1,721,070 research outputs found
Flustrates: an attractive challenge for organic chemists
No full textAs witnessed by the large number of articles, reviews and books
concerning fluoro-organic chemistry that have been published
recently, the interest of scientific community toward this particular
research field of synthetic organic chemistry has gone up. The
present article does not cover a specific topic but rather intends to
analyse some peculiar features typical of fluorine-containing
compounds, in order to catch laymen attention toward the
fascinating and still mysterious world of organofluorine chemistry
An Efficient Support for the Immobilisation of Enzymes: Tyrosinase on Carbon Nanotubes for Biocatalytic ends
No full textInsights on the mechanistic features of catalytic oxidations of simple and conjugated olefins promoted by VO(acac)2/H2O2 system
No full textIMMOBILIZATTIION OF MTO. Part 2: A way to enhance oxidative catalysts versatility
No full textFrom an academic and industrial point of view, the interest in the development of environment
friendly heterogeneous catalytic processes gained recently an ever increasing importance.
The results obtained in the last five years, in the selective oxidative functionalization of many
different organic substrates by means of the novel polymer supported methyltrioxorhenium/H2O2
catalytic systems, are presented
Toward a novel approach for oxidative desulfurization (ODS) of diesel fuel: An efficient oxidation of thiophene derivatives with homogeneous and heterogeneous MTO/H2O2 systems
No full textOrganosulfur compounds in fuel oils are known to have a negative impact onto the environment because of SOx emissions from their combustion exhausts. As a consequence, removal of sulfur is becoming a worldwide challenge, also due to more and more stringent regulations. In this communication, our recent results obtained in the oxidation of benzothiophene (BTs) and dibenzothiophene (DBTs) derivatives contained in either a model fuel (MF) or an authentic diesel fuel (ADF), with homogeneous and heterogeneous rhenium catalysts and H2O2, will be showed. This catalytic method has been studied with the aim of designing an alternative environmentally benign oxidative desulfurization process (ODS), for oil industry. The quantitative conversion of both BTs and DBTs derivatives to the corresponding sulfones was obtained in several of the cases investigated. Excellent results in terms of both conversion of substrates and yields of sulfones were also obtained during oxidation of MF and ADF. Heterogeneous rhenium catalysts were stable systems to be used for several runs without any appreciable reduction of reactivity and selectivity
Advances in the Synthesis of Bioactive Unnatural Amino Acids and Peptides
No full textThe key role of proteins and amino acids in the structure and function of living matter has stimulated extensive
studies. Modified amino acids with enhanced biological activity, proteolitic stability and bioavailability are of increasing
interest in protein design and engineering as drug candidates. In the last few years, several efforts have been devoted to
the synthesis of amino acids having unusual side chains and unnatural chirality, commonly referred to as
“nonproteinogenic” or “unnatural” amino acids, even though some of them can be isolated from natural sources. In this
review we describe recent advances in the amino acid side-chain transformations and backbone modifications by
oxidative and fluorination procedures
Stereoselective Synthesis of Optically Pure gamma-Fluoro-beta-Enaminosulfoxides and Reduction to gamma-Fluoro-beta-Aminosulfoxides
No full textThe aza-Wittig reaction of phospha&5-azenes with optically pure y-fluorosubstituted I~-
ketosulfoxides leads to the corresponding 13-enaminosulfoxides, which were easily isolated in
diastereomerically pure form. The stercoselective reduction of the enamine 3cb afforded the optically
pure [~-sulphinyl-amine5 cb in high overall yield
Stereoselective cyclisations of fluoroalkyl radicals involving sulfur-substituted chiral intermediates
No full textEnantiomerically pure fluorinated substrates of type 1-5 undergo stereoselective radical cyclisation affording variously substituted tetrahydrofurans, cyclopentanes, and cyclohexanes. The control exerted on the formation of the new stereocentres by those already present is discussed. Elaborations to chlorine-and sulfur-free derivatives possessing up to five stereocentres are presented
First method for the preparation of strongly electrophilic chiral sulfinimines, and applications in asymmetric synthesis
No full textA new and preparatively useful method for the synthesis of non racemic alpha-trifluoromethyl alpha-amino acids is presented, using chiral sulfinimines of trifluoropyruvate as key-building blocks
Immobilization of MTO. Part 1: a way to enhance oxidative catalysts versatility
No full textFrom an academic and industrial point of view, the interest in the development of environment
friendly heterogeneous catalytic processes gained recently an ever increasing importance.
The results obtained in the last five years, in the selective oxidative functionalization of many
different organic substrates by means of the novel polymer supported methyltrioxorhenium/H2O2
catalytic systems, are presented
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