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14364 KiB

Open AccessArticle

Plasma Processing with Fluorine Chemistry for Modification of Surfaces Wettability

by Veronica Satulu, Maria Daniela Ionita, Sorin Vizireanu, Bogdana Mitu and Gheorghe Dinescu

Molecules 2016, 21(12), 1711; https://doi.org/10.3390/molecules21121711 - 13 Dec 2016

Cited by 27 | Viewed by 6556

Abstract

Using plasma in conjunction with fluorinated compounds is widely encountered in material processing. We discuss several plasma techniques for surface fluorination: deposition of fluorocarbon thin films either by magnetron sputtering of polytetrafluoroethylene targets, or by plasma-assisted chemical vapor deposition using tetrafluoroethane as a [...] Read more.

Using plasma in conjunction with fluorinated compounds is widely encountered in material processing. We discuss several plasma techniques for surface fluorination: deposition of fluorocarbon thin films either by magnetron sputtering of polytetrafluoroethylene targets, or by plasma-assisted chemical vapor deposition using tetrafluoroethane as a precursor, and modification of carbon nanowalls by plasma treatment in a sulphur hexafluoride environment. We showed that conformal fluorinated thin films can be obtained and, according to the initial surface properties, superhydrophobic surfaces can be achieved. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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1093 KiB

Open AccessArticle

A Stereocontrolled Protocol to Highly Functionalized Fluorinated Scaffolds through a Fluoride Opening of Oxiranes

by Attila Márió Remete, Melinda Nonn, Santos Fustero, Ferenc Fülöp and Loránd Kiss

Molecules 2016, 21(11), 1493; https://doi.org/10.3390/molecules21111493 - 17 Nov 2016

Cited by 12 | Viewed by 5107

Abstract

A novel selective and substrate-dependent synthetic protocol has been developed towards the synthesis of various fluorine-containing, highly functionalized cycloalkane derivatives. The method involves the stereoselective epoxidation of some unsaturated cyclic β-amino acid derivatives as model compounds, followed by a regioselective fluoride opening of [...] Read more.

A novel selective and substrate-dependent synthetic protocol has been developed towards the synthesis of various fluorine-containing, highly functionalized cycloalkane derivatives. The method involves the stereoselective epoxidation of some unsaturated cyclic β-amino acid derivatives as model compounds, followed by a regioselective fluoride opening of oxiranes under various conditions with Deoxofluor and XtalFluor-E reagents, thereby offering an insight into this new epoxide opening methodology with fluoride. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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5455 KiB

Open AccessArticle

Comparative Studies of Interactions between Fluorodihydroquinazolin Derivatives and Human Serum Albumin with Fluorescence Spectroscopy

by Yi Wang, Meiqing Zhu, Feng Liu, Xiangwei Wu, Dandan Pan, Jia Liu, Shisuo Fan, Zhen Wang, Jun Tang, Risong Na, Qing X. Li, Rimao Hua and Shangzhong Liu

Molecules 2016, 21(10), 1373; https://doi.org/10.3390/molecules21101373 - 14 Oct 2016

Cited by 18 | Viewed by 5272

Abstract

In the present study, 3-(fluorobenzylideneamino)-6-chloro-1-(3,3-dimethylbutanoyl)-phenyl-2,3-dihydroquinazolin-4(1H)-one (FDQL) derivatives have been designed and synthesized to study the interaction between fluorine substituted dihydroquinazoline derivatives with human serum albumin (HSA) using fluorescence, circular dichroism and Fourier transform infrared spectroscopy. The results indicated that the FDQL [...] Read more.

In the present study, 3-(fluorobenzylideneamino)-6-chloro-1-(3,3-dimethylbutanoyl)-phenyl-2,3-dihydroquinazolin-4(1H)-one (FDQL) derivatives have been designed and synthesized to study the interaction between fluorine substituted dihydroquinazoline derivatives with human serum albumin (HSA) using fluorescence, circular dichroism and Fourier transform infrared spectroscopy. The results indicated that the FDQL could bind to HSA, induce conformation and the secondary structure changes of HSA, and quench the intrinsic fluorescence of HSA through a static quenching mechanism. The thermodynamic parameters, ΔH, ΔS, and ΔG, calculated at different temperatures, revealed that the binding was through spontaneous and hydrophobic forces and thus played major roles in the association. Based on the number of binding sites, it was considered that one molecule of FDQL could bind to a single site of HSA. Site marker competition experiments indicated that the reactive site of HSA to FDQL mainly located in site II (subdomain IIIA). The substitution by fluorine in the benzene ring could increase the interactions between FDQL and HSA to some extent in the proper temperature range through hydrophobic effect, and the substitution at meta-position enhanced the affinity greater than that at para- and ortho-positions. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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10300 KiB

