Perfluoroalkanesulfonate Esters as Alkylating Agents

The first example of linear peptides containing a N-trifluoroethylated backbone amide linkage and the surprising solution dynamics observed by 19F NMR

“…Based on Dickey's research [12], trifluoroethylation of anilines with 2-chloro-1,1,1-trifluoroethane by autoclave reactions, and Hansen's work [13], trifluoroethylation of diethylamine with trifluoroethyl trifluoromethanesulfonate (triflate), Steinman et al [2] prepared and used triclate to obtain the secondary Ntrifluoroethylated anilines and aminobenzophenones. These were then coupled directly with bromoacetyl bromide and phthalimidoacetyl chloride to form desired tertiary amide functionalities.…”

Electrophilic polyfluoroalkylating agents based on sulfonate esters

“…In case of triflates, the situation is much clearer. Triflates are powerful fluoroalkylating agents (around 10,000 times more reactive than the corresponding tosylates) [13], whose reactivity does not decrease with perfluoroalkyl chain length increase [12]. Triflates are the most interesting group of activated polyfluoroalcohol derivatives due to high reactivity [12].…”

“…Preparation of polyfluoroalkyl tosylates. [12,24,53,54] or fluoride [13,55,56] of the trifluoromethanesulfonic acid and polyfluorinated alcohol in the presence of triethylamine are used. The second method utilizes triflic anhydride [57][58][59] in the presence of pyridine.…”

5H-3-oxa-Octafluoropentanesulfonyl fluoride: a novel and efficient condensing agent for esterification, amidation and anhydridization

“…On the basis of the excellent leaving ability of poly(per)fluorosulfonate anion (in comparison with p-toluenesulfonate anion) 6 and the ease of reaction of poly(per)fluoroalkanesulfonyl fluoride with alcohol in the presence of a base, we have studied the reaction of HCF 2 CF 2 OCF 2 CF 2 SO 2 F (an easily available compound in our hand) with threo-diol and hydrogen peroxide (H 2 O 2 ), respectively, in the presence of an organic or inorganic base, resulting in the smooth formation of enantiopure cis-epoxide and in situ generation of highly efficient oxidant polyfluoroalkanesulfonic peracid. 5o,p With these findings in hand and as a continuation of our project of poly(per)fluoroalkanesulfonyl fluoride-mediated reactions and their application in synthetic organic chemistry, we envisaged that the reaction of HCF 2 CF 2 OCF 2 CF 2 SO 2 F with carboxylate anion would produce the unstable mixed anhydride (intermediate A in Scheme 1) which would be easily attacked by a nucleophile such as an alcohol, an amine or a carboxylic acid anion, resulting in the formation of an ester, amide or anhydride (Scheme 1).…”