Abstract:
Fluoride has the worst leaving group ability of the halogen series in nucleophilic substitution reactions on alkyl halides (leaving group ability: I– > Br– > Cl– >> F–). It is therefore not surprising that reactions involving the use of fluoride as a leaving group on a sp3 carbon are uncommon.
This talk will present a series of synthetic transformations involving the use of a C(sp3)–F bond activation as a key step. In particular, approaches to monofluoroalkenes from 3,3-difluoropropenes via metal-catalyzed or conventional reactions will be presented. Nucleophilic substitution reactions of activated alkyl fluorides in aqueous solvent or mediated by a triol will also be discussed. Finally, we will examine the effect of stronger hydrogen-bond donor solvents on the reaction pathway. As such, reactions of benzylic fluorides in Friedel-Crafts reactions will be presented.