Synthesis and Study of Organic Amide-containing Silanediols, Disiloxanediols, and Biologically Relevant Organosilicon Compounds
Author | : Sean Ora Wilson |
Publisher | : |
Total Pages | : |
Release | : 2014 |
ISBN-10 | : 1321364296 |
ISBN-13 | : 9781321364293 |
Rating | : 4/5 (96 Downloads) |
Book excerpt: The synthesis and properties of organosilanols and other organosilicon compounds are important for the further understanding of this class of molecule and application as hydrogen-bonding catalysts and bioactive structures. This dissertation presents the development of synthetic methodology of various organosilicon compounds. These compounds were studied in a variety of ways to better understand the stability and hydrogen-bonding nature of this class of compound. Chapter Zero introduces the unique properties of silicon in comparison to carbon. The prior literature highlighted focuses on synthetic strategy and associated challenges as well as the investigation of molecular properties of accessed compounds. Chapter One describes my development of synthetic methodology to access amide- containing silanediols including an enantioenriched variant. I describe the intra- and intermolecular hydrogen properties of these bifunctional silanediols using NMR and IR spectroscopy as well as X-ray crystallography. I also demonstrate the stability towards degradation of these compounds using 1H NMR spectroscopy and ESI-MS. Chapter Two describes the application of silanediols as hydrogen-bonding catalysts in the Michael addition of nucleophiles to trans-B-nitrostyrene with yields up to 99%. I describe NMR spectroscopy studies that provide evidence for silanediol self-association in reaction conditions and the importance of self-association in substrate activation. Chapter Three describes the use of NMR spectroscopy to elucidate hydrogen-bonding patterns in solution. This chapter demonstrates the first example of using DOSY NMR spectroscopy to study the hydrogen-bonding patterns of silanediols in solution. The hydrogen-bonding networks of silanediols in the presence of pyridine derivatives are described and compared to solid-state X-ray crystallography studies. Chapter Four describes the catalytic ability of disiloxanediols and compares it to that of silanediols. This chapter describes the first in depth investigation of disiloxanediols as organocatalysts. I demonstrate the ability of disiloxanediols to catalyze the Michael addition of nucleophiles to trans-B-nitrostyrene. I also demonstrate disiloxanediol catalysis of an anion- binding reaction. I describe NMR spectroscopy studies that demonstrate the differences between disiloxanediols and silanediols that account for the observed reactivity. Chapter Five describes the synthesis and properties of medicinally relevant organosilicon compounds. I describe the solving of an X-ray crystal structure of an N-Boc-iminooxindole annulation product and the implications on the mechanism of an allylsilane annulation reaction. This chapter will also describe methodology to access silyl glycolipids and demonstrates the first synthesis of a silyl Lipid A analog for which the biological activity will be discussed. The synthetic methodology and hydrogen-bonding properties of spirooxindole silanediols for the application of metalloprotease inhibitors will also be discussed.