The Use of Lipophilic Molecules as Solubility Promoters for Catalysis, Synthesis, and Nanoparticle Modification

Abstract

This dissertation describes the use of lipophilic molecules as solubility promoters for the development of homogeneous recyclable catalysts, the facilitation of efficient purification in organic synthesis, and the preparation of highly soluble nanoparticles in nonpolar solvents. Several polyisobutylene (PIB)-bound were used as catalysts. PIB-bound cobalt(II) MPc was synthesized and used as an effective and recyclable catalyst for nitroarene reduction. The result showed that the catalyst was effective and recyclable for at least 10 cycles. The use of a PIB-bound iron(II) MPc for aerobic oxidation of ethyl phenylhydrazinecarboxylate and the use of a PIB-bound chromium(III) MPc for the rearrangement reaction of an epoxide to an aldehyde are also discussed.

Octadecyldimethylchlorosilane was used as a silylation reagent and a purification auxiliary. A procedure using heptane phase selectively soluble octadecyldimethylsilyl groups to facilitate separations and silyl reagent regeneration was developed. Alcohols and alkynes protected by these groups were shown to be phase-selectively soluble in hydrocarbon solvents, allowing these compounds to be purified by a simple liquid/liquid extraction. Applications of using the octadecylsilyl protecting group in a Grignard synthesis and Sonogashira reaction were studied.

Highly heptane-soluble iron-oxide nanoparticles were synthesized using PIB-supported ligands. These PIB-supported ligands were synthesized and grafted to nanoparticles to prepare heptane-soluble PIB-modified magnetic nanoparticles as magnetically susceptible oils. These magnetic oils were dissolved in poly(alpha-olefin)s and molten polyethylene to prepare magnetically susceptible polymeric nanocomposites. Using the magnetic oil to remove heptane from water is also discussed. The work was also extended to explore strategies that can solubilize silica nanoparticles in heptane.