15909-76-9Relevant academic research and scientific papers
Synthesis of Alkyl (+/-)-2,3-Di-O-acylglycerates and Attempts Directed to their Conversion into Alkyl (R)-2,3-Di-O-acylglycerates by Enzyme-catalyzed Enantioselective Deacylation Reactions
Schick, H.,Schroetter, E.,Szymanowski, M.,Knoll, A.
, p. 628 - 632 (1993)
By screening several lipases and proteases as catalysts for an enantioselective partial deacylation of methyl (+/-)-2,3-di-O-acylglycerates, it was found that methyl (R)-2,3-di-butanoylglycerate can be obtained with an enantiomeric excess of >96percent and a yield of 20percent related to the racemic starting material.This was prepared from methyl acrylate through dihydroxylation with potassium permanganate at -30 deg C and a subsequent bisacylation.
Characterization of QmnD3/QmnD4 for double bond formation in quartromicin biosynthesis
Wu, Long-Fei,He, Hai-Yan,Pan, Hai-Xue,Han, Li,Wang, Renxiao,Tang, Gong-Li
, p. 1578 - 1581 (2014)
In this work, two enzymes responsible for the biogenesis of possible [4 + 2] reaction precursors in the quartromicin biosynthetic pathway were characterized: acetylation of 1 to yield 2 was catalyzed by QmnD3, and subsequent acetic acid elimination of 2 to form double bond product 3 was catalyzed by QmnD4. Site-directed mutagenesis assay of QmnD3 and QmnD4 was investigated, and a general base-catalyzed mechanism for QmnD4 is proposed.
Base-free conversion of glycerol to methyl lactate using a multifunctional catalytic system consisting of Au-Pd nanoparticles on carbon nanotubes and Sn-MCM-41-XS
Tang, Zhenchen,Boer, Dina G.,Syariati, Ali,Enache, Mihaela,Rudolf, Petra,Heeres, Hero J.,Pescarmona, Paolo P.
, p. 4115 - 4126 (2019)
Multifunctional catalytic systems consisting of physical mixtures of (i) bimetallic Au-Pd nanoparticles (average size of 3-5 nm) supported on functionalised carbon nanotubes (CNTs) and (ii) Sn-MCM-41 nanoparticles (50-120 nm), were synthesised and investigated for the base-free, selective conversion of glycerol to methyl lactate in a batch reactor. The catalysts were characterised by means of transmission electron microscopy, N2-physisorption, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and by Boehm titration. The catalyst based on bimetallic AuPd/CNTs showed much higher activity than the monometallic Au or Pd counterparts, thus indicating synergetic effects. Functionalisation of the CNTs by oxidative treatments had a positive effect on catalyst performance, which was correlated to the observed increase in surface acidity and hydrophilicity. The highest yield of methyl lactate achieved in this work was 85% at 96% glycerol conversion (140 °C, 10 h at 30 bar air), which is the highest yield ever reported in the literature so far. Insights in the reaction pathway were obtained by monitoring the conversion-time profiles for intermediates and their possible role as inhibitors. Batch recycling experiments demonstrated the excellent reusability of the catalyst.
Catalytic Conversion of Diethyl Tartrate into Pyruvate over Silica-Supported Potassium Disulfate
Sugiyama, Shigeru,Fukunaga, Sadao,Kawashiro, Katsuhiro,Hayashi, Hiromu
, p. 2083 - 2085 (1992)
Potassium hydrogensulfate (KHSO4), which melts at a lower temperature of 197 deg, was adapted for vapor-phase fixed-bed flow operations as a silica-supported potassium disulfate (K2S2O7/SiO2) to afford 60percent ethyl pyruvate continuously from the tartrate at 300 deg C.The catalyst was effective for the intramolecular dehydration of glycol moieties, much less active for hydrolysis of esters, and capable of converting enol- to keto-form for the intermediate oxalacetate in favor of pyruvate.A TGA analysis revealed that KHSO4 was converted to K2S2O7 at 300 deg C, this was in consistent with the XRD analysis.
Aromatic Donor-Acceptor Interaction-Based Co(III)-salen Self-Assemblies and Their Applications in Asymmetric Ring Opening of Epoxides
Liang, Jian,Soucie, Luke N.,Blechschmidt, Daniel R.,Yoder, Aaron,Gustafson, Addie,Liu, Yu
supporting information, p. 513 - 518 (2019/01/14)
Aromatic donor-acceptor interaction as the driving force to assemble cooperative catalysts is described. Pyrene/naphthalenediimide functionalized Co(III)-salen complexes self-assembled into bimetallic catalysts through aromatic donor-acceptor interactions and showed high catalytic activity and selectivity in the asymmetric ring opening of various epoxides. Control experiments, nuclear magnetic resonance (NMR) spectroscopy titrations, mass spectrometry measurement, and X-ray crystal structure analysis confirmed that the catalysts assembled based on the aromatic donor-acceptor interaction, which can be a valuable noncovalent interaction in supramolecular catalyst development.
