Fluorination of Unsaturated Carbonyl Compounds using Elemental Fluorine

Inna Vints, Organic Chemistry, Tel Aviv Unniversity, Tel Aviv, Israel

It is well known that fluorine and fluorine-containing substituents frequently affect physical, chemical, and biological properties of organic compounds.  They also have a significant role in drug development. No wonder that there is an ever-increasing demand for new and selective methods for preparation of organic materials containing one or more fluorine atoms.

Unlike all other halogens whose chemistry with olefins is well developed, fluorine is a new comer to this field. Conspicuously, the addition of fluorine to enones is practically unknown. One such family is the flavonoids. They are abundant micronutrients in our diet, possessing various biological activities. Fluorine was successfully added in a syn mode across the double bond of various flavones and chromones. The difluoro derivatives products were easily dehydrofluorinated to form the corresponding 3-fluoroflavones and 3-fluorochromones.

Also a successful fluorination of some unreactive α,β-unsaturated carbonyl compounds has been performed, including chalcones, as well as more complex and biologically important materials such as steroids and triterpenoids. (Scheme 2)