Thiourea-Catalyzed C-F Bond Activation: Amination of Benzylic Fluorides

Abstract

We describe the first thiourea-catalyzed C-F bond activation. The use of a thiourea catalyst and Ti(OiPr)₄ as a fluoride scavenger allows the amination of benzylic fluorides to proceed in moderate to excellent yields. Preliminary results with S- and O-based nucleophiles are also presented. DFT calculations reveal the importance of hydrogen bonds between the catalyst and the fluorine atom of the substrate to lower the activation energy during the transition state.

Keywords: C−F activation; benzyl amines; benzyl fluorides; organocatalysis; thiourea.