Synthesis and Characterization of Tetramethylammonium Trifluorosulfate

Abstract

[Me(4) N](+) [SO(2) F(3) ](-) , the first example of a [SO(2) F(3) ](-) salt, has been prepared from Me(4) NF and SO(2) F(2) . The colorless, microcrystalline solid was characterized by its infrared and Raman spectra. The trigonal bipyramidal structure of C(2v) symmetry of the [SO(2) F(3) ](-) anion is predicted by ab initio calculations. Two oxygen atoms with d(SO)=143.2 pm and one fluorine atom with d(SF)=157.9 pm occupy the equatorial plane. The two fluorine atoms in the axial position with d(SF)=168.5 pm are repulsed by the two oxygen atoms forming a bent axis with ∡(F(ax) SF(ax) )=165.2°.

Room Temperature Deoxyfluorination of Benzaldehydes and α-Ketoesters with Sulfuryl Fluoride and Tetramethylammonium Fluoride

“…In combination with tetramethylammonium fluoride (Me 4 NF), SO 2 F 2 effectively converts electronically diverse phenols to the corresponding aryl fluorides under mild conditions . We hypothesized that the inexpensive and thermally stable combination of SO 2 F 2 /Me 4 NF should also enable other deoxyfluorination reactions, and we initially targeted the deoxyfluorination of (hetero)­aromatic aldehydes. This transformation is known with other deoxyfluorinating reagents, , but it has been less extensively studied than analogous alcohol deoxyfluorination reactions.…”

Nucleophilic Deoxyfluorination of Phenols via Aryl Fluorosulfonate Intermediates

“…To gain preliminary insights into the mechanism of this transformation, we conducted ab initio calculations on the reaction of 1-OFs with fluoride (F – ) . As shown in Figure , these calculations reveal that the binding of fluoride to sulfur to form the pentacoordinate intermediate 1-A is enthalpically favorable (Δ H bind = −4.1 kcal/mol for 1-OFs → 1-A ) . The conversion of 1-A to the transition state 1-TS then proceeds with an activation enthalpy (Δ H ‡ ) of 13.2 kcal/mol, consistent with the fast rate measured experimentally.…”

Tetramethylammonium Fluoride: Fundamental Properties and Applications in C-F Bond-Forming Reactions and as a Base

“…Furthermore, monitoring the reaction of aryl fluorosulfonate substrate 221 with TMAF, via 19 F NMR spectroscopy, indicated possible equilibration with the tetramethylammonium salt of the pentacoordinate sulfur intermediate 251 (occurrence of broad resonance in the 19 F NMR spectrum), an observation in line with the detection of analogous pentacoordinate sulfur species after the treatment of sulfuryl fluoride with TMAF [141]. More importantly, careful analysis of that 19 Independent syntheses of these postulated intermediates allowed to corroborate the feasibility of the individual steps leading to the formation of bis-sulfate species 255 (Step iii-v, Scheme 15b) and the reverse reactions from 255 to the fluorinated end-product 252.…”