Synthesis and Decarboxylative Coupling of Sulfonyl Acetic Esters

Abstract

The synthesis and palladium-catalyzed decarboxylative allylation (DCA) of α-sulfonyl allyl esters is the central focus of this dissertation. Specifically we describe the development of the racemic reaction in which the scope and mechanism are investigated. In addition, we demonstrate the superiority of Pd-catalyzed DCA to current methodology for the formation of tertiary sulfones. Furthermore, we demonstrate how the chemistry of the sulfone and the DCA, we developed, can be used in concert to obtain products that are not easily accessible. We next developed an asymmetric variant of the reaction in which the asymmetry comes from the substrate itself and not an outside source. Specifically, we observed high levels of conservation of enantioenrichment when the reaction proceeded in the presence of an achiral or racemic catalyst. We investigated this unusual behavior and propose a mechanism to explain the observation. Again, we compare the DCA to existing methodologies and demonstrate that it compares very favorably synthetically and in part answers unsolved challenges in asymmetric organic chemistry. In the course of this work it became apparent that the synthesis of our starting materials would also be a significant contribution to the field of organic chemistry. We have detailed the syntheses of both asymmetric and racemic sulfonyl acetic esters.