Soluble polymer supports that could be used in thermomorphic and latent
biphasic systems have been prepared and analyzed for their potential application as
supports for facilitated synthesis and catalysis. Phase selective solubilities were
evaluated using polymers tagged with either visible dyes or fluorescent probes.
Heptane/DMF, heptane/90% ethanol-water, heptane/ethyl acetate, heptane/ ethanol and
heptane/tert-butanol solvent mixtures were all studied as examples of thermomorphic or
latent biphasic systems. A range of polymers, including poly-(tert-butylstyrene)
(PTBS), poly(alkylsiloxanes) (PAS), poly(dodecylvinylpyrrolidone) (PDVP),
poly(didodecylvinylpyrrolidone (PDDVP), poly(isobutylene) (PIB), poly(octadecyl
acrylate)s (PODA), and poly(octadecyl methacrylate)s (PODMA), were tested for
hydrophobic phase selective solubility.
The results of these studies were compared to prior work with polar and nonpolar
poly(N-alkylacrylamide)s and polystyrene. Together with this prior work, these results
have indicated that a wide range of polymers and solvent mixtures can be used for the
recycling of soluble polymer-bound catalysts, reagents and sequestrants using either
thermomorphic or latent biphasic separation strategies.Synthetic routes to terminally functionalized polyisobutylene oligomers, useful
as supports in synthesis and catalysis, are also discussed and described. Such
hydrocarbon polymers serve as highly soluble nonpolar analogs of well known
poly(ethylene glycol) supports for synthesis and catalysis with the difference that the
polymers are separated after a reaction by an extraction with alkane solvent.
The synthesis of two polyisobutylene-supported phase transfer catalysts (PTC)
are also described. These PTCs utilize the robust triazole functionality as a key synthetic
step towards the preparation of the catalytic species. N alkylation of a PIB-supported
triazole provides a direct route to the preparation of a PTC. Preparation of a tertiary
phosphoninium salt containing a terminal alkyne allows simple attachment of the PTC to
a PIB-supported azide via a triazole linker using Sharpless' Cu (I) [3 + 2] cycloaddition.
These materials are active in catalyzing solid-liquid PTC and can be easily recycled by
liquid-liquid extraction techniques.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/4312 |
| Date | 30 October 2006 |
| Creators | Sung, Shayna D |
| Contributors | Bergbreiter, David E. |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | 1046061 bytes, electronic, application/pdf, born digital |
Page generated in 0.0019 seconds