TMSCF₃ as a Convenient Source of CF₂=CF₂ for Pentafluoroethylation, (Aryloxy)tetrafluoroethylation, and Tetrafluoroethylation

Abstract

A new method for the on-site preparation of tetrafluoroethylene (TFE) and a procedure for its efficient use in pentafluoroethylation by fluoride addition were developed by using a simple two-chamber system. The on-site preparation of TFE was accomplished by dimerization of difluorocarbene derived from (trifluoromethyl)trimethylsilane (TMSCF ) under mild conditions. Other fluoroalkylation reactions, such as (aryloxy)tetrafluoroethylation and tetrafluoroethylation processes, were also achieved using a similar approach. This work not only demonstrates a convenient and safe approach for the generation and use of TFE in academic laboratories, but also provides a new strategy for pentafluoroethylation.

Controllable double CF2-insertion into sp2 C–Cu bond using TMSCF3: a facile access to tetrafluoroethylene-bridged structures

“…Current methods for the syntheses of tetrauoroethylenebridged structures are mainly based on (1) deoxouorination of 1,2-dicarbonyl compounds with SF 4 and DeoxoFluor; [9][10][11] (2) uorination of C-C triple bonds using F 2 ; [12][13][14] (3) 1,2-difunctionalization of tetrauoroethylene (TFE); [15][16][17][18][19][20][21][22][23] (4) diuoromethylene insertion using CF 2 Br 2 as the CF 2 source; 24,25 and (5) using RCF 2 CF 2 Br as the build block. 5 However, these methods suffer from several drawbacks such as (1) using toxic, highly reactive or hazardous reagents; (2) low functional group tolerance and/or (3) using explosive gaseous reagents or ozonedepleting substances (ODS).…”

Advances in the Synthesis and Application of Tetrafluoroethylene‐ and 1,1,2,2‐Tetrafluoroethyl‐Containing Compounds

“…By changing the solvent to DMF, the authors even managed to perform the one‐pot synthesis without the need of the phenanthroline ligand. Oxycupration was at the same time also reported by the group of Hu . Using tetrafluoroethylene generated from the Ruppert–Prakash reagent (Chapter 2.2, Scheme ), they formed the copper(I)‐phenanthroline complex and used it in a reaction with 1‐iodo‐4‐nitrobenzene (Scheme ).…”

“…Nitrogen heterocycles react with TFE in the sense of nucleophilic addition (Table ) , , . The corresponding products 16 are more stable to hydrolysis because of conjugation of the nitrogen electron pair with the heterocyclic ring …”

“…Even though the reaction is usually performed under elevated temperature and pressure, Sokolenko and co‐workers described the product formation even at ambient pressure (Table , entries 7 and 8) , . In polyols, all hydroxyls participate in the TFE addition (Table , entries 10–13) , . Products from entries 7 and 8 serve as precursors for the synthesis of various heterocyclic compounds with the 1,1,2,2‐tetrafluoroethoxy group attached directly to the heterocycle ring , , …”

Recent Advances in Transition Metal‐Catalyzed Functionalization of gem‐Difluoroalkenes

“…In the presence of CsF, a Cu I -based catalyst and iodoarenes, tetrafluoroethylene (227) was converted to various pentafluoroethylated products (229) in a simple two-chamber system (Scheme 65). [53] In this reaction, trifluoromethyl trimethylsilane (TMSCF 3 ) served as a source for the in situ generation of tetrafluoroethylene. Difluorocarbene, generated from TMSCF 3 and a catalytic amount of NaI, dimerized to produce 1,1,2,2-tetrafluoroethylene.…”