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Micronutrients
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
Unlike coenzymes, true cofactors are inorganic compounds. Usually, cofactors are metal ions. Thousands of enzymatic reactions require metal ion cofactors in functions ranging from Lewis acid catalysis to redox catalysis and electron transfer (91).
Drug Design, Synthesis, and Development
Published in Nathan Keighley, Miraculous Medicines and the Chemistry of Drug Design, 2020
Benzene commonly reacts with electrophiles via electrophilic substitution reactions. For example, nitration, sulfonation, and halogenation reactions, which all require a Lewis acid catalyst; an acceptor of electrons, are useful ways of introducing new functional groups to aromatic rings. Another useful example for synthesis would be the Friedel-Craft reactions (acylation and alkylation) because these form new carbon-carbon bonds, useful for combining molecular fragments.
Chemistries of Chemical Warfare Agents
Published in Brian J. Lukey, James A. Romano, Salem Harry, Chemical Warfare Agents, 2019
Terry J. Henderson, Ilona Petrikovics, Petr Kikilo, Andrew L. Ternay Jr., Harry Salem
In general, aromatic hydrocarbons are less nucleophilic than are simple alkenes. The chlorination of less nucleophilic aromatics, for example, C6H6, requires the use of a Lewis acid catalyst (anhydrous aluminum chloride, for example) and either excess of the liquid aromatic compound or an inert solvent. The product, C6H5Cl, results from a net substitution process. The chlorination (ortho or para) of activated aromatics such as anisole, C6H5OCH3, may not require a catalyst.
Potential anti-neuroinflammatory NF-кB inhibitors based on 3,4-dihydronaphthalen-1(2H)-one derivatives
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2020
Yue Sun, Yan-Qiu Zhou, Yin-Kai Liu, Hong-Qin Zhang, Gui-Ge Hou, Qing-Guo Meng, Yun Hou
In this study, the synthetic routes to 3,4-dihydronaphthalen-1(2H)-one derivatives are shown in Schemes 1 and 2. A key intermediate, 7-methoxy-3,4-dihydronaphthalen-1(2H)-one (5), was prepared with an overall yield of 48% using the three steps based on the method described in the literature21,24. First, anisole (1) and succinic anhydride (2) were combined to generate 4–(4-methoxyphenyl)-4-oxobutanoic acid (3) by Lewis acid catalysis (anhydrous AlCl3) with a 92% yield. Secondly, after Wolff-Kishner-Huang-Minlon reduction of 3, 4-phenoxybutanoic acid 4 was generated with an 86% yield. Then, the key intermediate 5 was prepared for cyclisation in the presence of PPA with a lower yield of 65%. Lastly, 5 and several aromatic aldehydes were subjected to Claisen-Schmidt condensation to yield a series of new 3,4-dihydronaphthalen-1(2H)-one derivatives (6a-n). The yields of 6a-n reached approximately 80–91%. During this last step, dry HCl, aqueous NaOH, or other bases can be chosen as the catalyst27. Considering its environmental friendliness and availability to laboratories, a 20% NaOH solution was selected as the catalyst (Scheme 1).
Synthesis and structure-activity relationships of cerebroside analogues as substrates of cerebroside sulphotransferase and discovery of a competitive inhibitor
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2020
Wenjin Li, Joren Guillaume, Younis Baqi, Isabell Wachsmann, Volkmar Gieselmann, Serge Van Calenbergh, Christa E. Müller
The required azidoglycoside 23 was obtained through Lewis acid-catalysed glycosidation reaction as previously reported28. Staudinger reduction and subsequent EDC-mediated acylation with the appropriate fatty acid furnished 24 and 25. Final catalytic hydrogenolysis yielded α-galactosylceramides 12 and 17. To avoid saturation of the cis-double bond of 15-tetracosanoic acid, the amino group generated after Staudinger reduction was Boc-protected prior to the removal of the benzyl groups to afford intermediate 27. Subsequent removal of the Boc moiety with HCl in acetic acid gave the corresponding psychosine derivative, which was subjected to Schotten–Baumann acylation with 15-tetracosanoyl chloride to afford glycolipid 22.