Process for preparing polyfluoroalkylithium compounds

1. A process for preparing polyfluoroalkyllithium compounds comprising deprotonating polyfluoroalkyl compounds of the formula (I)

HCF 2 R 1   (I)

wherein

R 1 is fluorine, (CF 2 ) n CF 3 , (CF 2 ) n R 2 ,

n is an Integer from 0 to 17, and

R 2 is tri(C 1 -C 6 -alkyl)silyl, triphenylsilyl, cyclic alkyl having from 3 to 8 carbon atoms, straight-chain or branched alkyl having from 1 to 24 carbon atoms, aryl having from 6 to 10 carbon atoms, arylalkyl having from 7 to 18 carbon atoms, straight-chain or branched alkenyl having from 2 to 12 carbon atoms, straight-chain or branched alkoxy having from 1 to 12 carbon atoms, aryloxy having from 6 to 10 carbon atoms, heteroaryl having from 4 to 9 carbon atoms, heteroarylalkyl having from 5 to 17 carbon atoms, heteroaryloxy having from 4 to 9 carbon atoms, where (i) the heteroaryl radicals each contain up to 2 hetero atoms selected from the group consisting of oxygen, sulfur, and nitrogen, (ii) the alkyl radicals are optionally substituted further by fluorine, di(C 1 -C 6 -alkyl)amino, or alkylthio or alkyloxy each having from 1 to 12 carbon atoms, and (iii) the aromatic substituents optionally bear 1, 2, or 3 further substituents selected independently from the group consisting of fluorine, cyclic alkyl having from 3 to 6 carbon atoms, straight-chain or branched alkyl having from 1 to 12 carbon atoms, straight-chain or branched alkoxy or alkylthio each having from 1 to 12 carbon atoms, straight-chain or branched alkenyl having from 2 to 12 carbon atoms, di(C 1 -C 6 -alkyl)amino, or N—(C 5 -C 12 )-azacycloalkyl;

wherein the deprotonation is carried out with a lithium base.

2. The process according to claim 1 wherein the polyfluoroalkyl compounds are compounds of the formula (I)

HCF 2 R 1   (I)

wherein

R 1 is fluorine, (CF 2 ) n CF 3 , (CF 2 ) n R 2 ,

n is an integer from 0 to 17, and

R 2 is phenyloxy or phenoxy substituted by 1, 2, or 3 alkyloxy groups having from 1 to 6 carbon atoms.

3. The process according to claim 1 wherein the lithium base is lithium bis(trimethylsilyl)amide, lithium diisopropylamide, phenyllithium, or a compound of the formula (II)

LiCR 3 R 4 R 5   (II)

where, independently of one another,

R 3 is hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, or n-heptyl,

R 4 is hydrogen or methyl, and

R 5 is hydrogen or methyl, or

CR 4 R 5 R 6 is cyclopentyl or cyclohexyl.

4. The process according to claim 2 wherein the lithium base is n-butyllithium, sec-butyllithium, tert-butyllithium, or phenyllithium.

5. The process according to claim 1 wherein the lithium base is used as a solution.

6. The process according to claim 1 wherein deprotonation is carried out at from −110 to −50° C.

7. The process according to claim 1 wherein deprotonation is carried out in the presence of one or more complexing compounds.

8. The process according to claim 7 wherein deprotonation is carried out in the presence of a crown ether, a cryptand, a podand, a polyether, or an amine or a combination thereof.

9. The process according to claim 1 wherein deprotonation is carried out in the presence of potassium tert-butoxide or sodium tert-butoxide.

10. A process for preparing a polyfluoroalkyl compound comprising

(a) deprotonating a polyfluoroalkyl compound according to claim 1 , and

(b) reacting the deprotonated polyfluoroalkyl compound with an electrophile.