How Trimethyl(trifluoromethyl)silane Reacts with Itself in the Presence of Naked Fluoride—A One‐Pot Synthesis of Bis([15]crown‐5)cesium 1,1,1,3,5,5,5‐Heptafluoro‐2,4‐bis(trifluoromethyl)pentenide

Abstract

Reactions of trimethyl(trifluoromethyl)silane in the presence of "naked" fluoride proceed up to a temperature of +5 degrees C mainly with formation of [Me3Si(CF3)2]-. A further rise of temperature up to about 20 degrees C gives evidence for the formation of a salt with the 1,1,1,2,3,6,6,6-octafluoro-2,4,4,5,5-pentakis(trifluoromethyl)hexan-3-ide anion. This intermediate decomposes at room temperature into the 1,1,1,3,5,5,5-heptafluoro-2,4-bis(trifluoromethyl)pentenide anion. The bis([15]crown-5)cesium salt, [Cs([15]crown-5)2][(CF3)2CCFC(CF3)2] has been characterized unambiguously as the stable final product of this reaction sequence. Thermal decomposition of this salt opens a convenient nontoxic route to obtain 1,1,3,3-tetrakis(trifluoromethyl)allene, (F3C)2C=C=C(CF3)2.

Stable gem-trifluoromethyl anionic σ-complexes based on 1,3,5-tris(sulfonyl)benzene derivatives and their transformations

“…In order to increase a conversion degree of 1 the silicate [Cs( [15]crown-5) 2 ][Me 3 Si(CF 3 ) 2 ] [14] was synthesized that is stable in the solution up to À5 8C. In the reaction of 1 with this silicate in DME in temperature range from À50 8C to À15 8C, 19 F NMR data of the anionic s-complexes [4][5][6]8,10,[14][15][16][17][18][19], (d/ppm, J/Hz). The numbering of the C-atoms see in Scheme 6. the conversion of the starting compound increases from 60 to 95% and the total yield of the anionic complexes 4 and 5 with the same ratio (4:1) has been brought to 65%.…”

“…It should be noted that SO 2 OCH 2 CF 3 group is a rather electron withdrawing substituent (s p -SO 2 OCH 2 CF 3 = 0.88 [11]). Furthermore, in contrast to the compounds containing nonfluorinated alkoxysulfonyl groups, which are strong alkylating agents, the derivatives including SO 2 OCH 2 CF 3 groups are stable Table 2 13 C NMR data of the anionic s-complexes 6,8,10,[14][15][16], (d/ppm, J/Hz). The numbering of the C-atoms see in Scheme 6.…”

Hydrolytic Decomposition of Tetramethylammonium Bis(trifluoromethyl)aurate(I), [NMe4][Au(CF3)2]: A Route for the Synthesis of Gold Nanoparticles in Aqueous Medium

“…Quartets and septets in the 19 F NMR spectra Ϫ although of very low intensity Ϫ indicated tris(trifluoromethyl)gold(III) species of so far unknown composition. [24] The 13 An unexpected aurate(I), 1,1,1,4,5,5,5-heptafluoro-2,4-bis(trifluoromethyl)pent-2-ene-3-(trifluoromethyl)aurate(I) (Scheme 2), was identified with the help of correlated spectroscopy ( 19 F, 19 F and 19 F, 13 C), when a larger excess amount (Ͼ20 %) of Me 3 SiCF 3 was used, thus implying a similar reaction sequence as investigated for the formation of the 1,1,1,4,5,5,5-heptafluoro-2,4-bis(trifluoromethyl)pentide ion [25] in fluoride-mediated reactions of Me 3 SiCF 3 with itself. [28] Within the accessible range, the compound exhibited two irreversible oxidation waves at +0.73 and +1.05 V, which were tentatively assigned to Au I /Au II and Au II /Au III couples, respectively.…”

Palladium‐Catalyzed Decarbonylative Trifluoromethylation of Acid Fluorides

“…This is due to the propensity of the transmetalating “CF 3 anions” to displace these weaker coordinating ligands 4e, 5c, 7. Moreover, several equivalents of fluoride salt additive are generally required to activate the transmetalating agent, such as R 3 SiCF 3 , and even the smallest parts per million quantities of moisture introduced by these salts can cause catalyst decomposition 4e, 8. As such, Buchwald's catalytic Pd 0 /Pd II ‐catalyzed trifluoromethylation of aryl chlorides is a major accomplishment 9.…”