77976-08-0Relevant articles and documents
Deoxyfluorination of Carboxylic Acids with CpFluor: Access to Acyl Fluorides and Amides
Wang, Xiu,Wang, Fei,Huang, Fengfeng,Ni, Chuanfa,Hu, Jinbo
supporting information, p. 1764 - 1768 (2021/03/03)
3,3-Difluoro-1,2-diphenylcyclopropene (CpFluor), a bench-stable fluorination reagent, has been developed in the deoxyfluorination of carboxylic acids to afford various acyl fluorides. This all-carbon-based fluorination reagent enabled the efficient transformation of (hetero)aryl, alkyl, alkenyl, and alkynyl carboxylic acids to the corresponding acyl fluorides under the neutral conditions. This deoxyfluorination method was featured by the synthesis of acyl fluorides with in-situ formed CpFluor, as well as the one-pot amidation reaction of carboxylic acids via in-situ formed acyl fluorides.
Synthesis of Acyl Fluorides via DAST-Mediated Fluorinative C-C Bond Cleavage of Activated Ketones
Kim, Danhee,Lim, Hee Nam
, p. 7465 - 7469 (2020/10/09)
A new protocol for preparation of acyl fluorides was developed by recognizing activated ketones as starting materials. The method provides a different scope compared with previously reported methods that employ carboxylic acids as substrates. A working hypothesis of pull-and-push-driven fluorinative C-C bond cleavage was successfully demonstrated by the simple addition of diethylaminosulfur trifluoride (DAST) derivatives to α-oximinoketones. The designed reaction system led to a highly efficient and chemoselective reaction. The wide availability of the ketones allowed for a range of synthetically useful aryloyl and aliphatic acyl fluorides including those containing chiral skeletons. The method is mild, fast, scalable, and potentially one-pot operative.
Elemental fluorine. Part 21. (1) direct fluorination of benzaldehyde derivatives
Chambers, Richard D.,Sandford, Graham,Trmcic, Jelena,Okazoe, Takashi
, p. 339 - 344 (2013/01/03)
Direct fluorination of a range of benzaldehyde derivatives gives mixtures of fluorobenzaldehyde and benzoyl fluoride products in ratios that depend upon the nature of the ring substituent Electron-withdrawing substituents give predominantly benzoyl fluoride derivatives, whereas electron-donating substituents lead to fluoroarene systems. Separation of ring-fluorinated products can be easily accomplished by esterification of the benzoyl fluoride side products. Scale-up of these processes to provide significant quantities of appropriate fluorobenzaldehyde systems has also been achieved using continuous flow techniques.
Reactions of alcohols with cesium fluoroxysulfate
Stavber, Stojan,Kosir, Iztok,Zupan, Marko
, p. 4916 - 4920 (2007/10/03)
The reactions of alcohols with cesium fluoroxysulfate (CsSO4F) in MeCN suspension were studied, and the role of the structure of the alcohol and the reaction conditions on the course of reaction was determined. Secondary benzyl alcohols bearing a nonactivating aromatic ring were selectively oxidized to the corresponding ketones, while the CsSO4F-mediated reaction of phenyl-1-naphthylmethanol resulted in the formation of 1-fluoronaphthalene and benzaldehyde. Cyclic and noncyclic secondary alcohols were readily converted to ketones, as well as 1-hydroxybenzecyclanes to benzocyclanones- 1, without any further fluorination or oxidation under the reaction conditions. On the other hand, reactions of primary alcohols with CsSO4F resulted in the formation of acid fluorides derived from further fluorination of aldehydes. Another type of transformation was observed in the case of alcohols bearing a benzyl functional group attached geminal to a hydroxy group, where decarbanylation of reactive intermediates resulting in the formation of benzyl fluoride derivatives became the main process. 2- Phenylethanol was so converted to benzyl fluoride and phenylacetyl fluoride in a 3:1 relative ratio, while 2-phenyl-1-propanol was selectively transformed to 1-phenyl-1-fluoroethane. The presence of the radical inhibitor nitrobenzene in the reaction mixture considerably inhibited conversion of the starting material. The same effect was observed by lowering the solvent polarity. Hammett correlation analysis of the effect of substituents on the reaction rates of oxidation of a set of substituted 1-phenyl-1-ethanols to acetophenones gave the reaction constant p+ = -0.32, while analysis of analogous data for the transformations of benzyl alcohols to benzoyl fluorides gave the value of -0.54. A mechanism including radical intermediates was proposed for the transformation of alcohols by CsSO4F.
