Date of Award

2017

Document Type

Open Access Dissertation

Department

Chemistry and Biochemistry

Sub-Department

College of Arts and Sciences

First Advisor

Sheryl L. Wiskur

Abstract

This work described herein focuses on the silylation-based kinetic resolution methodology developed by the Wiskur group in 2011. It is a powerful method for the separation of a single enantiomer from a mixture of racemic secondary alcohols. Chapter one is a summary of the background and related works of this methodology.

In chapter two, the silylation-based kinetic resolution of various trans 2-arylcyclohexanols will be discussed by employing a p-isopropyl triphenylsilyl chloride as the derivatizing reagent with (-)-benzotetramisole as the catalyst. The diastereoselective and enantioselective of trans alcohols over the cis will be investigated and a facial one-pot reaction sequence will be introduced.

In an effort to understand the mechanism, Chapter 3 will focus on our interest of chirality transmission from point chirality to helical chirality in our silylation-based kinetic resolution system. Circular dichroism spectroscopy, crystal structure studies and computational modelling were applied with various synthesized triarylsilyl ether to show that point chirality can induce helical chirality in triarylsilyl groups. The understanding of chirality transmission between the alcohol and the triarylsilyl group can be extrapolated to explain the importance of the phenyl groups in silylation-based kinetic resolutions.

Further endeavors to understand the mechanism of silylation-based kinetic resolution will be addressed in Chapter 4. The efforts will be focused on the investigations of directionality of nucleophilic displacement of silicon (retention or inversion) in the mechanism. This can be achieved by studying the stereogenic center at silicon of enantiopure chiral silane. The ultimate goal of the work is to depict a complete mechanistic picture of silylation-based kinetic resolution, along with other approaches.

Included in

Chemistry Commons

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