Open AccessArticle

Effects of (Oxy-)Fluorination on Various High-Performance Yarns

by Iris Kruppke, Matthias Bartusch, Rico Hickmann, Rolf-Dieter Hund and Chokri Cherif

Molecules 2016, 21(9), 1127; https://doi.org/10.3390/molecules21091127 - 26 Aug 2016

Cited by 8 | Viewed by 5700

Abstract

In this work, typical high-performance yarns are oxy-fluorinated, such as carbon fibers, ultra-high-molecular-weight polyethylene, poly(p-phenylene sulfide) and poly(p-phenylene terephthalamide). The focus is on the property changes of the fiber surface, especially the wetting behavior, structure and chemical composition. Therefore, [...] Read more.

In this work, typical high-performance yarns are oxy-fluorinated, such as carbon fibers, ultra-high-molecular-weight polyethylene, poly(p-phenylene sulfide) and poly(p-phenylene terephthalamide). The focus is on the property changes of the fiber surface, especially the wetting behavior, structure and chemical composition. Therefore, contact angle, XPS and tensile strength measurements are performed on treated and untreated fibers, while SEM is utilized to evaluate the surface structure. Different results for the fiber materials are observed. While polyethylene exhibits a relevant impact on both surface and bulk properties, polyphenylene terephthalamide and polyphenylene sulfide are only affected slightly by (oxy-)fluorination. The wetting of carbon fiber needs higher treatment intensities, but in contrast to the organic fibers, even its textile-physical properties are enhanced by the treatment. Based on these findings, the capability of (oxy-)fluorination to improve the adhesion of textiles in fiber-reinforced composite materials can be derived. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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2895 KiB

Open AccessArticle

Fluorinated Polyurethanes, Synthesis and Properties

by Olga Smirnova, Alexey Glazkov, Alexander Yarosh and Alexey Sakharov

Molecules 2016, 21(7), 904; https://doi.org/10.3390/molecules21070904 - 12 Jul 2016

Cited by 15 | Viewed by 6579

Abstract

Fluorinated polyurethanes with a glass transition temperature as low as −139 °C and a decomposition onset temperature of 247–330 °C were prepared by a reaction of fluorinated alcohols with aromatic and cycloaliphatic diisocyanates in solution or melt. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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398 KiB

Open AccessArticle

Synthesis of Regiospecifically Fluorinated Conjugated Dienamides

by Mohammad Chowdhury, Samir K. Mandal, Shaibal Banerjee and Barbara Zajc

Molecules 2014, 19(4), 4418-4432; https://doi.org/10.3390/molecules19044418 - 10 Apr 2014

Cited by 11 | Viewed by 6236

Abstract

Modular synthesis of regiospecifically fluorinated 2,4-diene Weinreb amides, with defined stereochemistry at both double bonds, was achieved via two sequential Julia-Kocienski olefinations. In the first step, a Z-a-fluorovinyl Weinreb amide unit with a benzothiazolylsulfanyl substituent at the allylic position was assembled. This [...] Read more.

Modular synthesis of regiospecifically fluorinated 2,4-diene Weinreb amides, with defined stereochemistry at both double bonds, was achieved via two sequential Julia-Kocienski olefinations. In the first step, a Z-a-fluorovinyl Weinreb amide unit with a benzothiazolylsulfanyl substituent at the allylic position was assembled. This was achieved via condensation of two primary building blocks, namely 2-(benzo[d]thiazol-2-ylsulfonyl)-2-fluoro-N-methoxy-N-methylacetamide (a Julia-Kocienski olefination reagent) and 2-(benzo[d]thiazol-2-ylthio)acetaldehyde (a bifunctional building block). This condensation was highly Z-selective and proceeded in a good 76% yield. Oxidation of benzothiazolylsulfanyl moiety furnished a second-generation Julia-Kocienski olefination reagent, which was used for the introduction of the second olefinic linkage via DBU-mediated condensations with aldehydes, to give (2Z,4E/Z)-dienamides in 50%–74% yield. Although olefinations were 4Z-selective, (2Z,4E/Z)-2-fluoro-2,4-dienamides could be readily isomerized to the corresponding 5-substituted (2Z,4E)-2-fluoro-N-methoxy-N-methylpenta-2,4-dienamides in the presence of catalytic iodine. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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237 KiB

