- Synthesis of [18 F]-γ-Fluoro-α,β-unsaturated Esters and Ketones via Vinylogous 18 F-Fluorination of α-Diazoacetates with [18 F]AgF
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This communication reports a method for the vinylogous radiofluorination of α-diazoacetates to generate [18 F]-γ-fluoro-α,β-unsaturated esters and ketones in moderate to good radiochemical yields. The method uses no-carrier-added [18 F]AgF and is compatible with aromatic and non-aromatic substrates and a number of different functional groups. The labeling method is showcased in the synthesis of a fluorinated cholest-5-en-3-one derivative as well as a difluorinated product pertinent to drug discovery.
- Brooks, Allen F.,Ichiishi, Naoko,Jackson, Isaac M.,Lee, So Jeong,Sanford, Melanie S.,Scott, Peter J. H.,Thompson, Stephen
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supporting information
p. 4401 - 4407
(2019/11/21)
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- TRIAZOLOPYRIDINE ETHER DERIVATIVES AND THEIR USE IN NEUROLOGICAL AND PYSCHIATRIC DISORDERS
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The disclosure generally relates to compounds of formula I, including their salts, as well as compositions and methods of using the compounds. The compounds modulate the mGluR2 receptor and may be useful for the treatment of various disorders of the central nervous system.
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Page/Page column 62-63
(2015/04/15)
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- β-fluoroamphetamines via the stereoselective synthesis of benzylic fluorides
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A range of substituted aryl epoxides undergo efficient ring-opening hydrofluorination upon treatment with 0.33 equiv of BF3-OEt 2 in CH2Cl2 at -20 -°C to give the corresponding syn-fluorohydrins, consistent with a mechanism involving a stereoselective SN1-type epoxide ring-opening process. The benzylic fluoride products of these reactions are valuable templates for further elaboration, as demonstrated by the preparation of a range of aryl-substituted β-fluoroamphetamines.
- Cresswell, Alexander J.,Davies, Stephen G.,Lee, James A.,Roberts, Paul M.,Russell, Angela J.,Thomson, James E.,Tyte, Melloney J.
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supporting information; experimental part
p. 2936 - 2939
(2010/09/10)
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- Fluorination with ionic liquid EMIMF(HF)2.3 as mild HF source
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Hydrogen fluoride is a basic fluorinating reagent, but handling it is difficult. For this reason, some modified fluorinating reagents such as HF-pyridine, Et3N-HF, and poly(hydrogen fluoride) complex have been developed. Those reagents, however, still require aqueous work-up procedures which generate hydrogen fluoride. Recently, ionic liquids have received much attention because of the ease in handling them and the possibility of non-aqueous work-up. An ionic liquid, 3-ethyl-1-methyimidazolium oligo hydrogen fluoride (EMIMF(HF)2.3), which is stable in air and moisture, can be used as a hydrogen fluoride equivalent for some fluorination reactions; it does not require an aqueous work-up.
- Yoshino, Hideaki,Matsumoto, Kazuhiko,Hagiwara, Rika,Ito, Yasuhiko,Oshima, Koichiro,Matsubara, Seijiro
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- Boron trifluoride-induced reactions of phenylglycidyl ethers: A convenient synthesis of enantiopure, stereodefined fluorohydrins
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Ring-opening hydrofluorination of enantiomerically pure (2S,3S)-3-arylglycidyl ethers (aryl=phenyl, 4-trifluoromethylphenyl) by boron trifluoride-diethyl ether under mild conditions provides β-fluoro alcohols in good yield in a stereospecific manner with
- Islas-González, Gabriela,Puigjaner, Cristina,Vidal-Ferran, Anton,Moyano, Albert,Riera, Antoni,Pericàs, Miquel A.
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p. 6337 - 6341
(2007/10/03)
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- A mild ring opening fluorination of epoxide with ionic liquid 1-ethyl-3-methylimidazorium oligo hydrogenfluoride (EMIMF(HF) 2.3)
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Ring opening fluorination of epoxides with hydrogen fluoride in ionic liquid 1-ethyl-3-methylimidazorium oligo hydrogenfluoride EMIMF(HF)2.3 was demonstrated. This ionic liquid released hydrogen fluoride graduately to make mild conditions witho
- Yoshino, Hideaki,Nomura, Kenichi,Matsubara, Seijiro,Oshima, Koichiro,Matsumoto, Kazuhiko,Hagiwara, Rika,Ito, Yasuhiko
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p. 1127 - 1129
(2007/10/03)
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- Regioselective synthesis of fluorohydrines via SN2-type ring-opening of epoxides with TBABF-KHF2
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We found that the ring-opening fluorination of terminal epoxides using TBABF-KHF2 proceeds with high selectivity through the SN2 mechanism. As TBABF-KHF2 is easily obtainable, is stable, and can be used in glassware, it ca
- Akiyama, Yuriko,Fukuhara, Tsuyoshi,Hara, Shoji
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p. 1530 - 1532
(2007/10/03)
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- Process for the production of fluorinated organic compounds and fluorinating agents
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A process for the production of a fluorinated organic compound, characterized by fluorinating an organic compound having a hydrogen atoms using IF5; and a novel fluorination process for fluorinating an organic compound having a hydrogen atoms by using a fluorinating agent containing IF5 and at least one member selected from the group consisting of acids, bases, salts and additives.
