Fluoroalkylation of Various Nucleophiles with Fluoroalkyl Sulfones through a Single Electron Transfer Process.

The fluoroalkylation of various nucleophilic reagents with (phenylsulfonyl)difluoromethyl (PhSO2CF2)-substituted phenanthridines was achieved to give fluorinated phenanthridine derivatives, which enables the construction of both carbon-heteroatom and carbon-carbon bonds via the substitution of the phenylsulfonyl group. Mechanistic studies indicated that these reactions proceed through a unimolecular radical nucleophilic substitution (SRN1) mechanism. It is worthwhile noting that in the cases of O-nucleophiles ( t-BuO- and PhO-), the addition of t-BuOK/PhCHO could significantly promote the reactions, due to the in situ formation of a highly reactive electron donor species through the interaction of t-BuOK, PhCHO, and the solvent DMF, which can effectively initiate the single electron transfer process.