Anionic σ-complexes of 1,3,5-tris(fluorosulfonyl)benzene

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%.…”

“…Fluorosulfonyl group is very similar by its electronic properties (s p = 1.01 [9]) to the trifluoromethylsulfonyl substituent (s p = 1.04 [9]), thus it can be supposed that compound 2 is activated enough to form anionic s-complex and recently we have provided experimental evidence for this fact [10]. It is pertinent to remark here that sulfonylfluoride 2 presents interesting possibilities in the sense that it has two potential electrophilic centers for reaction with nucleophile -SO 2 F group and a free position of the aromatic ring.…”

“…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.…”

“…Recently we have developed a suitable method for preparation of 1,3,5-tris(fluorosulfonyl)benzene and its derivatives [7,8]. It is pertinent to remark here that to best of our knowledge in the literature there are no examples of organic molecules containing both CF 3 and above mentioned groups.…”

The Ambident Reactivity of 2,4,6‐Tris(trifluoromethanesulfonyl)anisole in Methanol: Using the SO2CF3 Group as a Tool to Reach the Superelectrophilic Dimension in σ‐Complexation Processes

“…The last decade has witnessed considerable interest in studies of highly electron-deficient aromatic and heteroaromatic compounds, termed herein as Meisenheimer electrophiles, [1][2][3][4][5][6][7][8][9][10][11] which show increased reactivity with nucleophiles in the formation of s-bonded anionic complexes. The high susceptibility of 4,6-dinitrobenzofuroxan (DNBF, 1 a) to undergo s complexation in the absence of any added base in water or methanol is a nice illustration of this behaviour.…”