Regiospecific Replacement of Fluorine by Hydrogen in an Aromatic Ring Induced by a Rare Earth Organometallic

Article abstract of DOI:10.1016/S0040-4039(00)79974-6

Pentafluorobenzoic acid reacts with YbCp2(dme) to yield, after hydrolysis, 2,3,4,5-tetrafluorobenzoic acid.Conversion is near quantitative with activated magnesium as a coreductant and there is evidence for catalytic turnover in ytterbium on addition of a cyclopentadiene source.Reduction of 2,6-F2C6H3CO2H to o-FC6H4CO2H and of o-FC6H4CO2H to PhCO2H has also been achieved.