Design of polymer architectures for catalysis

Hoyt, Caroline B.

Title:

Design of polymer architectures for catalysis

dc.contributor.advisor	Jones, Christopher W.
dc.contributor.author	Hoyt, Caroline B.
dc.contributor.committeeMember	France, Stefan
dc.contributor.committeeMember	Sadighi, Joseph P.
dc.contributor.committeeMember	Collard, David M.
dc.contributor.committeeMember	Bucknall, David G.
dc.contributor.department	Chemistry and Biochemistry
dc.date.accessioned	2019-01-16T17:20:57Z
dc.date.available	2019-01-16T17:20:57Z
dc.date.created	2017-12
dc.date.issued	2017-11-13
dc.date.submitted	December 2017
dc.date.updated	2019-01-16T17:20:57Z
dc.description.abstract	Polymer structures provide tunable platforms for catalyst design due to the high degree of structural control possible in their synthesis. In this study, several different molecular catalysts have been prepared on polymer supports targeting applications in organic synthesis and fundamental catalysis. An overall goal of this thesis was to demonstrate the benefits of various polymer catalyst architectures in a variety of catalytic reactions including cooperative and cascade catalysis using acid and base sites, acid catalyzed hydroboration reactions, and Pd catalyzed C–H arylation. This thesis is organized into six chapters. The first chapter gives an overview of the use of polymer supported catalysts in organic synthesis, with a special emphasis on the use of polymer supports in organocatalysis. The second chapter explores the application of a linear polymer support in cooperative catalysis of the aldol reaction, which is a system that has been extensively studied on mesoporous silica supports. The new linear polymer catalyst demonstrated comparable reactivity to the mesoporous silica supports, and the importance of monomer unit placement, strength of the acid and base, and the acid-base ratio are demonstrated. The third chapter extends the concepts learned from the second chapter with regard to acid-base cooperative catalysis to polymer-silica hybrid catalysts in which the acid and base sites are confined into separate domains within the catalyst. In this chapter, the acid and base functionalities are incorporated into mesoporous silica and polymer brush domains to yield a polymer brush catalyst that targets a 3-step cascade reaction. The next chapter is a fundamental kinetic and mechanistic study of the hydroboration of various alkynes with pinacolborane utilizing a carboxylic acid polymer catalyst. The study elucidated the kinetic order of the reaction in catalyst and substrates, and a proposed mechanism was supported by a kinetic isotope effect and 11B NMR studies. The linear polymer catalyst was the first example of an organocatalytic polymer catalyst for the hydroboration of functionalized alkynes. Chapter five discusses the utility of a polymer micelle support for the Pd-catalyzed C(sp3) – H monoarylation. Using this micelle support, steric and electronic effects were invoked to direct the C – H monoarylation of an unnatural amino acid with substituted aryl iodides. The support demonstrated high tolerance for substituted aryl iodide coupling partners, while also recycling the support. The use of the polymer micelle was one of the first demonstrations of this support applied to C – H activation, and the support has many tunable properties that can be adjusted in future applications. Lastly, the final chapter outlines possible future directions for these different projects as well as summarizes the fundamental findings from each of these studies. Understanding the fundamental aspects that were tuned for each support and applied to these organocatalytic reactions provides a basis for future improvements on these supports as well as applications in synthetic organic chemistry.
dc.description.degree	Ph.D.
dc.format.mimetype	application/pdf
dc.identifier.uri	http://hdl.handle.net/1853/60703
dc.language.iso	en_US
dc.publisher	Georgia Institute of Technology
dc.subject	Polymers
dc.subject	Catalyst
dc.subject	Cooperative catalysis
dc.subject	Hydroboration
dc.subject	Micelle
dc.subject	C-H arylation
dc.subject	Cascade catalysis
dc.title	Design of polymer architectures for catalysis
dc.type	Text
dc.type.genre	Dissertation
dspace.entity.type	Publication
local.contributor.advisor	Jones, Christopher W.
local.contributor.corporatename	School of Chemistry and Biochemistry
local.contributor.corporatename	College of Sciences
relation.isAdvisorOfPublication	27088bc0-032b-40d1-b0a7-7f2f25b5bdeb
relation.isOrgUnitOfPublication	f1725b93-3ab8-4c47-a4c3-3596c03d6f1e
relation.isOrgUnitOfPublication	85042be6-2d68-4e07-b384-e1f908fae48a
thesis.degree.level	Doctoral