- Multi-faceted reactivity of N-fluorobenzenesulfonimide (NFSI) under mechanochemical conditions: fluorination, fluorodemethylation, sulfonylation, and amidation reactions
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In the search for versatile reagents compatible with mechanochemical techniques, in this work we studied the reactivity of N-fluorobenzenesulfonimide (NFSI) by ball milling. We corroborated that, by mechanochemistry, NFSI can engage in a variety of reactions such as fluorinations, fluorodemethylations, sulfonylations, and amidations. In comparison to the protocols reported in solution, the mechanochemical reactions were accomplished in the absence of solvents, in short reaction times, and in yields comparable to or higher than their solvent-based counterparts.
- Ardila-Fierro, Karen J.,Bari?i?, Dajana,Geneste, Hervé,Hernández, José G.
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supporting information
p. 182 - 189
(2022/03/01)
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- 8-FLUORO-4-ALKYLUMBELLIFERYL ALPHA-D-GLUCOPYRANOSIDE, BIOLOGICAL STERILIZATION INDICATOR INCLUDING THE SAME AND ITS USE IN A METHOD OF DETERMINING EFFICACY OF A STERILIZATION PROCESS
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A self-contained biological sterilization indicator comprises: a housing; bacterial spores comprising, and/or capable of producing, an enzyme capable of catalyzing cleavage of an enzyme substrate; and a frangible container containing a composition, wherein the composition comprises the enzyme substrate, wherein if the frangible container is broken the composition will contact the bacterial spores to form a mixture having an initial pH in the range from 6.0 to 9.0. The enzyme substrate comprises a fluorinated 4'-alkylumbelliferyl α-D-glucopyranoside represented by the structural formula (I), wherein R is an alkyl group having from 1 to 12 carbon atoms. A biological sterilization indicator comprising a kit containing isolated components comprising (i) bacterial spores comprising, and/or capable of producing, an enzyme capable of catalyzing cleavage of the enzyme substrate and a method of assessing efficacy of a sterilization process are also disclosed.
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- AROMATIC-SUBSTITUTED XANTHENE DYE
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PROBLEM TO BE SOLVED: To provide a useful compound used for independent detection of multiple spatially overlapping analytes in a mixture, for example, single-tube multiplex DNA probe assays, immunoassays, multicolor DNA sequencing methods and the like. SOLUTION: There is provided an aromatic-substituted xanthene dye represented by the following formula. (Y1 and Y2 each independently represents hydroxyl, oxygen, iminium, a linking group or an amine; Y1 forms a cyclic amine together with R2 or Y2 forms a cyclic amine together with R3; R2, R3, R5 and R7 each independently represents H, F, Cl, a lower alkyl, a lower alkene, sulfonate, sulfone, iminium, amide, nitrile, a lower alkoxy, phenyl or a linking group; R1 represents a single ring or a polycyclic aromatic or the like; R4 represents H, F, alkyl, amino or the like; and R6 represents acetylene, a lower alkyl or the like.) COPYRIGHT: (C)2015,JPO&INPIT
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Paragraph 0194
(2016/12/22)
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- Turnover Is rate-limited by deglycosylation for micromonospora viridifaciens sialidase-catalyzed hydrolyses: Conformational implications for the Michaelis complex
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A panel of seven isotopically substituted sialoside natural substrate analogues based on the core structure 7-(5-acetamido-3,5-dideoxy-d-glycero- α-d-galacto-non-2-ulopyranosylonic acid)-(2→6)-β-d- galactopyranosyloxy)-8-fluoro-4-methylcoumarin (1, Neu5Acα2,6GalβFMU) have been synthesized and used to probe the rate-limiting step for turnover by the M. viridifaciens sialidase. The derived kinetic isotope effects (KIEs) on kcat for the ring oxygen (18V), leaving group oxygen (18V), anomeric carbon (13V), C3-carbon (13V), C3-R deuterium (DVR), C3-S deuterium (DV S), and C3-dideuterium (D2V) are 0.986 ± 0.003, 1.003 ± 0.005, 1.021 ± 0.006, 1.001 ± 0.008, 1.029 ± 0.007, 0.891 ± 0.008, and 0.890 ± 0.006, respectively. The solvent deuterium KIE (D2OV) for the sialidase-catalyzed hydrolysis of 1 is 1.585 ± 0.004. In addition, a linear proton inventory was measured for the rate of hydrolysis, under saturating condition, as a function of n, the fraction of deuterium in the solvent. These KIEs are compatible with rate-determining cleavage of the enzymatic tyrosinyl β-sialoside intermediate. Moreover, the secondary deuterium KIEs are consistent with the accumulating Michaelis complex in which the sialosyl ring of the carbohydrate substrate is in a 6S2 skew boat conformation. These KIE measurements are also consistent with the rate-determining deglycosylation reaction occurring via an exploded transition state in which synchronous charge delocalization is occurring onto the ring oxygen atom. Finally, the proton inventory and the magnitude of the solvent KIE are consistent with deglycosylation involving general acid-catalyzed protonation of the departing tyrosine residue rather than general base-assisted attack of the nucleophilic water.