Reactions of Aldehydes with Cesium Fluoroxysulfate
Stavber, Stojan,Planinsek, Zdenka,Zupan, Marko
, p. 5334 - 5337 (2007/10/02)
Various aromatic and aliphatic aldehydes reacted at 35-40 deg C in CH3CN with CsSo4F giving acid fluorides in a good yield.In some cases formation of fluorohydrocarbons was also observed.Hammett correlation analysis of the transformation of various substituted benzaldehydes (p-OCH3, p-CH3, p-F, p-CF3, m-NO2) gave the reaction constant ρ+ = -0.38.Solvent polarity strongly influenced the conversion of aldehydes into acid fluorides, being in acetonitrile almost quantitative and completely halted in CH2Cl2, n-hexane, or tetrahydrofuran.The presence of nitrobenzene, often used as a radical scavenger, considerably reduced the acid fluoride formation.Based on experimental observations was concluded that the main intermediates involved in the conversion of aldehydes into acid fluorides with CsSO4F must be of a radical nature.
Die Reacktionen von Bis(perfluoralkyl)cadmium-Komplexen mit Arylcarbonsaeurechloriden: Synthese von Aryl(perfluoralkyl)ketonen, (Perfluoralkyl-dihydropyridin)arylcarbonsaeureamiden, α,α-Bis(trifluormethyl)benzylalkoholen und Benzoesaeure-α,α-bis(trifluormethyl)benzylestern
Naumann, Dieter,Finke, Martina,Lange, Horst,Dukat, Wolfgang,Tyrra, Wieland
, p. 215 - 237 (2007/10/02)
Perfluoroalkylcadmium complexes react with aroyl halides in the presence of strong bases such as pyridine to give the corresponding ketones ArCORf (which can be isolated in 5-51percent yield) and (perfluoroalkyldihydropyridine)aroylamides.The pure substances are obtained by chromatography.Aroyl fluorides and α,α-bis(trifluoromethyl)benzyl alcohols and benzoic acid-α,α-bis(trifluoromethyl)benzyl esters can be isolated as by-products.The dependency of the products formed on the kind of bases used as well as the reaction mechanisms are described.All products were identified by their 19F, 1H, 13C NMR, mass and IR spectra, and by elemental analysis.
MILD CONVERSION OF PRIMARY ALCOHOLS AND ALDEHYDES TO ACID FLUORIDES WITH CAESIUM FLUOROXYSULPHATE
Stavber, Stojan,Planinsek, Zdenka,Zupan, Marko
, p. 6095 - 6096 (2007/10/02)
Caesium fluoroxysulphate in acetonitrile medium at 35 deg C converts primary alcohols and alkyl, as well as aryl aldehydes, to acid fluorides in high yield.
The Relationship between 19F Substituent Chemical Shifts and Electron Densities: meta- and para-Substituted Benzoyl Fluorides
Brownlee, Robert T. C.,Craik, David J.
, p. 186 - 191 (2007/10/02)
The 19F substituent chemical shifts (SCS) of meta- and para-benzoyl fluorides are found to correlate well with substituent parameters using the dual substituent parameter (DSP) equation, indicating that they reflect electronic perturbations induced by the substituent.The direction of the SCS values is such that donating substituents cause upfield shifts whilst acceptors cause downfield shifts.STO-3G calculations indicate that substituents induce only very small changes in ?-electron density about the fluorine atom, but that these changes correlate reasonably well with the observed SCS values.For the para series, the slope of the relationship between Δq?F and 19F SCS is 5000 ppm/electron, indicating the great sensitivity of the fluorine atom to small changes in electron density.
