UC Berkeley

The following dissertation discusses the development and mechanistic study of reactions that form bonds between fluorine-containing substituents and functionalized aromatic compounds. In particular, this work focuses on transition metal-catalyzed reactions that form aryldifluoromethylcarboxylic acid derivatives and trifluoromethylarenes.

Chapter 1 discusses the properties and applications of fluorine-containing organic compounds and provides an overview of methods for the synthesis of fluoroalkylarenes. The challenges associated with developing transition metal-catalyzed reactions that form aryldifluoromethyl carboxylic acid derivatives and trifluoromethylarenes are also described, and strategies to address these challenges are discussed.

Chapter 2 describes the development of a copper-catalyzed cross-coupling reaction to form aryldifluoroamides from a-silyldifluoroamides and aryl iodides, vinyl iodides, or heteroaryl bromides. The reactions tolerate a variety of functional groups, and the aryldifluoroamide products can be converted to a diverse array of difluoroalkylarenes. The application of this reaction to the synthesis of fluorinated compounds of potential biological interest is also described.

Chapter 3 describes the synthesis, characterization, and reactivity of fluoroenolate complexes of palladium. A systematic study of reductive elimination from fluorinated ester, amide, and nitrile enolate complexes was conducted, and factors influencing the rate of reductive elimination were determined.

Chapter 4 discusses the development of a cross-coupling reaction to form aryldifluoronitriles. In the presence of copper, an a-silyldifluoroacetronitrile reagent couples with aryl halides in moderate to high yields.

Chapter 5 describes the investigation of reductive elimination to form an aryl- trifluoromethyl bond by treatment of arylnickel(II) trifluoromethyl complexes with single-electron oxidants. The reactions occur at room temperature in up to 70% yield.

Chapter 6 discusses the identification of new classes of ligands that promote reductive elimination to form trifluoromethylarenes from arylpalladium(II) trifluoromethyl complexes. The reductive elimination reactions occur under mild conditions and at moderate temperatures.