Enantioselective -Fluorination of Carbonyl Compounds: Organocatalysis or Metal Catalysis?

摘要

Fluorine occupies a very special position in the periodic table. As the most electronegative element, incorporation of fluorine into organic molecules perturbs the electron density of the compound over several sigma bonds, affecting the pKa values of XH bonds over a long range. In contrast to other carbon-halogen bonds, the carbon-fluorine bond is very strong and aliphatic fluorinated compounds are attacked by nucleophiles only with difficulty.[1] In medicinal chemistry applications, fluorinated compounds impart substantial metabolic stability to drug candidates.[2] These highly advantageous effects associated with fluorine substitution have motivated a truly intense effort into the synthesis and characterization of novel fluorine-containing compounds.