Date of Award

Summer 8-15-2021

Author's School

Graduate School of Arts and Sciences

Author's Department


Degree Name

Doctor of Philosophy (PhD)

Degree Type



Two new enantioselective methodologies have been developed that have important implications for the asymmetric synthesis of β-amino acids and their derivatives. First, chiral amidine-based catalyst (ABC) HBTM-2 catalyzed an asymmetric cyclocondensation between in situ activated fluoroacetic acid and N-sulfonyl aldimines to give α-fluoro-β-lactams in highly enantioenriched form, achieving modest to excellent diastereoselectivities. These reactive lactams can then be quenched with various alcohols and amines to deliver the α-fluoro-β-amino acid derivatives in moderate isolated yields. Secondly, bifunctional double hydrogen bond donor-amine organocatalysts enable the catalytic alcoholysis of various racemic N-carbalkoxy-3-substituted isoxazolidin-5-ones, resulting in their kinetic resolution. The enantioenriched unreacted isoxazolidinone and product (easily recyclable via a two-step transesterification-cyclization process) can undergo quantitative N-O bond cleavage by hydrogen to give β-amino acids in N-protected form. The fourth chapter of this dissertation, an extension of previous achievements in our group, describes the development of an organocatalyzed rearrangement of S-phenacyl thioesters that is mechanistically distinct from our previously published work. Additionally, more examples of asymmetric tandem rearrangements of S-aryl thioesters were demonstrated.


English (en)

Chair and Committee

Vladimir B. Birman

Committee Members

Marcus Foston, Kevin Moeller, John-Stephen Taylor, Timothy Wencewicz,