UC Davis

Hydrogen bonding is crucial for all biological systems. This dissertation explores the importance of the synthesis and subsequent desymmetrization of silanediols and the hydrogen-bonding interactions crucial for catalysis. The introduction presents the discovery of organosilanols and introduces the properties and importance of organosilanols. Notable reactions in silica gel catalysis are presented. Finally, silanols as catalysts in the Franz group are discussed, which sets the precedent for the need for the synthesis of chiral-at-silicon compounds.Chapter two details my contributions to the organocatalytic asymmetric synthesis of silicon-stereogenic siloxanols. The initial understanding of the organocatalyst-substrate complex was investigated by Jacob J. Dalton, Ph.D. who performed a co-crystallization experiment which revealed a two-point hydrogen-bonding interaction involving the imidazole and amide of the organocatalyst. My contributions involve the design, synthesis, and evaluation of organocatalyst analogs. Structural changes in the organocatalyst validated the crucial role of the imidazole in reactivity and selectivity. Additionally, the chapter explores the efforts towards substrate scope expansion. The hydrogen-bonding interactions present in the solid-state were verified using 1 H NMR binding studies and a correlation of binding affinity and enantioselectivity was discussed. This research represents my contributions to the first example of a Lewis base-catalyzed desymmetrization of prochiral silanediols.  Chapter three extends the desymmetrization of prochiral silanediols for the synthesis of chiral 1,3-disiloxanediols. The initial exploration for the synthesis of chiral 1,3-disiloxanediols gained insight into the role of the chlorosilane reaction partner. The chapter presents access to the first example of a diaryl silanediol to produce a stereogenic siloxanol in high selectivity. Additionally, the potential application of chiral 1,3-disiloxanediols as hydrogen-bonding organocatalysts were briefly explored. 1 H NMR binding studies were used to probe the hydrogen-bonding interactions that alluded to the role of the chlorosilane binding partner. Moreover, 1 H NMR binding studies, analyzed by 1 H NMR, were conducted to explore the binding affinity of chiral 1,3-disiloxanediols with pyridine as a model Lewis base. The synthesis of chiral 1,3-disiloxanediols in high yields remains a priority.