Methyl α-D-glucopyranoside as a model acceptor was acylated by several phenolic and non-phenolic vinyl esters using immobilised Lipolase. Donor specificity and regioselectivity of reaction were investigated. Conversion and rate of acylation by structurally varied donors indicates that the synthetic reactivity of Lipolase corresponds to the hydrolytic activity of feruloyl esterase type A. Lipolase exhibited remarkable regioselectivity for primary position of methyl α-D-glucopyranoside. The acylation occurred exclusively at 6-O primary position when vinyl esters of phenolic acids (hydroxybenzoates, hydroxyphenylalkanoates and hydroxycinnamates) served as acyl donors (5-77%). In addition to the major 6-O-acyl products (52-79%), 2,6-di-O-acylated derivatives were isolated from reaction mixtures (2-13%) when non-phenolic donors were used (vinyl esters of fully methoxylated derivatives of phenolic acids, along with vinyl benzoates, cinnamates or some heterocyclic analogues).
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http://dx.doi.org/10.1016/j.bmcl.2013.07.051 | DOI Listing |
Molecules
December 2024
Syensqo, Centre de Recherche et Innovation Aubervilliers, 52 Rue de la Haie Coq, 93308 Aubervilliers Cedex, France.
Rhodixan A1 is the trade name for -ethyl -(1-methoxycarbonylethyl)dithiocarbonate, a RAFT/MADIX agent used by Syensqo to produce block copolymer additives for aqueous formulations on an industrial scale. Chain transfer coefficients to Rhodixan A1 determined for 25 different styrenic, acrylate, and acrylamide monomers were relatively low (0.6 < C < 3.
View Article and Find Full Text PDFHeliyon
December 2024
Department of Chemical Engineering, Madonna University, Akpugo Campus, 402105, Akpugo, Enugu State, Nigeria.
The present study examined the corrosion protection of aluminium in 1M HCl by deploying expired danacid, with techniques such as gravimetric, electrochemical, and density functional theory (DFT). Inhibitor characterization was executed with Fourier transform infrared (FTIR) spectroscopy and gas chromatography mass spectrometry (GC-MS), which was supplemented by optimization of parameters with response surface methodology. The results of gravimetric study indicates that the inhibition efficiency (IE) rose with rise in danacid concentration and reduced with rise in temperature.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Laboratory of Catalysis and Organic Synthesis, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland.
The azidofunctionalization of alkenes under mild conditions using commercially available starting materials and easily accessible reagents is reported based on a radical-polar crossover strategy. A broad range of alkenes, including vinyl arenes, enamides, enol ethers, vinyl sulfides, and dehydroamino esters, were regioselectively functionalized with an azide and nucleophiles such as azoles, carboxylic acids, alcohols, phosphoric acids, oximes, and phenols. The method led to a more efficient synthesis of 1,2-azidofunctionalized pharmaceutical intermediates when compared to previous approaches, resulting in both reduction of step count and increase in overall yield.
View Article and Find Full Text PDFACS Biomater Sci Eng
January 2025
Henan International Joint Laboratory of Medicinal Plants Utilization, College of Chemistry and Molecular Sciences, Henan Key Laboratory of Natural Medicine Innovation and Transformation, State Key Laboratory of Antiviral Drugs, Henan University, Kaifeng 475004, China.
Int J Biol Macromol
December 2024
Graduate Program in Chemistry, Federal University of Alfenas, Alfenas, MG 37130-001, Brazil; Institute of Chemistry, Federal University of Alfenas, Alfenas, MG 37130-001, Brazil. Electronic address:
The objective of this study was to produce new and renewable bio-based plasticizers from used soybean cooking oil (USCO). First, USCO was completely converted into free fatty acids (FFAs) using lipase from Candida rugosa. Next, these FFAs were enzymatically esterified with benzyl alcohol in solvent-free systems.
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