Date of Award

5-2010

Degree Name

Master of Science

Department

Chemistry

First Advisor

Dr. James J. Kiddle

Second Advisor

Dr. Elke Schoffers

Third Advisor

Dr. John Chateauneuf

Access Setting

Masters Thesis-Campus Only

Abstract

For years, the Wittig reaction has being utilized for carbon-carbon olefination because of its capability of selectively forming double bonds. However, less attention has been paid to the development of its asymmetric version. Over the decades, organocatalysis has been a rapidly developing field in catalysis. Chiral Bronsted Lewis acid catalysis and crural hydrogen bonding catalysis have played a significant role in the field of chemistry in the past few years. Increasing publications have witnessed the exploration of these catalysts in asymmetric organic synthesis. Accessibility to these catalysts has encouraged researchers to undertake challenges to asymmetrically synthesize organic molecules.

Here we employed such catalysts in asymmetric versions of the Wittig reactions of 4- substituted cyclohexanones with stabilized ylides to form axially chiral compounds under different reaction conditions. Of all the chiral catalysts used in the reaction, TADDOL {(R,R)-(-)-4,5-Bis[hydroxyl(diphenyl)-methyl]-2,2-dimethyl-1,3-dioxolane} was found to be capable of producing a product with moderate enantiomeric excess. Even though the overall observed degree of selectivity was not optimum, the concept can be utilized in selectively synthesizing large organic compounds.

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