Gold Catalysis and Fluorine

Performing gold-catalyzed organic transformations in the presence of fluorinating reagents can lead to both fluorinated and non-fluorinated products. Gold(I) complexes can activate alkynes towards nucleophilic attack by fluoride leading to fluoroalkenes under mild conditions. Fluorinated products can also be prepared upon performing gold-catalyzed transformations in the presence of electrophilic sources of fluorine. In most cases, however, the combination of gold and electrophilic fluorinating reagents does not lead to fluorination but delivers products of oxidative homo- or cross-coupling. In these processes the "F+" source is likely acting as a sacrificial two-electron external oxidant performing the key oxidation of gold(I) to gold(III) in the redox cycle. Oxidative coupling is an emerging field of gold catalysis which, when combined with the well-established reactivity of gold as a soft pi.-acid, holds promise as a mild and efficient method for the construction of complex organic molecules.