The dimeric cinchona alkaloid catalyst, (DQHD)2PHAL, used in conjunction with chlorinated hydantoins, has proven to be an efficient catalyst for enantioselective chlorocyclizations, including lactonizations and cyclizations of various amides and carbamates. In efforts to better understand the underlying mechanism(s), a number of cinchona alkaloid dimers have been synthesized for structure enantioselectivity relationship studies. The goals from this study were to acquire a better understanding of the structural features of (DHQD)2PHAL responsible for high enantioinduction and to search for more effective catalyst scaffolds.Chapter 4 will unveil the design of a novel, chiral C2-symmetric pyridine scaffold. The design of this ligand used a combination of computational and synthetic results to determine an optimal scaffold. After discovering an efficient route to access the desired scaffold as a racemate, the enantiomers were separated via fractional crystallization. Additional efforts were then placed on synthesizing a more activated analog of the catalyst scaffold by installing a 4-amino group.
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