Physical Sciences and Mathematics Commons^™

Part I: Studies Towards Asymmetric Α-Halogenation And Mechanistic Studies Of The Acrylate System With Organocatalyst And Part Ii: Synthesis Of Α-Aryl Quaternary Carbon Centers, Maria Shevyrev Shteynbuk

Theses and Dissertations

Organocatalytic transformations and asymmetric α-halogenation have become an important and dynamic research topic in organic chemistry in recent years. Despite the growing research in asymmetric halogenation of carbonyl compounds, such as aldehydes and ketones, there are no current examples in the literature of asymmetric halogenation of enolic systems even though many proposed reaction mechanisms go through enolate form. The research presented is the first example of enantioselective α-chlorination and α-bromination of α-hydroxyacrylate using organocatalysis and NMR studies towards achieving asymmetric induction of the enolic system. Despite the many publications that show when an organocatalyst binds to an aldehyde or ketone, …

I. Studies On The Organocatalytic Formation Of Quaternary Stereocenters. Ii. Studies On The Claisen Rearrangement As A Route To Quaternary Stereocenters. Iii. Asymmetric Synthesis Of Aldehydes Bearing Quaternary Carbon Centers Via The Decarboxylative Asymmetric Allylic Alkylation, Eduardo Alberch

Theses and Dissertations

The asymmetric synthesis of all carbon quaternary stereocenters poses a particular challenge due to the steric congestion inherent in the formation of such centers and has been the object of intense research these last 20-30 years. However, the amount of literature for the synthesis of aldehydes bearing quaternary stereocenters via enolate type chemistry is much more limited due to problems associated with the alkylation of such substrates including such types as Cannizzaro and Tischenko related reactions or self aldol condensations. The formation of aldehydes with quaternary stereocenters via use of enolate equivalents such as the DAAA (decarboxylative asymmetric allylic alkylation) …

Infrared Light Induced Bending Of Liquid Crystalline Elastomer Composite-Silicone Bilayer Films, Maika Moua

Theses and Dissertations

This research centers on infrared (IR) light-induced bending of liquid crystalline elastomers (LCE) composite-silicone bilayer films. Two new developments are presented in this thesis. First, the reversible infrared (IR) induced bending of 0.1% (w/w) single walled nanotube (SWNT)-LCE/silicone bilayer films were successfully prepared and used for fabrication of functioning devices such as folding, grabbing, and crawling structures. Second, the use of adding a filler (absorbs specific wavelength range), such as Dye 1002, into the LCE matrix achieved wavelength selectivity in LCE systems. The 0.2% (wt/wt) Dye 1002-LCE/silicone bilayer films demonstrated bending under a 980 nm laser source but no bending …

Part 1. Design And Synthesis Of Cysteine/Cystine Prodrugs And Bioisosteres Including Symmetrical And Unsymmetrical Disulfides Designed To Increase Cystine Levels In The Cns In Order To Drive The Cystine/Glutamate Antiporter: A Novel Treatment For Schizophrenia And Drug Addiction. Part 2. Design And Synthesis Of Subtype Selective Ester Bioisosteres Of Bzr Ligands For Gabaa/Benzodiazepine Receptors To Enhance Metabolic Stability, Edward Merle Johnson Ii

Theses and Dissertations

Part 1. Schizophrenia is a debilitating disorder that affects almost 1% of the world's population; pharmacotherapy expenditures for this disorder exceed $10 billion dollars even though existing medications exhibit a poor safety/efficacy profile. It is estimated that 75% of patients discontinue drug treatment, in part due to poor safety/efficacy. The current data set demonstrates that cysteine prodrug NAC reverse the behavioral and neurochemical effects of PCP used to model schizophrenia.

As a result cysteine prodrugs represent a highly novel approach to treating schizophrenia; indeed, these compounds may ultimately be more effective than existing medications because these drugs target the pathology …

Part I. The First Enantiospecific, Stereospecific Total Synthesis Of The Indole Alkaloid Ervincidine. Part Ii. The Synthesis Of Alpha 5 Subtype Selective Ligands For Gaba(A) /Benzodiazepine Receptors, Sundari K. Rallapalli

Theses and Dissertations

Part I. The first enantiospecific, stereospecific total synthesis of ervincidine 89 has been accomplished from commercially available D-(+)-tryptophan 37 which has served both as the chiral auxiliary and the starting material. Moreover, this is the first synthesis which unequivocally sets the stereochemistry of the hydroxyl group at C-6 in sterospecific fashion, as well as the C-16 hydroxy methyl group. The stereospecific conversion of D-(+)-tryptophan 37 into the key template (−)-Na-H, Nb-benzyl tetracyclic ketone 49 via the asymmetric Pictet-Spengler reaction (600 gram scale) and Dieckmann cyclization on multi-hundred gram scale was reduced to only two reaction vessels. The optically active tetracyclic …