%0 Journal Article
%A Raghavanpillai, Anilkumar
%A Burton, Donald J.
%D 2004
%T 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
%U https://acs.figshare.com/articles/journal_contribution/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/3320692
%R 10.1021/jo049179c.s005
%2 https://ndownloader.figshare.com/files/5159479
%K trifluoroethenylzinc reagent
%K THF
%K CF 3 CHF
%K room Temperature Preparation
%K metalation
%K HFC
%K medium
%K TMEDA
%K Trifluoroethenylzinc
%X Trifluoroethenylzinc reagent [CF2CFZnX] was generated from the readily available halocarbon
HFC-134a by an in situ metalation−transmetalation procedure at temperatures near to room
temperature (15−20 °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 °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 (CF3CHF-) 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.
%I ACS Publications