Development of Methods for the Synthesis of Boron-Containing Cyclic Structures

Abstract

This dissertation presents research on novel synthetic methodologies and mechanistic studies focused on boron chemistry in organic synthesis. Chapter one introduces the “sam” auxiliary, a chiral ligand designed to enhance stereoselectivity in cycloaddition reactions. The auxiliary's synthesis, installation on alkenyl boron species, and applications in cycloadditions with nitrones, glycine imine ylides, and radicals are discussed, demonstrating high-yielding and stereoselective results. Chapter two introduces a catalytic enantioselective Suzuki-Miyaura cross-coupling reaction for desymmetrizing vicinal bis(boronic) esters, synthesizing enantiomerically enriched substituted carbocycles and heterocycles while retaining a boronic ester. Mechanistic studies highlighted the cooperative effect of vicinal boronic esters, and practical applications were demonstrated through the synthesis of bioactive molecules. Chapter three discusses the catalytic enantioselective synthesis of disubstituted nortricyclanes as meta benzene isosteres and the acid-catalyzed rearrangement of borylated norbornenes. Boron moieties were crucial for enhancing reactivity and selectivity. Overall, this dissertation demonstrates the potential of boron chemistry in developing new synthetic methodologies, offering valuable insights for advancing organic synthesis and medicinal chemistry.