Physical Sciences and Mathematics Commons^™

Controlled Degradation Of Poly(Ester Amide)S Via Cyclization Of Pendant Functional Groups, Jose Samuel Mejia

Electronic Thesis and Dissertation Repository

Polyesters have been used for many biomedical applications ranging from sutures to drug delivery vehicles. However, their bulk degradation results in an accumulation of acidic byproducts, which is detrimental to the human body. In order to circumvent this problem, as well as to impart new properties and functions to polymers for biomedical applications, poly(ester amide)s (PEAs) have been proposed as a different class of biodegradable polymers. However, up to date, there exists no way to stimulate the degradation of these polymers.

The Gillies research group has previously incorporated self-immolative spacers into polymers and has been able to stimulate their degradation …

The Multicomponent Synthesis Of Pyrroles From Cylcopropane S Using A One Pot Pd(0) Catalyzed Dehydrocarbonylation Protocol, William J. Humenny

Electronic Thesis and Dissertation Repository

Previous work done by the Kerr group has shown that tetrahydro-1,2-oxazines can be efficiently synthesized using a three component coupling reaction between a hydroxylamine, aldehyde and cyclopropane diester. This affords the desired heterocycle efficiently with a wide variety of substitution. When one esters bears an allyl group a Tsuji dehydrocarbonylation reaction may take place resulting in the formation of a 4,5-dihydro-1,2-oxazine. This motif contains a vinylogously acidic proton which is extremely labile and easily deprotonated. Under basic conditions this proton is removed and consequently the N-O bond is cleaved and subsequent condensation occurs forming a pyrrole. Using a sequence of …

Complementary And Self-Complementary Hydrogen Bond Double Helical Complexes, Bhanu P. Mudraboyina

Electronic Thesis and Dissertation Repository

The design of artificial or synthetic strands that self-assemble to form double-helical complexes have been of great interest to chemists and researchers since the discovery of the double helical DNA structure in 1953 by Watson and Crick. Most of the complexes were self-complementary double-helical homodimers and while few heterodimer complexes are also known. The present thesis describes the design, synthesis and characterization of complementary and self-complementary hydrogen bond arrays built from heterocycles such as pyridine, thiazine dioxide and indole connected in different sequences. The sequence-based stabilities, insolubility issues, substitution and preorganization effects in these arrays have been studied in detail. …

Synthesis Of Self-Immolative Monomers And Their Applications In Polymeric Materials, Matthew A. Dewit

Electronic Thesis and Dissertation Repository

Self-immolative spacers are a unique class of molecules employed in a variety of applications, particularly in the biomedical field. Most commonly, they are molecules containing two reactive termini with a capping group at one terminus and a substrate of interest at the other. Upon removal of the capping group, the spacer undergoes an intramolecular reaction that results in its removal from the molecule and liberation of the substrate. These spacers have been extensively studied in monomeric form within prodrugs, as well as to form dendrimers that have been used for applications such as signal amplification, molecular logic gates and amplified …

Progress Towards The Total Synthesis Of Amphidinolide C, Nicholas A. Morra

Electronic Thesis and Dissertation Repository

A second generation catalyst for the Mukaiyama oxidative cyclization for the formation of trans-THF rings is described. Co(nmp)₂, displays increased stability to the reaction conditions, resulting in lower catalyst loadings, lower reaction temperatures, and significantly higher purity and yields of the products. Three procedures have been developed with this new water-soluble catalyst that greatly simplifies the post-reaction purification, making this procedure the premier method of forming trans-THF rings.

This new catalyst has been applied towards the total synthesis of the potently bioactive macrocycle, Amphidinolide C. Herein we report the successful synthesis of several fragments of the …

Synthesis Of (±)-Quebrachamine, Tetrahydroisoquinocarbazoles, And Progress Towards Biselide A And E, Barbora Morra

Electronic Thesis and Dissertation Repository

A variety of methodologies developed in our research group have inspired the three separate projects reported. First, the total synthesis of (±)-quebrachamine was performed in 13 steps and 17.8% overall yield. Highlights of the synthesis include an efficient preparation of a functionalized indole core via a [3+2] annulation cycloaddition reaction between a functionalized nitrile and donor-acceptor cyclopropane and a photo induced 9-membered ring closure.

Secondly, we have reported the most efficent and highest yielding route to several tetrahydroisoquinocarbazoles, where the core was prepared in six steps from tryptophol in 51% overall yield. This work highlights for the first time the …