79069-70-8Relevant articles and documents
Shielding Effect of Micelle for Highly Effective and Selective Monofluorination of Indoles in Water
Bora, Pranjal P.,Bihani, Manisha,Plummer, Scott,Gallou, Fabrice,Handa, Sachin
, p. 3037 - 3042 (2019/04/01)
Highly selective direct monofluorination of indoles and arenes was developed through an approach that allows site-specific solubility of substrate and fluorine source in the micelle. This approach was highly selective for a broad range of substrates with excellent functional group tolerance. Differences in binding constant and solubility of indoles and arenes in the micelle allowed the fine-tuning of selectivity. Control experiments suggested a radical pathway and provided insight into the role of micelles of the environmentally benign amphiphile PS-750-M. Dynamic light scattering experiments strongly indicated the site-specific solubility of the substrate and fluorine source. The methodology was successfully adapted to gram scale, and the E-factor established from a recycle study indicated that the process is environmentally responsible and sustainable.
Transformations of organic molecules with F-TEDA-BF4 in ionic liquid media
Pavlinac, Jasminka,Zupan, Marko,Stavber, Stojan
experimental part, p. 2394 - 2409 (2009/12/03)
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.
Solvent-free fluorination of organic compounds using N-F reagents
Stavber, Gaj,Zupan, Marko,Stavber, Stojan
, p. 2671 - 2673 (2008/02/03)
Efficient fluorination of 1,3-dicarbonyl compounds, enol acetates of aromatic ketones, and activated aromatic compounds was achieved under solvent-free conditions using Selectfluor F-TEDA-BF4 or Accufluor NFSi.
FACILE PREPARATIONS OF 4-FLUORORESORCINOL
Belanger, Patrice C.,Lau, C. K.,Williams, Haydn W. R.,Dufresne, C.,Scheigetz, John
, p. 1479 - 1482 (2007/10/02)
Two facile methods for preparing 4-fluororesorcinol have been developed.In the first method, the direct fluorination of 1,3-dimethoxybenzene with trifluoromethyl hypofluorite carried out in Freon 11 at -78 deg C afforded 2,4-dimethoxyfluorobenzene.Demethylation by heating under reflux in 48percent HBr in acetic acid gave 4-fluororesorcinol in an overall yield of 60percent.The second method involved the fluorination of 2,6-dimethoxycetophenone by trifluoromethyl hypofluorite in Freon 11 at -78 deg C, leading to 2,6-dimethoxy-3-fluorocetophenone.On heating under reflux in 48percent HBr in acetic acid, 4-fluororesorcinol was obtained in an overall yield of 74percent.The latter is the method of choice for preparing 4-fluororesorcinol.
A Novel Electrophilic Fluorination of Activated Aromatic Rings Using Acetyl Hypofluorite, Suitable also for Introducing (18)F into Benzene Nuclei
Lerman, Ori,Yitzhak, Tor,Hebel, David,Rozen, Shlomo
, p. 806 - 813 (2007/10/02)
Acetyl hypofluorite (1) is a new compound that serves as a novel electrophilic fluorinating agent.It is special in the sense that, while it is very reactive, it is still a milder reagent than other fluoroxy compounds such as CF3OF or CF3COOF.It is synthesized directly from elemental fluorine and is used without any isolation or purification.The hypofluorite 1 reacts efficiently and selectively with activated aromatic rings,particularly phenol and aniline derivatives after suitable protection of the hydroxyl and the amino groups.The net result of the reaction is partly according to classical aromatic electrophilic substitution.Unlike such a substitution, however, the electrophilic fluorine atom of 1 substitutes mainly an ortho hydrogen and only occasionally small amounts of p-fluoro derivatives are found.Evidence supports the mechanism for this aromatic fluorination as being mainly an addition-elimination one.In many cases the electrophilic aromatic fluorinations can replace the classical 60-year-old Balz-Schiemann method, which until today is probably the most used procedure.Since aromatic fluorination with 1 is a very fast reaction and since 1 is produced directly from elemental fluorine, this is probably one of the best ways for introduction of the short-living radioisotope (18)F into activated aromatic rings.This will greatly encourage the synthesis of compounds suitable for use in the rapidly developing field of positron emitting transaxial tomography, which in itself depends on the efficient and easy supply of compounds possessing positron emitting isotopes.
Acetyl Hypofluorite as a Taming Carrier of Elemental Fluorine for Novel Electrophilic Fluorination of Activated Aromatic Rings
Lerman, Ori,Tor, Yitzhak,Rozen, Shlomo
, p. 4629 - 4631 (2007/10/02)
The new fluorinating reagent CH3COOF, which is prepared in situ from F2, is used for electrophilic aromatic fluorinations of activated aromatic rings.
