Asymmetric Fluorination of tert-Butoxycarbonyl Lactones and Lactams

Significance

The authors describe the enantio­selective fluorination of lactones and lactams. They extend their use of the bisphosphine-Pd-water complexes to generate the proposed chiral enolate. The use of 2,6-lutidine as a co-activator was necessary for the less-acidic lactams. The use of alcoholic solvents was necessary as reactions performed in normal organic solvents were extremely slow. Both five- and six-membered lactones and lactams work well in this reaction giving products with >90% ee.