Open AccessArticle

Pauson-Khand Reaction of Internal Dissymmetric Trifluoromethyl Alkynes. Influence of the Alkene on the Regioselectivity

by Nuria Aiguabella, Elsa M. Arce, Carlos Del Pozo, Xavier Verdaguer and Antoni Riera

Molecules 2014, 19(2), 1763-1774; https://doi.org/10.3390/molecules19021763 - 3 Feb 2014

Cited by 8 | Viewed by 6723

Abstract

The scope of the Pauson-Khand reaction (PKR) of internal trifluoromethyl alkynes, previously described with norbornadiene, is expanded to norbornene and ethylene. A thorough structural analysis of the resulting PK adducts has been carried out to unveil that α-trifluoromethylcyclopentenones are preferred in all cases, [...] Read more.

The scope of the Pauson-Khand reaction (PKR) of internal trifluoromethyl alkynes, previously described with norbornadiene, is expanded to norbornene and ethylene. A thorough structural analysis of the resulting PK adducts has been carried out to unveil that α-trifluoromethylcyclopentenones are preferred in all cases, independently of the electronic properties of the alkyne. The regioselectivity observed with norbornadiene and ethylene is higher than in the case of norbornene. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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776 KiB

Open AccessArticle

Crystal Structures and Antifungal Activities of Fluorine-Containing Thioureido Complexes with Nickel(II)

by Chun Li, Wen Yang, Huanhuan Liu, Mengying Li, Weiqun Zhou and Juan Xie

Molecules 2013, 18(12), 15737-15749; https://doi.org/10.3390/molecules181215737 - 17 Dec 2013

Cited by 12 | Viewed by 5558

Abstract

Ni(II) complexes with N-2-fluorobenzoylpiperidine-1-carbothioimidate (L2⁻), N-4-fluorobenzoylpiperidine-1-carbothioimidate (L3⁻), N-2-fluorobenzoylmorpholine- 1-carbothioimidate (L5⁻) and N-4-fluorobenzoylmorpholine-1-carbothioimidate (L6⁻) have been synthesized and characterized by elemental analysis, FTIR and ¹H-NMR. The crystal structures of three ligands (HL2, HL3 [...] Read more.

Ni(II) complexes with N-2-fluorobenzoylpiperidine-1-carbothioimidate (L2⁻), N-4-fluorobenzoylpiperidine-1-carbothioimidate (L3⁻), N-2-fluorobenzoylmorpholine- 1-carbothioimidate (L5⁻) and N-4-fluorobenzoylmorpholine-1-carbothioimidate (L6⁻) have been synthesized and characterized by elemental analysis, FTIR and ¹H-NMR. The crystal structures of three ligands (HL2, HL3 and HL6) and the corresponding Ni(II) complexes ([Ni(L2)₂], [Ni(L3)₂] and [Ni(L6)₂]) have been determined by X-ray diffraction. The antifungal activities of the Ni(II) complexes together and the corresponding ligands against the fungi Botrytis cinerea, Trichoderma spp., Myrothecium and Verticillium spp. have been investigated. The experimental results showed that the ligands and their complexes have antifungal abilities. When the fluorine was substituted on the para-benzoyl moiety, the antifungal activity of the ligands was obviously increased. Moreover, the ligands were stronger than their complexes in inhibiting fungal activities. The antifungal ability of HL6 is especially strong, and similar to that of the commercial fungicide fluconazole. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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300 KiB

Open AccessArticle

Synthesis of δ-Oxo-1,1-bis(triflyl)alkanes and Their Acidities

by Hikaru Yanai, Masaya Fujita, Arata Takahashi, Min Zhang, Masaaki Mishima, Akira Kotani, Takashi Matsumoto and Takeo Taguchi

Molecules 2013, 18(12), 15531-15540; https://doi.org/10.3390/molecules181215531 - 13 Dec 2013

Cited by 8 | Viewed by 5638

Abstract

The reaction of 1,1-bis(triflyl)ethylene generated in situ with enolizable carbonyls yielded δ-oxo-1,1-bis(triflyl)alkane derivatives. Their acidities in both the gas and solution phases were determined. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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1621 KiB

Open AccessArticle

Automated Solid-Phase Radiofluorination Using Polymer-Supported Phosphazenes

by Bente Mathiessen and Fedor Zhuravlev

Molecules 2013, 18(9), 10531-10547; https://doi.org/10.3390/molecules180910531 - 30 Aug 2013

Cited by 11 | Viewed by 6303

Abstract

The polymer supported phosphazene bases PS-P₂^tBu and the novel PS-P₂^PEG allowed for efficient extraction of [¹⁸F]F⁻ from proton irradiated [¹⁸O]H₂O and subsequent radiofluorination of a broad range of substrates directly [...] Read more.

