[reaction: see text] A new poly(ethylene glycol)-supported porphyrin has been prepared and its ability as a promoter in photooxidation reactions has been studied. The PEG-supported catalyst exhibits high activity, comparable to that of a nonanchored sensitizer, and it is easily removable by filtration from the reaction mixture. The polymer-bound porphyrin has been recycled up to six times with no loss of chemical and stereochemical efficiency.
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http://dx.doi.org/10.1021/ol0267230 | DOI Listing |
J Org Chem
September 2016
Department of Chemistry, University of Calgary , 2500 University Drive N.W., Calgary, Alberta T2N 1N4, Canada.
Diaryl selenides containing o-hydroxymethylene substituents function as peroxide-destroying mimetics of the antioxidant selenoenzyme glutathione peroxidase (GPx), via oxidation to the corresponding spirodioxyselenuranes with hydrogen peroxide and subsequent reduction back to the original selenides with glutathione. Parent selenides with 3-hydroxypropyl or 2,3-dihydroxypropyl groups produced the novel compounds 10 and 11, respectively, with greatly improved aqueous solubility and catalytic activity. The phenolic derivative 28 displayed similarly ameliorated properties and also modest radical-inhibiting antioxidant activity, as evidenced by an assay based on phenolic hydrogen atom transfer to the stable free radical DPPH.
View Article and Find Full Text PDFAdv Mater
November 2014
Materials Science and Engineering Program & Texas Materials Institute, The University of Texas at Austin, Austin, TX, 78712, USA.
A composite separator with a thin-film polysulfide trap is developed for lithium-sulfur batteries. A polyethylene glycol-supported microporous carbon coating (MPC/PEG coating) on a Celgard separator suppresses polysulfide diffusion through its physical and chemical polysulfide-trapping capabilities. The MPC/PEG-coated separator thus facilitates the use of pure sulfur cathodes that generally suffer from poor cyclability and low electrochemical utilization.
View Article and Find Full Text PDFChemistry
May 2011
Dipartimento di Chimica Organica e Industriale, Università degli Studi di Milano, Via Venezian 21, 20133 Milano, Italy.
An efficient total synthesis of the natural alkaloid (+)-dumetorine by using flow technology is described. The process entailed five separate steps starting from the enantiopure (S)-2-(piperidin-2-yl)ethanol 4 with 29% overall yield. Most of the reactions were carried out by exploiting solvent superheating and by using packed columns of immobilized reagents or scavengers to minimize handling.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
August 2010
Department of Chemical Sciences, Tezpur University, Napaam, Assam, India.
The present work reports the integration of polymer matrix-supported nanomaterial and enzyme biotechnology for development of industrially feasible biocatalysts. Aqueous leaf extract of Mesua ferrea L. was used to prepare silver nanoparticles distributed within a narrow size range (1-12 nm).
View Article and Find Full Text PDFNanotechnology
June 2009
Advanced Polymer and Nanomaterial Laboratory, Department of Chemical Sciences, Tezpur University, Tezpur-784028, Assam, India.
Nanotechnology holds the prospect for avant-garde changes to improve the performance of materials in various sectors. The domain of enzyme biotechnology is no exception. Immobilization of industrially important enzymes onto nanomaterials, with improved performance, would pave the way to myriad application-based commercialization.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!