Transformations of Organic Molecules with F-TEDA-BF4 in Ionic Liquid Media

Abstract

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.

SelectFluor and Its Analogs Fluorination for Preparing Alkenyl Fluorides

“…In this reaction, the bis-benzylic carbocation was sufficiently stable to disfavor nucleophilic attack, which in turn permitted elimination of H + to generate the fluoroalkene. Similar results were also obtained in an ionic liquid solvent, instead of acetonitrile (Scheme 2a) [15]. Later, this strategy was extended to tetraline derivatives (Scheme 2b) [4].…”

Monofluorination of Organic Compounds: 10 Years of Innovation

“…The same group later disclosed the influence of the ionic liquid used to perform the Selectfluor-mediated electrophilic fluorination of phenols. The use of [bmim]­[BF 4 ] (1-butyl-3-methylimidazolium tetrafluoroborate) allowed the quantitative fluorination of 3,4,5-trimethylphenol to the fluorinated dienone 143 (Scheme ) . On the other hand, the reaction in [bmim]­[PF 6 ] (1-butyl-3-methylimidazolium hexafluorophosphate) did not proceed at room temperature, while polymeric material was recovered upon running it at elevated temperatures.…”

“…As such, reacting Selectfluor or Accufluor on phenols (R 2 = H) mostly produced 161 in acetonitrile or methanol, with better selectivities and yields in the latter . The conversions and yields could not be improved by using ionic liquids instead . When employing another fluorinating agent, cesium fluoroxysulfate (CsSO 4 F) in CH 3 CN, yields of the desired product 161 were increased, sometimes with exquisite selectivities .…”

Multi‐Ferrocenyl Aryl Ethers – Applying Nucleophilic Aromatic Substitution Reactions to Aryl Fluorides

“…Compounds 5c and 5d were isolated in a yield of 2 % as a 2:1 mixture of asym ‐ 5c and sym ‐ 5d . Compound 5c , with its 1,4,5‐substituted FcO moieties, is the first example of this type, but also molecules possessing a 1,3,5‐substitution pattern, as observed in 5d , have rarely been reported . After appropriate work‐up, both isomers could be identified by 1 H and 19 F NMR spectroscopy (see below), but could not be separated, for example, by using chromatographic methods.…”