- Chan, Jefferson,Lu, April,Bennet, Andrew J.
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p. 2989 - 2997
(2011/04/25)
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- Transformations of organic molecules with F-TEDA-BF4 in ionic liquid media
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The transformations of organic molecules with F-TEDA-BF4 (1) were investigated in the hydrophilic ionic liquid (IL) 1-butyl-3-methyl- imidazolium tetrafluoroborate ([bmim][BF4], 2) and the hydrophobic IL 1-butyl-3-methyl-imidazolium hexafluorophosphate ([bmim][PF6], 3). The range of substrates included alkyl substituted phenols 4a-c, 9, 13, 1,1-diphenylethene (15), alkyl aryl ketones 19-22, aldehydes 23-25 and methoxy-substituted benzene derivatives 26-30. The evaluation of the outcome of reactions performed in IL media in comparison to those of the corresponding reactions in conventional organic solvents revealed that the transformations in IL are less efficient and selective. The effect of the presence of a nucleophile (MeOH, H2O, MeCN) on the course of reaction was also studied.
- Pavlinac, Jasminka,Zupan, Marko,Stavber, Stojan
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experimental part
p. 2394 - 2409
(2009/12/03)
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- Synthesis and heme-binding correlation with antimalarial activity of 3,6-bis-(ω-N,N-diethylaminoamyloxy)-4,5-difluoroxanthone
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In this study, the effect of fluorine upon the heme-binding ability of the xanthone nucleus was investigated for 3,6-bis-(ω-N,N-diethylaminoamyloxy)-4,5-difluoroxanthone (F2C5). 2-Fluoro-1,3-dimethoxybenzene was prepared by a new, improved method and used to build up the xanthone nucleus. The interaction of F2C5 with heme was investigated by UV-vis, 1H NMR, and 19F NMR spectroscopy. For the first time, NMR studies for the heme-drug interactions are carried out at pH 5.0, physiological for the acidic food vacuole of the malaria parasite.
- Dodean, Rozalia A.,Kelly, Jane X.,Peyton, David,Gard, Gary L.,Riscoe, Michael K.,Winter, Rolf W.
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p. 1174 - 1183
(2008/09/17)
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- Preparation process of fluorine substituted aromatic compound
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A preparation process of a fluorine substituted aromatic compound comprising reacting an alkali metal or alkali earth metal salt of an aromatic compound having a hydroxy group with an organic fluorinating agent is disclosed. As a representative fluorinating agent, a bis-dialkylamino-difluoromethane compound, for example, 2,2′-difluoro-1,3-dimethylimidazolidine, is exemplified. According to the process, an industrially useful fluorinated aromatic compound, for example, a fluorobenzene, a fluorine substituted benzophenone, a fluorine substituted diarylsulfone can be prepared with ease in economy without specific equipment.
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- Fluorinated xanthene derivatives
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The family of dyes of the invention are fluoresceins and rhodols that are directly substituted on one or more aromatic carbons by fluorine. These fluorine-substituted fluorescent dyes possess greater photostability and have lower sensitivity to pH changes in the physiological range of 6-8 than do non-fluorinated dyes, exhibit less quenching when conjugated to a substance, and possess additional advantages. The dyes of the invention are useful as detectable tracers and for preparing conjugates of organic and inorganic substances.
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- Synthesis of fluorinated fluoresceins
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Several novel fluorinated fluoresceins (Oregon Green dyes) were prepared by the reaction of fluororesorcinols with phthalic anhydride and its derivatives. A novel regiospecific synthesis of fluororesorcinols was key to the successful synthesis of these new fluorophores. (Polyfluoro)- nitrobenzenes were reacted with 2 equiv of sodium methoxide followed by reduction, hydrodediazoniation, and demethylation, giving the first straightforward synthesis of 2-fluororesorcinol, 4-fluororesorcinol, 2,4- difluororesorcinol, and 2,4,5-trifluororesorcinol. These fluorinated fluoresceins have higher photostability and ionize at a lower pH (pK(a) = 3.3-6.1) than fluorescein (pK(a) = 6.5). Some of the fluorinated fluoresceins have very high quantum yields (0.85-0.97), which, in combination with their lower pK(a)s and high photostability, makes them superior fluorescent dyes for use as reporter molecules in biological systems.
- Sun, Wei-Chuan,Gee, Kyle R.,Klaubert, Dieter H.,Haugland, Richard P.
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p. 6469 - 6475
(2007/10/03)
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