Tian Zhang

Date of Award

Fall 2019

Document Type

Open Access Dissertation

Department

Chemistry and Biochemistry

First Advisor

Sheryl L. Wiskur

Abstract

This dissertation focuses on studies of silylation-based kinetic resolution methodology developed by the Wiskur group, which is a powerful method for the separation of a single enantiomer from a mixture of racemic secondary alcohols. Chapter 1 introduces the background of our silylation-based kinetic resolution..

Chapter 2 involves mechanistic studies of electrostatic interactions in controlling enantioselectivities of our silylation-based kinetic resolution. Electrostatic interactions between a silylated isothiourea intermediate and an ester π system is determined via linear free energy relationship study. To be specific, how variations in sterics and electronics affect the selectivity of a silylation-based kinetic resolution.

Chapter 3 is the following research of chapter 2 on the electrostatic interaction in controlling the enantioselectivities. Similar research approaches such as linear free energy relationship study is applied. Computation data on the proposed intermediate and transition state in silylation-based kinetic resolution our will be discussed.

Chapter 4 introduce an optimization of polystyrene-supported triphenylsilyl chlorides that were developed in our group in obtaining enantioenriched secondary alcohols via a chromatography-free isolation. Second generation’s polystyrene-supported triphenylsilyl chloride is proposed by incorporating polar methyl methacrylate to the adjacent position of active site, promoting a more polar microenvironment. Effect of variations in polarity and percentage of incorporating monomer will be discussed.

Rights

© 2019, Tian Zhang

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