26885-71-2Relevant articles and documents
2,3,3,3-Tetrafluoropropene (HFO-1234yf) as a CF3-Building Block: Synthesis of Enol Ethers and Vinyl Sulfides
Murray, Ben J.,Ball, Ellis D.,Harsanyi, Antal,Sandford, Graham
, p. 7666 - 7672 (2019/12/24)
2,3,3,3-Tetrafluoropropene (HFO-1234yf) is an inexpensive and readily available fluorinated building block, owing to its growing use as a low global warming potential 4th generation refrigerant, but there have so far been few reported uses of this fluoroalkene in organic synthesis. Herein, we report our investigations into nucleophilic substitution reactions of HFO-1234yf with alkoxide and thiolate derivatives. The regiochemistry of these transformations varies with conditions and we propose these reactions proceed through addition–elimination with reversible formation of a carbanion intermediate. The regioselectivity is dictated by hard/soft nucleophile/electrophile control. This is supported by deuterium trapping of the proposed reactive intermediate. The effect of solvent and base choice was examined and the substrate scope for the synthesis of α-trifluoromethyl enol ethers was expanded.
Chemoselective halogenation of 2-hydroperfluoroalkyl aldehydes
Wiebe, Donald A.,Burton, Donald J.
experimental part, p. 4 - 11 (2012/07/13)
2-Hydroaldehydes, RfCH(R)CHO, where Rf = CF 3, C2F5, n-C3F7 and R = CF3, C2F5, n-C3F7, Ph, H, were prepared via acid hydrolysis of the corresponding vinyl ethers, R fC(R) = CHOCH3, which can be readily prepared by reaction of Ph3P+C?HOCH3 with the corresponding ketone. The 2-hydroaldehydes can be chemoselectively converted to the acyl halide, RfCH(R)C(O)X (X = Cl, Br), via free-radical halogenation. The perfluoroalkyl group deactivates the 2-position toward radical abstraction of the 2-hydrogen, and halogenation occurs exclusively at the formyl hydrogen. However, halogenations of the 2-hydroaldehydes in glacial acetic acid chemoselectively gives the 2-haloaldehydes, RfCX(R)CHO, X = Cl, Br. Hydrolysis of the 2-hydroperfluoroacyl halides provides a useful route to 2-hydroperfluoroalkyl branched carboxylic acids, useful ketene precursors. This route avoids the use of toxic fluoroolefins, such as perfluoroisobutylene.
