Generation and Capture of Functionalized Fluorocarbanions

Article abstract of DOI:10.1021/ja00331a024

Fluorocarbanions that are produced by the addition of nucleophiles to fluoroolefins can be trapped in many cases with CO2 to form β-substituted polyfluoropropionates directly and in excellent to modest yields.The scope of the reaction encompasses the nucleophiles CN^-, N3^-, C6H5O^-, RS^-, (RO)2P(O)^-, CF3CH2O^- and even Cl^-, and the fluoroolefins CF2=CF2, CF2=CFCl, CF2=CFOCF3, and CF2=CFOC3F7.Theoretical calculations of the relative energies for rotamers of four fluorocarbanions support the idea that successful trapping of a fluorocarbanion depends upon formation of a relatively stable conformer in which the incoming nucleophile and unshared electron pair are anti.