Process for the preparation of haloalkylalkoxysilanes and haloalkylhalosilanes
View Patent ↗This invention involves a process for the preparation of haloalkylalkoxysilanes and haloalkylhalosilancs. The process comprises reacting an alkoxyhydridosilane or a halohydridosilanc silane with an alkenylhalide compound in the presence of a catalytic amount of an iridium containing catalyst. When a halohydridosilane is the silane reactant. The resulting haloalkylhalosilane may be alkoxylated by reaction with a C 1 -C 6 , alcohol. In another aspect of the invention, the reacting is conducted under a reduced oxygen atmosphere to improve the catalyst activity and the yield of the resulting haloalkylhalosilane or haloalkylalkox vsi lane.
1. A process for preparing a haloalkylalkoxysilane, the process comprising:
reacting a silane of formula (II),
wherein each R 1 and R 3 are independently alkyl groups having from 1 to 6 carbon atoms and n has a value of 0, 1 or 2, with an alkenylhalide compound of formula (III),
wherein R 2 is hydrogen or an alkyl group having from 1 to 6 carbon atoms; X is chloro, fluoro, bromo, or iodo; and z is an integer from 1 to 5, in the presence of a catalytic amount of and iridium containing catalyst having formula (V):
wherein Q is selected from 1,3-butadiene, 1,3-hexadiene, 1,3-cyclohexadiene, 1,3-cyclooctadiene, 1,5-cyclooctadiene and norbornadiene; R 4 is independently hydrocarbyl, halohydrocabyl, cyanoalkyl, alkoxy, cyanoalkoxy, amino, or hydrocarbyl-substituted amino; R 5 is independently hydrogen, hydrocarbyl, halohydrocarbyl, or acyl; and R 6 is independently hydrocarbyl, halohydrocarbyl, or cyanoalkyl, wherein the reacting is conducted under an atmosphere containing <5% (v/v) oxygen.
2. The process of claim 1 wherein the haloalkylalkoxysilane produced comprises a compound of formula (I)
wherein R 1 , R 2 , R 3 , X, n, and z are as defined in claim 1 .
3. The process of claim 1 wherein R 3 is independently methyl, ethyl, propyl, isopropyl or butyl.
4. The process of claim 1 wherein R 1 is independently methyl, ethyl, propyl, isopropyl, or butyl.
5. The process of claim 1 wherein R 1 is independently methyl or ethyl, n equals 0, X is chloro and R 2 is H.
6. The process of claim 1 wherein R 3 is methyl, R 1 is independently ethyl or methyl, n equals 1, X is chloro and R 2 is H.
7. The process of claim 1 wherein R 3 is methyl, R 1 is independently ethyl or methyl, n equals 2, X is chloro, and R 8 is H.
8. The process of claim 1 wherein the temperature is from 20° C. to 200° C.
9. The process of claim 1 wherein the silane or the alkenylhalide is a limiting reagent and the iridium catalyst is at 5 to 900 mole ppm of iridium based upon the limiting reagent.
10. A process for the preparation of a haloalkylhalosilane, the process comprising:
reacting a silane of formula (VI),
wherein R 3 is an alkyl group having from 1 to 6 carbon atoms; X is chloro, bromo, fluoro, or iodo; and n has a value of 0, 1, or 2, with an alkenylhalide compound of formula (III),
wherein R 2 is hydrogen or an alkyl group having from 1 to 6 carbon atoms; z is an integer from 1 to 5; and X is as defined above, in the presence of a catalytic amount of and iridium containing catalyst of formula (V),
wherein Q is independently 1,3-butadiene, 1,3-hexadiene, 1,3-cyclohexadiene, 1,3-cyclooctadiene, 1,5-cyclooctadiene and norbornadiene; R 4 is independently hydrocarbyl, halohydrocabyl, cyanoalkyl, alkoxy, cyanoalkoxy, amino, or hydrocarbyl-substituted amino; R 5 is independently hydrogen, hydrocarbyl, halohydrocarbyl, or acyl; and R 6 is independently hydrocarbyl, halohydrocarbyl, or cyanoalkyl, and wherein the reacting is conducted under an atmosphere having an oxygen content below 5% (v/v).
11. The process of claim 10 wherein the haloalkylhalosilane produced comprises a compound of formula (IX),
wherein R 2 , R 3 , n, and z are as defined in claim 10 and each X is independently a chloro, bromo, fluoro, or iodo group.
12. The process of claim 11 further comprising reacting the haloalkylhalosilane produced with an alcohol containing 1 to 6 carbon atoms.
13. A process for increasing the activity of an iridium hydrosilation catalyst comprising reducing the oxygen content of a reaction atmosphere of a hydrosilation reaction mixture comprising a hydrosilation catalyst according to formula (V)
wherein Q is independently 1,3-butadiene, 1,3-hexadiene, 1,3-cyclohexadiene, 1,3-cyclooctadiene, 1,5-cyclooctadiene or norbornadiene; R 4 is independently hydrocarbyl, halohydrocabyl, cyanoalkyl, alkoxy, cyanoalkoxy, amino, or hydrocarbyl-substituted amino; R 5 is independently hydrogen, hydrocarbyl, halohydrocarbyl, or acyl; and R 6 is independently hydrocarbyl, halohydrocarbyl, or cyanoalkyl, to an oxygen content below 5% (v/v).