Process for preparing unsaturated organosilicon compounds

1. A process for preparing unsaturated organosilanes containing organic carbonyloxy groups and having the formula

(R 1 O) 3-n R 2 n Si—X—OC(O)C(R 3 )═CR 3 2   (I),

where

R 1 are identical or different monovalent, substituted or unsubstituted C 1-10 hydrocarbon radicals optionally interrupted by oxygen atoms,

R 2 are identical or different monovalent, SiC-bonded, substituted or unsubstituted C 1-10 hydrocarbon radicals optionally interrupted by oxygen atoms or a sil(oxan)yl radical,

X each are divalent, substituted or unsubstituted C 1-40 hydrocarbon radicals optionally interrupted by oxygen atoms,

R 3 are identical or different and are a hydrogen atom or a monovalent, substituted or unsubstituted C 1-40 hydrocarbon radical optionally interrupted by oxygen atoms, and n is 0, 1, 2 or 3,

comprising reacting haloorganofunctional silicon compounds of the formula

(R 1 O) 3-n R 2 n Si—X—Y  (II),

where Y is a halogen atom,

with a salt of an unsaturated organic carboxylic acid of the formula

M[OC(O)C(R 3 )═CR 3 2 ] o   (III),

where

R 3 is as defined above, M is an alkali metal atom or alkaline earth metal atom and o is 1 or 2 depending on the valence of M,

in the presence of at least one tertiary phosphine of the formula IV

R 4 3 P  (IV)

where

the radicals R 4 are identical or different monovalent C 1-20 hydrocarbon radicals.

2. The process of claim 1 , wherein at least one tertiary phosphine is selected from the group consisting of tributylphosphine, trioctylphosphine, and triphenylphosphine.

3. The process of claim 1 , wherein the molar ratio of the salt of formula (III) to the haloorganofunctional silicon compound of the formula (II) is from 0.5 to 1.5.

4. The process of claim 2 , wherein the molar ratio of the salt of formula (III) to the haloorganofunctional silicon compound of the formula (II) is from 0.5 to 1.5.

5. The process of claim 1 , wherein the process is carried out under an inert gas atmosphere.

6. The process of claim 1 , wherein tertiary phosphines are used in an amount of from 0.5 to 10 percent by weight, based on the amount of the haloorganofunctional silicon compound of the formula (II).

7. The process of claim 1 , wherein the salt of the formula (III) which is used is obtained by reacting an aqueous solution of a metal hydroxide (i) of the formula (VII) M(OH) k , where k is 1 or 2 depending on the valence of M, with an unsaturated organic carboxylic acid (ii) of the formula

HOC(O)C(R 3 )═CR 3 2   (IV),

in the presence of an organic solvent (iii) which forms an azeotrope with water and forms a two-phase system with water in the liquid state, followed by a) removing water by azeotropic distillation, and b) separating from 10 to 100% by weight of the organic solvent by distillation.

8. The process of claim 1 , which is carried out in the presence of an organic solvent.

9. The process of claim 1 , wherein haloorganofunctional silicon compounds of the formula (II) are reacted with a salt of an unsaturated organic carboxylic acid of the formula (III) in the presence of at least one tertiary phosphine, a polar aprotic organic solvent and an inhibitor.

10. The process of claim 1 , wherein haloorganofunctional silicon compounds of the formula (II) are reacted with a salt of an unsaturated organic carboxylic acid of the formula (III) in the presence of at least one tertiary phosphine, a polar aprotic organic solvent and an inhibitor, where the salt of the formula (III) is prepared by reacting an aqueous solution of a metal hydroxide (i) of the formula (VII) with an unsaturated organic carboxylic acid (ii) of the formula (IV) in the presence of an organic solvent (iii) which forms an azeotrope with water and forms a two-phase system with water in the liquid state, followed by a) removing the water by azeotropic distillation and b) separating from 10 to 100% by weight of the organic solvent used by distillation.