An Esterase-like Lyase Catalyzes Acetate Elimination in Spirotetronate/Spirotetramate Biosynthesis
Lees, Nicholas R.,Han, Li-Chen,Byrne, Matthew J.,Davies, Jonathan A.,Parnell, Alice E.,Moreland, Pollyanna E. J.,Stach, James E. M.,van der Kamp, Marc W.,Willis, Christine L.,Race, Paul R.
supporting information, p. 2305 - 2309 (2019/01/29)
Spirotetronate and spirotetramate natural products include a multitude of compounds with potent antimicrobial and antitumor activities. Their biosynthesis incorporates many unusual biocatalytic steps, including regio- and stereo-specific modifications, cyclizations promoted by Diels–Alderases, and acetylation-elimination reactions. Here we focus on the acetate elimination catalyzed by AbyA5, implicated in the formation of the key Diels–Alder substrate to give the spirocyclic system of the antibiotic abyssomicin C. Using synthetic substrate analogues, it is shown that AbyA5 catalyzes stereospecific acetate elimination, establishing the (R)-tetronate acetate as a biosynthetic intermediate. The X-ray crystal structure of AbyA5, the first of an acetate-eliminating enzyme, reveals a deviant acetyl esterase fold. Molecular dynamics simulations and enzyme assays show the use of a His-Ser dyad to catalyze either elimination or hydrolysis, via disparate mechanisms, under substrate control.
Concise Asymmetric Synthesis of Kweichowenol A
Konrad, David B.,Kicin, Bilal,Trauner, Dirk
supporting information, p. 383 - 386 (2019/02/26)
An asymmetric 11-step synthesis of the polyoxygenated cyclohexene natural product kweichowenol A from the traditional Chinese medicinal herb Uvaria kweichowesis is reported. The oxygenation pattern was installed on a linear precursor by exploiting the acyclic stereocontrol of the Kiyooka aldol reaction, as well as Cram chelate-controlled Grignard reactions. Ring-closing metathesis and a selective benzoylation then gave the natural product.
Synthesis of Phosphatidylserine and Its Stereoisomers: Their Role in Activation of Blood Coagulation
Mallik, Suman,Prasad, Ramesh,Bhattacharya, Anindita,Sen, Prosenjit
supporting information, p. 434 - 439 (2018/05/23)
Natural phosphatidylserine (PS), which contains two chiral centers, enhances blood coagulation. However, the process by which PS enhanced blood coagulation is not completely understood. An efficient and flexible synthetic route has been developed to synthesize all of the possible stereoisomers of PS. In this study, we examined the role of PS chiral centers in modulating the activity of the tissue factor (TF)-factor VIIa coagulation initiation complex. Full length TF was relipidated with phosphatidylcholine, and the synthesized PS isomers were individually used to estimate the procoagulant activity of the TF-FVIIa complex via a FXa generation assay. The results revealed that the initiation complex activity was stereoselective and had increased sensitivity to the configuration of the PS glycerol backbone due to optimal protein-lipid interactions.
Direct conversion of C6 sugars to methyl glycerate and glycolate in methanol
Feng, Lei,Li, Gang,Yan, Yueer,Hou, Wenrong,Zhang, Yahong,Tang, Yi
, p. 30163 - 30170 (2018/09/11)
The present work deals with the one-pot conversion of C6 sugars to methyl glycerate and glycolate via a cascade of retro-aldol condensation and oxidation processes catalyzed by using MoO3 as the Lewis acid catalyst and Au/TiO2 as the oxidation catalyst in methanol. Methyl glycerate (MGLY) is the product of C6 ketose (fructose), while methyl glycolate (MG) is produced from C6 aldose (mannose, glucose). It is found that a good one-pot match between two reactive processes is the key to the production of MGLY and MG with high yield (27.6% MGLY and 39.2% MG). A separated retro-aldol condensation and oxidation process greatly decreases their yields, and even no MGLY can be obtained in this separated process. We attribute this to high instability of glyceraldehyde/glycolaldehyde and their different reaction pathways which mainly depend on whether acetalization of retro-aldol products (glyceraldehyde and glycolaldehyde) occurs with methanol or not. This result opens a new prospect on the accumulation of C3 products other than lactate from biomass-derived carbohydrates.
Dihydroxylation of Olefins with Potassium Permanganate Catalyzed by Imidazolium Salt
Khan, Imran,Luo, Zhi-Bin,Valeru, Anil,Xu, Yin,Liu, Bin,Sangepu, Bhavanarushi,Xie, Ji-Min
, p. 1815 - 1819 (2018/02/19)
The development of an efficient and cost-effective cis -dihydroxylation reaction of acrylate derivatives was achieved. The reaction proceeded in acetone with an imidazolium salt as catalyst to furnish the dihydroxylation of olefins at 0-5 °C using KMnO 4 as the oxidant. This efficient and non-aqueous protocol was highly suitable for the large-scale preparation of cis -dihydroxylated compounds from the corresponding acrylate derivatives in high yields without overoxidation.
