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.
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,
This invention relates to cleaning compositions comprising unsaturated fluorinated hydrocarbons. The invention further relates to use of said cleaning compositions in methods to clean, degrease, deflux, dewater, and deposit fluorolubricant. The invention further relates to novel unsaturated fluorinated hydrocarbons and their use as cleaning compositions and in the methods listed above.
Disclosed is a method for removing residue from a surface comprising: contacting the surface with a composition comprising at least one unsaturated fluorinated hydrocarbon selected from the group consisting of compounds having the formula E- or Z—R
1
CH═CHR
2
, wherein R
1
and R
2
are, independently, C
1
to C
6
perfluoroalkyl groups, or C
1
to C
6
hydrofluoroalkyl groups, and recovering the surface from the composition.
Disclosed is a method for removing residue from a surface comprising: contacting the surface with a composition comprising at least one unsaturated fluorinated hydrocarbon selected from the group consisting of compounds having the formula E- or Z—R
1
CH═CHR
2
, wherein R
1
and R
2
are, independently, C
1
to C
6
perfluoroalkyl groups, or C
1
to C
6
hydrofluoroalkyl groups, and recovering the surface from the composition.