A highly efficient room temperature non-organometallic route for the synthesis of α,β,β-trifluorostyrenes by dehydrohalogenation

The functionalization of fluoroelastomers: approaches, properties, and applications

This review seeks to give an overview of different approaches to prepare functional fluoroelastomers for modern industries.

Diversity-oriented approach to CF3CHF-, CF3CFBr-, CF3CF2-, (CF3)2CH-, and CF3(SCF3)CH-substituted arenes from 1-(diazo-2,2,2-trifluoroethyl)arenes

Arenes substituted with perfluoroalkyl groups are attractive targets for drug and agrochemical development. Exploiting the carbenic character of donor/acceptor diazo compounds, a diversity-oriented synthesis of perfluoroalkylated arenes, for late stage fluorofunctionalization, is described. The reaction of 1-(diazo-2,2,2-trifluoroethyl)arenes with HF, F/Br, F2, CF3H, and CF3SH sources give direct access to a variety of perfluoroalkyl-substituted arenes presenting with incremental fluorine content. The value of this approach is also demonstrated for radiochemistry and positron emission tomography with the [(18)F]-labeling of CF3CHF-, CF3CBrF-, and CF3CF2-arenes from [(18)F]fluoride.

Room Temperature Preparation of Trifluoroethenylzinc Reagent by Metalation of the Readily Available Halocarbon HFC-134a and an Efficient, Economically Viable Synthesis of 1,2,2-Trifluorostyrenes

Trifluoroethenylzinc reagent [CF(2)=CFZnX] was generated from the readily available halocarbon HFC-134a by an in situ metalation-transmetalation procedure at temperatures near to room temperature (15-20 degrees C). By systematic standardization of the metalation experiments by manipulation of solvent, cosolvent, temperature, zinc salt, and the base, the trifluoroethenylzinc reagent was produced in 73% yield at 20 degrees C in THF medium. The palladium-catalyzed cross-coupling reaction of the trifluoroethenylzinc reagent with various aryl iodides was carried out under mild reaction conditions to produce 1,2,2-trifluorostyrenes in 59-86% isolated yields. The stability of the intermediate trifluoroethenyllithium reagent was compared at different temperatures and solvent systems. Experimental evidence for the mono-anion from HFC-134a (CF(3)CHF(-)) was obtained by the trapping of the mono-anion with zinc halide in THF/TMEDA medium. The structure and complexation of both the mono- and bis-trifluoroethenylzinc reagents with TMEDA and other ligands are discussed.