Metal-Catalyzed Enantioselective Dicarbofunctionalization of Alkenylboron Compounds

Abstract

This dissertation will discuss the development of three methodologies for the enantioselective synthesis of organoboron compounds. The first chapter will discuss the initial discovery and development of a palladium-catalyzed reaction that enables the combination of an organolithium, an organoboronic ester and C(sp2)-OTf electrophiles in an enantioselective fashion. This conjunctive cross-coupling takes place through a 1,2-metallate shift which is induced from an alkenylboron ‘ate’ species through interaction with the palladium catalyst. The second chapter of this manuscript will discuss the development of the first nickel-catalyzed version of the conjunctive cross- coupling reaction, which operates enantioselectively with in situ generated 9-BBN boranes. The third and last chapter will discuss the development of complementary method to the conjunctive cross-coupling which enables the enantioselective addition of organozinc reagents and alkyl halides across alkenylboronic esters. This system departs from the metal-induced 1,2-metallate shift mode of reactivity in favor of a Ni- catalyzed radical/addition cross-coupling cascade reaction. This process can be operated in both an inter- and intra-molecular fashion to afford enantiomerically-enriched alkylboronic ester compounds.