent aldolization.
Tertiary Amine Promoted Asymmetric Aldol Reaction of Aldehydes
Gut, Bartosz,Mlynarski, Jacek
, p. 5075 - 5078 (2015/08/18)
The direct asymmetric self-aldol reactions of various α-oxyaldehydes catalyzed by tertiary amines have been demonstrated. By using 10 mol-% of quinine catalyst, dimerization products have been prepared in high yields, with good anti-diastereocontrol, and up to 80% ee. The presented enolate-mediated synthesis of protected tetrose sugars has never been accomplished before by chiral tertiary amine organocatalysts.
Asymmetric organocatalytic formation of protected and unprotected tetroses under potentially prebiotic conditions
Burroughs, Laurence,Clarke, Paul A.,Forintos, Henrietta,Gilks, James A. R.,Hayes, Christopher J.,Vale, Matthew E.,Wade, William,Zbytniewski, Myriam
experimental part, p. 1565 - 1570 (2012/04/05)
Esters of proteinogenic amino acids efficiently catalyse the formation of erythrose and threose under potentially prebiotic conditions in the highest yields and enantioselectivities yet reported. Remarkably while esters of (l)-proline yield (l)-tetroses, esters of (l)-leucine, (l)-alanine and (l)-valine generate (d)-tetroses, offering the potential to account for the link between natural (l)-amino acids and natural (d)-sugars. The effect of pH and NaCl on the yields and enantioselectivities was also investigated and was shown to be significant, with the optimal enantioselectivities occurring at pH 7.
Kinetics and mechanism of oxidation of L-sorbose by tetraethylammonium chlorochromate in aqueous acetic acid
Tomar, Ashish,Kumar, Arun
, p. 1162 - 1165 (2008/09/21)
The kinetics of oxidation of L-sorbose by tetraethylammonium chlorochromate in aqueous acetic acid 50% (v/v) medium has been investigated. The reaction has been found to be first order with respect to each of the [oxidant] and [substrate] under pseudo-first order conditions. The reaction is catalyzed by acid and a medium of low dielectric constant favors the oxidation reaction. The ionic strength variation does not influence the reaction rate. A 1:1 stoichiometry is observed in the oxidation and the reaction rate is not retarded by radical trapping agent, acrylonitrile. The erythrose and glycolic acid have been identified as main products of the oxidation. The effect of temperature is studied and activation parameters are determined. On the basis of kinetic results, a hydride ion transfer mechanism is proposed.
Methods for the electrolytic production of erythrose or erythritol
-
Page/Page column 8-9, (2008/06/13)
Methods for the production of erythrose and/or erythritol are provided herein. Preferably, the methods include the step of electrolytic decarboxylation of a ribonic acid or arabinonic acid reactant to produce erythrose. Optionally, the reactant can be obtained from a suitable hexose sugar, such as allose, altrose, glucose, fructose or mannose. The erythrose product can be hydrogenated to produce erythritol.