The polymer supported phosphazene bases PS-P₂^tBu and the novel PS-P₂^PEG allowed for efficient extraction of [¹⁸F]F⁻ from proton irradiated [¹⁸O]H₂O and subsequent radiofluorination of a broad range of substrates directly on the resin. The highest radiochemical yields were obtained with aliphatic sulfonates (69%) and bromides (42%); the total radiosynthesis time was 35–45 min. The multivariate analysis showed that the radiochemical yields and purities were controlled by the resin load, reaction temperature, and column packing effects. The resins could be reused several times with the same or different substrates. The fully automated on-column radiofluorination methodology was applied to the radiosynthesis of the important PET radiotracers [¹⁸F]FLT and [¹⁸F]FDG. The latter was produced with 40% yield on a 120 GBq scale and passed GMP-regulated quality control required for commercial production of [¹⁸F]FDG. The combination of compact form factor, simplicity of [¹⁸F]F⁻ recovery and processing, and column reusability can make solid phase radiofluorination an attractive radiochemistry platform for the emerging dose-on-demand instruments for bedside production of PET radiotracers. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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706 KiB

Open AccessArticle

Design and Synthesis of New N-(5-Trifluoromethyl)-1H-1,2,4-triazol-3-yl Benzenesulfonamides as Possible Antimalarial Prototypes

by Nubia Boechat, Luiz C.S. Pinheiro, Osvaldo A. Santos-Filho and Isabor C. Silva

Molecules 2011, 16(9), 8083-8097; https://doi.org/10.3390/molecules16098083 - 20 Sep 2011

Cited by 54 | Viewed by 9812

Abstract

A rational approach was used to synthesize a new set of 15 1H-1,2,4-triazol-3-yl benzenesulfonamide derivatives with the aim of developing new antimalarial lead compounds. These derivatives were prepared in yields between 50% and 62%, and their structures were elucidated using IR, [...] Read more.

A rational approach was used to synthesize a new set of 15 1H-1,2,4-triazol-3-yl benzenesulfonamide derivatives with the aim of developing new antimalarial lead compounds. These derivatives were prepared in yields between 50% and 62%, and their structures were elucidated using IR, ¹H-, ¹³C-, ¹⁹F-NMR, MS and elemental analysis. A docking study based on sulfonamides previously used against malaria identified trifluoromethyl-substituted derivatives to be the best lead compounds for new antimalarial drug development. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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402 KiB

Open AccessCommunication

Synthesis of No-Carrier-Added 4-[¹⁸F]Fluorophenol from 4-Benzyloxyphenyl-(2-thienyl)iodonium Bromide

by Tobias L. Ross, Johannes Ermert and Heinz H. Coenen

Molecules 2011, 16(9), 7621-7626; https://doi.org/10.3390/molecules16097621 - 6 Sep 2011

Cited by 15 | Viewed by 5309

Abstract

4-[¹⁸F]Fluorophenol is a versatile synthon for the synthesis of more complex radiopharmaceuticals bearing a 4-[¹⁸F]fluorophenoxy moiety. In order to prepare 4-[¹⁸F]fluorophenol in no-carrier-added (n.c.a.) form only a nucleophilic labelling method starting from [¹⁸F]fluoride is suitable. [...] Read more.

4-[¹⁸F]Fluorophenol is a versatile synthon for the synthesis of more complex radiopharmaceuticals bearing a 4-[¹⁸F]fluorophenoxy moiety. In order to prepare 4-[¹⁸F]fluorophenol in no-carrier-added (n.c.a.) form only a nucleophilic labelling method starting from [¹⁸F]fluoride is suitable. In this paper a new, two step radiosynthesis starting from 4-benzyloxyphenyl-(2-thienyl)iodonium bromide and [¹⁸F]fluoride with subsequent deprotection is described, yielding n.c.a. [¹⁸F]fluorophenol in 34 to 36% radiochemical yield. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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616 KiB

