UC Riverside

The ability to create new carbon–carbon bonds impacts pharmaceutical, agrochemical, and materials development. While this field has progressed significantly, the most common methods rely heavily on the usage of expensive, precious metal catalysts. In this dissertation, three methods will be presented that expand the synthetic toolbox for forging C–C bonds through use of inexpensive, readily-accessible metals.Iron is a particularly attractive catalyst due to its high earth-abundance and ease of handling. Fenton’s reagent, a mixture of Fe(II), hydrogen peroxide, and sulfuric acid that catalyzes the radical alkylation of pyridines (i.e., the Minisci reaction), was inspiration for our synthesis of diarylmethanes, which occurs through C–H abstraction of methanol followed by electrophilic aromatic substitution. Iron was also used to expand the utility of the Friedel–Crafts reaction. Here, a dual Brønsted/Lewis acid catalytic system was developed, enabling arene alkylation with unactivated tertiary alcohols, reactants that previously required heterogeneous superacids to achieve reactivity. The final part of the dissertation focuses on using cobalt to replace rhodium for directed C–H activation. Departing from conventional reactivity with electron-poor alkenes and alkynes, our lab’s interest is in developing novel methods that include electron-rich coupling partners, ultimately expanding the types of products that can be synthesized. Specifically, exploiting cobalt for C–H activation of arenes bearing a simple amide directing group and its subsequent coupling with electron–rich alkynes, an underexplored substrate class, will be presented.