Synthesis and Evaluation of Silanol-based Hydrogen-bonding Catalysts for Nitrostyrene and Nitroso Addition Reactions. Allylic Silanes as Mild and Effective Nucleophiles for the Stereoselective Formation of 2,3'-Pyrrolidinyl Spirooxindoles.

摘要

The first chapter of this document describes the synthesis and hydrogen-bonding properties of several silanol-based organocatalysts. 1H NMR spectroscopic binding experiments were used to determine whether or not these catalysts interacted with nitrosobenzene. Keq data was obtained for the binding of these catalysts with an N-methylphenylpyrazinone indicator using UV/Vis spectrophotometry. The results of these experiments led to catalyst screening for the reactions described in Chapter 2.;The second chapter of this document describes experiments used to determine the utility of organic silanols as catalysts for trans-beta-nitrostyrene addition reactions and the nitroso aldol reaction. The nitrogen vs. oxygen binding preference of silanol catalysts was investigated using nitrosobenzene as a model electrophile. 1H NMR spectroscopic studies were used to determine product formation and further transformations when the nitroso aldol reaction was run in the presence of silanol-based catalysts.;The third chapter of this document describes spirocyclization reactions between crotylsilane nucleophiles and Boc-iminooxindoles in the presence of Lewis acid metal salts. A green, economical and highly efficient N-Boc deprotection method using the acidic clay montmorillonite K10 is described. The total synthesis of previously unreported crotylsilane bearing carboxylic acid functionality is disseminated, along with data regarding its utility as a nucleophile for spirocyclization reactions.