Open AccessArticle

t-Bu₂SiF-Derivatized D₂-Receptor Ligands: The First SiFA-Containing Small Molecule Radiotracers for Target-Specific PET-Imaging

by Ljuba Iovkova-Berends, Carmen Wängler, Thomas Zöller, Georg Höfner, Klaus Theodor Wanner, Christian Rensch, Peter Bartenstein, Alexey Kostikov, Ralf Schirrmacher, Klaus Jurkschat and Björn Wängler

Molecules 2011, 16(9), 7458-7479; https://doi.org/10.3390/molecules16097458 - 2 Sep 2011

Cited by 17 | Viewed by 9061

Abstract

The synthesis, radiolabeling and in vitro evaluation of new silicon-fluoride acceptor (SiFA) derivatized D₂-receptor ligands is reported. The SiFA-technology simplifies the introduction of fluorine-18 into target specific biomolecules for Positron-Emission-Tomography (PET). However, one of the remaining challenges, especially for small molecules [...] Read more.

The synthesis, radiolabeling and in vitro evaluation of new silicon-fluoride acceptor (SiFA) derivatized D₂-receptor ligands is reported. The SiFA-technology simplifies the introduction of fluorine-18 into target specific biomolecules for Positron-Emission-Tomography (PET). However, one of the remaining challenges, especially for small molecules such as receptor-ligands, is the bulkiness of the SiFA-moiety. We therefore synthesized four Fallypride SiFA-conjugates derivatized either directly at the benzoic acid ring system (SiFA-DMFP, SiFA-FP, SiFA-DDMFP) or at the butyl-side chain (SiFA-M-FP) and tested their receptor affinities. We found D₂-receptor affinities for all compounds in the nanomolar range (K_i(SiFA-DMFP) = 13.6 nM, K_i(SiFA-FP) = 33.0 nM, K_{i(SiFA-DDMFP)} = 62.7 nM and K_i(SiFA-M-FP) = 4.21 nM). The radiofluorination showed highest yields when 10 nmol of the precursors were reacted with [¹⁸F]fluoride/TBAHCO₃ in acetonitrile. After a reversed phased cartridge purification the desired products could be isolated as an injectable solution after only 10 min synthesis time with radiochemical yields (RCY) of more than 40% in the case of SiFA-DMFP resulting in specific activities >41 GBq/µmol (>1,100 Ci/mmol). Furthermore, the radiolabeled products were shown to be stable in the injectable solutions, as well as in human plasma, for at least 90 min. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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932 KiB

Open AccessArticle

Perfluoro Allyl Fluorosulfate (FAFS): A Versatile Building Block for New Fluoroallylic Compounds

by Ivan Wlassics, Vito Tortelli, Serena Carella, Cristiano Monzani and Giuseppe Marchionni

Molecules 2011, 16(8), 6512-6540; https://doi.org/10.3390/molecules16086512 - 4 Aug 2011

Cited by 15 | Viewed by 8371

Abstract

In this study we will present and discuss both the synthesis of CF₂=CFCF₂OSO₂F (perfluoroallyl fluorosulfate, FAFS), focusing in particular on the important role of C₃F₆/SO₃ ratio, reaction temperature and boron catalyst/SO₃ [...] Read more.

In this study we will present and discuss both the synthesis of CF₂=CFCF₂OSO₂F (perfluoroallyl fluorosulfate, FAFS), focusing in particular on the important role of C₃F₆/SO₃ ratio, reaction temperature and boron catalyst/SO₃ ratio on FAFS’ yield and selectivity, as well as a wide variety of ionic and radical reactions possible with FAFS. We focused our attention on reactions of FAFS with aliphatic and aromatic alcohols, acyl halides, halides, H₂O₂, ketones and radicals whose synthesis and reaction mechanisms will be presented and discussed. Particular attention will be devoted to the novel diallyl-fluoroalkyl peroxide obtained. Factors such as pK_a and Lowry and Pearson’s Hard/Soft Acid-Base Theory which determine the selectivity between Addition/Elimination vs. Nucleophilic Substitution reaction mechanisms on FAFS will also be presented and discussed. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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258 KiB

Open AccessArticle

Dehydration of (Perfluoroalkyl)tetramethylcyclopentenols

by Jan Čermák, Thu Huong Nguyen Thi, Jaroslav Včelák and Alena Krupková

Molecules 2011, 16(5), 4031-4044; https://doi.org/10.3390/molecules16054031 - 17 May 2011

Cited by 2 | Viewed by 5481

Abstract

(Perfluoroalkyl) tetramethylcyclopentenols (alkyl = n-butyl, n-hexyl, n-octyl) were dehydrated to a complex mixture of endo, endo-(perfluoroalkyl) tetramethyl-cyclopentadienes and their endo-, exo-isomers. It was found in preliminary screening experiments that the best reagent for this transformation, giving an 89% [...] Read more.

