Metallocenium Incorporated Lewis and Brønsted Acid Catalysts: Synthetic Routes and Catalytic Applications

Abstract

Lewis acids are some of the most widely used reagents for organic transformations. They are prized for their reactivity but are often sensitive to air and water. The metallocenium scaffold offers many advantages to the improvement of both robust homogeneous Lewis acids and asymmetric catalysts. Chirality is vitally important to natural systems including for the development of pharmaceuticals and agrochemicals. In this document, I first describe the development of air and moisture tolerant, reactive metallocenium Lewis acid catalysts, and their use in Friedel-Crafts alkylation and Diels-Alder cycloaddition reactions. Furthermore, I combined these active substituents with the organocatalytic thiourea scaffold in a model study to determine catalytic activity in acid catalyzed reactions. Finally, I developed a general procedure which combines aminocobaltocenium hexafluorophosphate with a variety of chiral isothiocyanates and explored the selectivity of these species in the Friedel-Crafts reaction of indole and trans- β-nitrostyrene.