Physical Sciences and Mathematics Commons^™

Investigation Of N-Sulfonyliminium Ion Triggered Cyclizations For The Synthesis Of Piperidine Scaffolds, Kaitlyn Birkhoff

Honors Theses

In consideration of the on-going global pandemic, immediate access to Food and Drug Administration approved pharmaceutical medications and vaccines is a matter of utmost priority to our national healthcare system. One significant modality in managed care is the dispensation of prescription drugs for the prevention or treatment of illnesses and diseases. According to the Centers for Disease Control and Prevention, physicians order and provide over 2.9 billion prescriptions each year with analgesics, antihyperlipidemics, and dermatological agents being the most prescribed therapeutic classes. Within those classes exists a disparate variety of chemical structures that must be prepared on a metric ton …

Techniques For The Enantioselective Asymmetric Synthesis Of Benzyl Substituted Malonic Acid Esters, Madison Hansen

Honors Theses

A popular method for the enantioselective synthesis of substituted malonic half esters is hydrolysis via Pig Liver Esterase (PLE), however some substrates produce low enantiomeric excess, namely benzyl-substituted malonic esters. Presented here are alternative methods explored for this synthesis, the first being phase-transfer catalyzed hydrolysis via N-benzyl quaternary ammonium salts derived from cinchona alkaloids. The second method utilized chiral auxiliary directed benzylation with auxiliaries including menthol and oxazolidinones. Though unsuccessful, this research provided valuable groundwork in the investigation for the enantioselective asymmetric synthesis of benzyl-substituted malonic acid esters.

Keywords: Pig Liver Esterase, Enantioselectivity, Phase-Transfer Catalysis, Cinchona Alkaloids, Quaternary Ammonium …

An Exploration Of Pyrrole Groups On The Enantioselectivity Of Pig Liver Esterase, Brian Long

Honors Theses

Pig Liver Esterase (PLE) is a serine protease enzyme that can interact with one side of a diester to hydrolyze the ester to a carboxylic acid, and research has found that the level of hydrophobicity of side groups can impact the enantioselectivity of PLE hydrolysis.1, 2 The Jones Model is what current researchers use to model the active site of PLE, but the nature of its binding pockets, namely the Hydrophobic Long (HL) pocket, has been called into question.3 Dimethyl 2-((pyrrole-2-yl)methyl)-2-methylmalonate was prepared to be subjected to PLE hydrolysis to see whether enantioselectivity was found. Chiral HPLC revealed 25.32% enantiomeric …

Progress Towards An Aza-Michael Addition To Ketones, Bowman Potter

Honors Theses

The aza-Michael addition to unsaturated ketones under neutral to mildly basic condition is a difficult transformation due to the inherent unreactivity of ketones toward the addition of weak nucleophiles. This thesis reports on efforts to develop an environmentally friendly, stereoselective and low-cost organo-catalyzed aza-Michael reaction between unsaturated ketones and nitrogen nucleophiles, such as phthalimide, under neutral to mildly basic conditions using the most inexpensive chiral secondary amine catalyst, proline.1 Both proline and the organic base triethylamine were found to be catalytic in the testing platform of cyclohexen-2-one and phthalimide, and another testing platform of 4-hexen-3-one and phthalimide. Likewise, when screened …