Special Issue "Fluorine Chemistry"

Guest Editor
Prof. Dr. Bela Torok
Department of Chemistry, University of Massachusetts Boston, 100 Morrissey Blvd. Boston, MA 02125, USA
Website: http://alpha.chem.umb.edu/faculty/torok/Torok%20Website/index.html
E-Mail:
Interests: organofluorine chemistry; heterogeneous catalysis; heterocyclic chemistry; asymmetric synthesis; catalytic hydrogenation; microwave-assisted organic synthesis; medicinal chemistry

Dear Colleagues,

Since the discovery of the beneficial effects of fluorine incorporation into organic molecules the synthesis and application of organofluorine compounds underwent an explosion like development. The major driving force of such developments was the pharmaceutical industry; however, organofluorine compounds are widely applied in many other applications from plastics, to refrigeration.
In this special issue, our goal is to provide an overview of this exciting research field, as broad as possible, highlighting recent developments in the design, synthesis and application of fluorine compounds.
It is our hope that this Special Issue on Fluorine Chemistry will become an attractive forum to scientists who either work on the synthesis of fluorinated compounds, or apply these compounds for different purposes. Thus this issue will be an excellent medium to present synthesis, structural analysis, pharmacological and therapeutic potential and other applications of fluorine compounds. I strongly encourage authors to submit papers for this Special Issue on Fluorine Chemistry, within the scope of Molecules. I hope that the topics covered will reflect the vast array of synthetic and application possibilities and generate potential future developments in this and related fields.

Dr. Bela Torok
Guest Editor

Submission

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed Open Access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1400 CHF (Swiss Francs).

• fluorine
• synthesis
• medicinal chemistry
• pharmacology
• polymer
• imaging
• probe molecules
• environmental
• structural analysis
• nanoparticles

Type of Paper: Review
Title: Recent Advances in the Application of Selectfluor^TM F-TEDA-BF₄ as a Versatile Mediator or Catalyst in Organic Synthesis
Author: Stojan Stavber
Affiliation: “Jožef Stefan” Institute, Jamova 39, 1000 Ljubljana, Slovenia; E-Mail: stojan.stavber@ijs.si
Abstract: Selectfluor^TM F-TEDA-BF₄ (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate)) is not only one of the most efficient and popular reagent for electrophilic fluorination but as a strong oxidant also a convenient mediator or catalyst of several “fluorine free” functionalizations of organic compounds. Its application as a mediator in gold-catalyzed C-C oxidative coupling reactions, catalyst in a formation of various heterocyclic rings, reagent or catalyst for various functionalization of electron rich organic compounds (iodination, bromination, chlorination, nitration, thiocyanation, sulfenylation, alkylation, alkoxylation), catalyst for one-pot-multi-component coupling reactions, catalyst for regioselective ring opening of epoxides, deprotection reagent for various protecting groups, and mediator for stereoselective rearrangement processes of bicyclic compounds is reviewed and discussed.

Type of Paper: Article
Title: Peculiar 1H NMR Chemical Shift in BINAP Bearing C6F5: Influence of Ring Current Effect of Perfluoroaromatic Group
Authors: Toshinobu Korenaga, Fuminao Kobayashi, Kenji Nomura, Kazunori Horitani and Takashi Sakai
Affiliation: Division of Chemistry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University;
E-Mail: korenaga@cc.okayama-u.ac.jp (T.K.)
Abstract: Now, we are interested in highly electron-poor chiral diphosphine ligand for transition-metal catalyzed asymmetric reaction. As part of this study, we tried to synthesize BINAP ligand bearing pentafluorophenyl groups. Although the novel diphosphine was obtained in only low yield, the peculiar chemical shift was observed in 1H NMR as compared to that of original BINAP. Therefore, the difference was considered with theoretical calculations of chemical shift by DFT calculations.

Type of Paper: Article
Title: Perfluoroallylation of Oxygen Nucleophyles
Authors: Vito Tortelli, Ivan Wlassics, Serena Carella and Giuseppe Marchionni
Affliation: Monomers&Intermediates Chemistry, Solvay Solexis, Viale Lombardia 20-20221 Bollate (MI) Italy; E-Mail: Vito.Tortelli@solvay.com (V.T.); Giuseppe.Marchionni@solvay.com (G.M.)
Abstract: The reaction of several alcohols with perFluoroAllyl FluoroSulphate CF2=CFCF2OSO2F (FAFS) has been studied. Both aliphatic and aromatic alcohols have been used: the addition-elimination product, ie a perfluoroallyl alcohoxy ether, was the main product, but the substitution to the sulphur electrophilic center, with fluoride ion acting as the leaving group, competes yielding a perfluoroallilic sulphate ester. The reasons of this different reactivity will be explained both in terms of structure of the alcoholate and cation used. The reaction can be base catalyzed but often proceeds without the base: the pKa of the alcohol is the critical parameter in this sense. We have studied the addition to FAFS of the peroxy anion as well, generated from the system base/hydrogen peroxide: the selectivity to different peroxidic products and the kinetic investigation of the reaction will be detailed.

Type of Paper: Review
Title: Application of radioactive fluorine in molecular imaging of biological/biochemical processes by positron emission tomography (PET)
Authors: Nashaat Turkman and Mian Alauddin
Affiliation: Department of Experimental Diagnostic Imaging, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA; E-Mail: alauddin@mdanderson.org
Abstract: Cady and colleagues published the first series of papers in 1948, on the hypofluorite compounds, including the oxygen-fluorine group, -OF. Trifluoromethyl hypofluorite, CF3OF, was prepared by catalytic fluorination of methanol (CH3OH). Cady achieved the first synthesis and characterization of xenon hexafluoride, which is of particular interest to chemists, because as one of the noble gases, xenon shuns other elements, refusing to take part in any kind of chemical bond.
Organofluorine compounds are organic compounds that contain carbon and fluorine bonded in the polarized and remarkably strong carbon–fluorine bond. Organofluorine compounds are diverse; they can be fluorocarbons, perfluorinated, or biologically synthesized mono-fluorinated compounds and other possibilities. These compounds have a wide range of function and can serve as refrigerants, pharmaceuticals, agrichemicals, surfactants, ozone depletors, poisons, or pollutants. Fluorine has two isotopes, 19F and 18F; 18F being radioactive with a half-life of 110.3 min. Radioactive fluorine (18F) emits positron, which collides with an electron, called annihilation reaction and produces two photons with 511 Kev (gamma) at 180o apart. Due to the short half-life and positron emission, 18F has a very high demand and application in molecular imaging by positron emission tomography (PET).
PET is a nuclear medicine imaging technique which produces a three-dimensional image of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide, such as 18F, which is introduced into the body through a biologically active molecule. Three-dimensional images of tracer concentration within the body are then constructed by computer analysis. The most common biologically active molecule used for PET is 18F-FDG, an analogue of glucose, used for early detection of tumor. The concentrations of tracer accumulation (PET image) give tissue metabolic activity, in terms of regional glucose metabolism and accumulation. Although use of this tracer results in the most common type of PET scan, other tracer molecules are used in PET to image the tissue concentration of many other types of molecules of interest.
In this review, information on fluorination and radiofluorination reactions, radiofluoranating agents and radiolabeling of various compounds and their application in PET imaging is presented.