HIGH SELECTIVITY PROCESS TO MAKE DIHYDROFLUOROALKENES
申请人:SWEARINGEN Ekaterina N.
公开号:US20080269532A1
公开(公告)日:2008-10-30
Disclosed is a method for the synthesis of fluorinated alkenes comprising contacting a fluorinated alkyne of the formula R
1
C≡C R
2
, wherein R
1
and R
2
are independently selected from CF
3
, C
2
F
5
, C
3
F
7
, and C
4
F
9
, in a pressure vessel, with a Lindlar catalyst, with substantially one molar equivalent of hydrogen, to make the corresponding cis-alkene of formula R
1
C≡C R
2
with high selectivity, wherein said hydrogen is added in portions over a period of time, so as to produce an initial pressure in the pressure in the vessel of no more than about 100 psi.
A catalytic synthesis of polyfluoroolefins was developed proceeding from polyfluorochlorocarbons with the use of industrially produced nickel-chromium catalyst. Three ways of the catalytic synthesis of fluoroolefins were implemented: the cleavage of vicinal chlorine atoms from polyfluorochlorocarbons, the replacement of vinyl chlorine atoms by hydrogen in fluorochloroolrfins, and the reductive dimerization of polyfluorochlorocarbons containing a trichloromethyl group. The condition of a prolonged operation of the nickel-chromium catalyst was found consisting in the application of quartz for absorption of the hydrogen fluoride formed as a side product.