2011 Theses Doctoral

Part I: Development of New Methods for Multicatalysis: Bismuth(III) Triflate-Catalyzed Hydrofunctionalizations . . .

Kelly, Brendan Douglas

This thesis describes the development of novel synthetic methods in two areas of chemical research: Multicatalysis and the aromatic activation of alcohols. The first chapter, encompassing multicatalysis, reveals the design and realization of an innovative hydro-functionalization method. This method is examined in the context of designing multicatalytic processes to access privileged chemical architectures, which unite a nucleophilic addition event with the hydrofunctionalization reaction. The resulting multicatalytic methods capably effect the formation of complex heterocyclic compounds.

The second chapter discloses an innovative paradigm for nucleophilic substitution involving aromatic cation activation of alcohols. The development of efficient chlorination and bromination methods promoted by cyclopropenium cations are discussed. The substrate scope and mechanism of the reaction are also examined. The successful demonstration of these methods established proof of concept and initiated further investigations of the aromatic cation activation strategy.

The final chapter extends the concept of aromatic cation activation of alcohols to additional reaction manifolds. A dehydrative cyclization of diols employing aromatic cations is explored. The efficacy of alternative cyclopropenyl leaving groups is examined and the scope of viable nucleophiles for the aromatic activation strategy is extended. Along with Chapter 2, these seminal investigations have laid the foundation for future advances towards the realization of a general aromatic cation activation strategy.