New partially fluorinated epoxides by oxidation of olefins with sodium hypohalites under phase transfer catalysis
作者:Viacheslav A. Petrov、Will J. Marshall、Carl.G. Krespan、Victor F. Cherstkov、Era A. Avetisian
DOI:10.1016/j.jfluchem.2003.11.002
日期:2004.1
Partially fluorinated epoxides can be readily prepared by oxidation of the corresponding olefins by NaOCl (or NaOBr) under phase transfer catalysis (PTC) conditions. Oxidation of CH2C(CF3)2 at 0–5 °C leads to the formation of 2,2-bis(trifluoromethyl)oxirane in 65–75% yield. (CF3)2CCHCH2X (X=Cl or Br) were converted into the corresponding epoxides in 24–31% yield by the action of NaOCl and NaOBr,
A two-step synthesis of 1-bromo-4,4,4-trifluoro-3-(trifluoromethyl)but-2-ene in 35% overall yield is reported starting from commercially available hexafluoroacetone. The electrophilic reactivity of this new compound towards various nucleophilic reagents has been studied. Substitution products or ones arising from allylic rearrangement are obtained depending on the nature of the nucleophile.
Direct synthesis of polyfluorinated allyl halides from fluoroolefins and AlX3 (X = Cl, Br)
作者:Viacheslav A. Petrov
DOI:10.1016/s0022-1139(02)00165-3
日期:2002.9
Reaction of (perfluoro-i-propyl)ethylene with aluminum chloride or bromide results in formation of (CF3)2CCHCH2X (X=Cl or Br) in 50–65%yield. Both compounds were converted into corresponding iodide under conditions of Finkelstein reaction. Olefins (CF3)2CCHCH2X readily undergo isomerization into (CF3)2CHCHCHX under action of triethylamine.