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- Regioselective, stereospecific, and chemoselective fluorination of epoxy alcohols: Development of fluorinating hybrid reagents, associated with Lewis acid metal fluoride/ammonium hydrogen fluoride
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A new type of fluorinating reagent of Lewis acid metal fluoride/ammonium hydrogen fluoride is developed for regio-, stereo-, and chemoselective ring opening fluorination of epoxy alcohols.
- Mikami, Koichi,Ohba, Shiho,Ohmura, Hirofumi
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- Enantioselective ring-opening of epoxides by HF-reagents: Asymmetric synthesis of fluoro lactones
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The asymmetric ring opening of meso- and racemic-epoxides with different HF-reagents mediated by enantiopure (salen)chromium chloride provides optically active fluorohydrins with maximum 90% e.e. This reaction as well as lipase-catalyzed deracemization of
- Haufe, Günter,Bruns, Stefan,Runge, Martina
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- Novel fluorination reagent: IF5/Et3N-3HF
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IF5 in Et3N-3HF was found to be a stable, non-hazardous, easy to handle, and inexpensive reagent that enables effective and selective fluorination of organic compounds under mild conditions.
- Yoneda, Norihiko,Fukuhara, Tsuyoshi
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p. 222 - 223
(2007/10/03)
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- Enantioselective introduction of fluoride into organic compounds: First asymmetric ring opening of epoxides by hydrofluorinating reagents
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The first enantioselective epoxide ring opening with hydrofluorinating agents mediated by chiral non-racemic Lewis acids is reported. The reaction of cyclohexene oxide (1) with KHF2/18-crown-6 is trans-diastereoselective and proceeds with 55% ee to form (R,R)-(-)-2-fluorocyclohexanol (2) in the presence of Jacobsen's (S,S)-(+)-(salen)chromium chloride complex A. From racemic epoxides such as styrene oxide (9) or phenyl glycidether (13), mainly or exclusively the products with fluorine in primary position are formed with 90 or 62% ee, respectively. In all cases minor amounts of corresponding chlorohydrins are formed.
- Bruns, Stefan,Haufe, Günter
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p. 247 - 254
(2007/10/03)
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- Synthesis of γ-Fluoro-α,β-unsaturated Carboxylic Esters from Saturated α-Fluoro Aldehydes
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γ-Fluoro-α,β-unsaturated carboxylic esters 7a, 7b and 7d and 4-fluoro-4-phenylbut-3-enoic ester (8) are obtained by two alternative pathways from 2-fluoro aldehydes 5a-d, either by Horner-Wadsworth-Emmons reaction or by Wittig reaction. The aldehydes 5a-d are prepared by Swern oxidation of the corresponding fluorohydrins 4a-d. These are available from α-olefins by bromofluorination, bromine-by-acetate replacement and subsequent hydrolysis.
- Oldendorf, Jens,Haufe, Gu?nter
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- Ring-opening fluorination of epoxides using hydrofluoric acid and additives
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Epoxides underwent ring-opening fluorination reaction with hydrofluoric acid in the presence of silicon fluorides and additives to give fluorohydrines in good yields.
- Shimizu, Makoto,Nakahara, Yuko
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- Potassium dihydrogen trifluoride: a novel fluorinating reagent for ring-opening of epoxides
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It has been found that potassium dihydrogen trifluoride is an efficient and easy-to-handle solid reagent for the ring-opening reaction of epoxides giving fluorhydrins regio- and stereo-selectively.The reaction proceeds via cis-addition of HF to the epoxide. - Keywords: Potassium dihydrogen trifluoride; Fluorinating reagent; Ring-opening; Epoxides; Fluorohydrin synthesis
- Tamura, Masanori,Shibakami, Motonari,Arimura, Takashi,Kurosawa, Shigeru,Sekiya, Akira
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- TETRABUTYLAMMONIUM DIHYDROGENTRIFLUORIDE: AN EFFICIENT CATALYST FOR REGIO AND STEREOSELECTIVE CONVERSION OF EPOXIDES TO FLUOROHYDRINS UNDER SOLID-LIQUID PHASE-TRANSFER CATALYSIS CONDITIONS.
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Tetrabutylammonium dihydrogentrifluoride is an efficient and easy-to-handle hydrofluorating agent in the ring-opening reaction of oxiranes to give good or excellent yields of fluorohydrins under solid-liquid PTC conditions.
- Landini, Dario,Penso, Michele
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p. 7209 - 7212
(2007/10/02)
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- The Combination of Hydrogen Fluoride Salt and Aluminium Fluoride: an Efficient Solid Reagent for Epoxide Opening to give Fluorohydrins
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The combination of hydrogen fluoride salt and porous aluminium fluoride (MHF2-AlF3) (M = alkali metal) is a stable and efficient solid reagent for promoting the ring-opening reaction of simple aliphatic oxiranes to give the fluorohydrins under sonication,
- Ichihara, Junko,Hanafusa, Terukiyo
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p. 1848 - 1850
(2007/10/02)
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- HIGHLY SELECTIVE RING OPENING OF EPOXIDES WITH SILICON TETRAFLUORIDE: PREPARATION OF FLUOROHYDRINS
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Regio-, stereo-, and chemoselective transformation of epoxides into fluorohydrins with silicone tetrafluoride is described.
- Shimizu, Makoto,Yoshioka, Hirosuke
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p. 4101 - 4104
(2007/10/02)
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