(Perfluoroalkyl) tetramethylcyclopentenols (alkyl = n-butyl, n-hexyl, n-octyl) were dehydrated to a complex mixture of endo, endo-(perfluoroalkyl) tetramethyl-cyclopentadienes and their endo-, exo-isomers. It was found in preliminary screening experiments that the best reagent for this transformation, giving an 89% yield of isomeric product mixture, was P₂O₅ in benzene at 80-90 °C. Products were characterized on the basis of their mass spectra and retention time information, and some peaks in the mass spectra were identified from their molecular fragments. Structures were assigned to the three most abundant products of (perfluorohexyl)tetramethylcyclopentenol dehydration. Formal dehydration kinetics showed a second order reaction in benzene but zeroth order with induction period in chlorobenzene, suggesting mass transfer limitations in the more polar chlorobenzene. Some of the products were formed by consecutive isomerization of the others, as shown by the kinetic analysis. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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250 KiB

Open AccessArticle

General Pathway for a Convenient One-Pot Synthesis of Trifluoromethyl-Containing 2-amino-7-alkyl(aryl/heteroaryl)-1,8-naphthyridines and Fused Cycloalkane Analogues

by Helio G. Bonacorso, Rosália Andrighetto, Nícolas Krüger, Nilo Zanatta and Marcos A. P. Martins

Molecules 2011, 16(4), 2817-2832; https://doi.org/10.3390/molecules16042817 - 30 Mar 2011

Cited by 14 | Viewed by 9869

Abstract

A convenient and general method for the synthesis in 26–73% yields of a new series of 7-alkyl(aryl/heteroaryl)-2-amino-5-trifluoromethyl-1,8-naphthyridines from direct cyclocondensation reactions of 4-alkoxy-1,1,1-trifluoroalk-3-en-2-ones [CF₃C(O)CH=C(R¹)OR, where R¹= H, Me, Ph, 4-MePh, 4-OMePh, 4-FPh, 4-BrPh, 4-NO₂Ph, 2-furyl, [...] Read more.

A convenient and general method for the synthesis in 26–73% yields of a new series of 7-alkyl(aryl/heteroaryl)-2-amino-5-trifluoromethyl-1,8-naphthyridines from direct cyclocondensation reactions of 4-alkoxy-1,1,1-trifluoroalk-3-en-2-ones [CF₃C(O)CH=C(R¹)OR, where R¹= H, Me, Ph, 4-MePh, 4-OMePh, 4-FPh, 4-BrPh, 4-NO₂Ph, 2-furyl, 2-thienyl and R = Me, Et] with 2,6-diaminopyridine (2,6-DAP), under mild conditions, is described. Another synthetic route also allowed the synthesis of 2-amino-5-trifluoromethyl-cycloalka[b][1,8]naphthyridines in 33–36% yields, from direct or indirect cyclo-condensation reactions of five-, six- and seven-membered 2-trifluoroacetyl-1-methoxy-cycloalkenes with 2,6-DAP. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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Review

Jump to: Research

1157 KiB

Open AccessReview

Recent Advances in the Application of Selectfluor^TMF-TEDA-BF₄ as a Versatile Mediator or Catalyst in Organic Synthesis

by Stojan Stavber

Molecules 2011, 16(8), 6432-6464; https://doi.org/10.3390/molecules16086432 - 29 Jul 2011

Cited by 83 | Viewed by 11836

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 reagents for electrophilic fluorination, but as a strong oxidant is also a convenient mediator or catalyst of several “fluorine-free” functionalizations of organic compounds. Its applications as [...] Read more.

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 reagents for electrophilic fluorination, but as a strong oxidant is also a convenient mediator or catalyst of several “fluorine-free” functionalizations of organic compounds. Its applications as a mediator in transformations of oxidizable functional groups or gold-catalyzed C-C and C-heteroatom oxidative coupling reactions, a catalyst in formation of various heterocyclic rings, a reagent or catalyst of various functionalizations of electron-rich organic compounds (iodination, bromination, chlorination, nitration, thiocyanation, sulfenylation, alkylation, alkoxylation), a catalyst of one-pot-multi-component coupling reactions, a catalyst of regioselective ring opening of epoxides, a deprotection reagent for various protecting groups, and a mediator for stereoselective rearrangement processes of bicyclic compounds are reviewed and discussed. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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