Kinetic studies on the hydrosilylation of phenylacetylene with R3SiH (R3 = PhMe2, Ph2Me, Ph3, Et3) using bis(1,2-diphenylphosphinoethane)norbornadiene rhodium(I) hexafluorophosphate as catalyst
✍ Scribed by Jorge Cervantes; Guillermo González-Alatorre; Diane Rohack; Keith H. Pannell
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 71 KB
- Volume
- 14
- Category
- Article
- ISSN
- 0268-2605
No coin nor oath required. For personal study only.
✦ Synopsis
Product distribution and kinetic studies on the hydrosilylation of phenylacetylene by Ph 3 SiH, Ph 2 MeSiH, PhMe 2 SiH and Et 3 SiH were performed using bis-[1,2-diphenylphosphinoethane]norbornadienerhodium(I) hexafluorophosphate, 1, as catalyst. Pre-equilibration of the catalyst with the acetylene produced hydrosilylations, pre-equilibration with the silane did not. The catalyst showed a pronounced selectivity for cis-addition to form b-products, t-PhCH= CHSiR 3 , unlike most hydrosilylation catalysts. The kinetic studies showed a hydrosilylation reaction that is zero order with respect to both acetylene and the silane, with a dependency upon catalyst concentration. The k obs value is directly influenced by the substituents on the silane: k(PhMe 2 SiH) b k (Et 3 SiH b k (Ph 2 MeSiH) b k (Ph 3 SiH). Intercalation of the catalyst in hectorite was not useful, since either no reaction occurred in non-polar solvents, or extraction of the catalyst occurred in polar solvents to produce the same product distributions.