Sulfone as traceless activating group: Divergent synthesis of α-fluoroamides with C–F quaternary stereocenters

A novel approach to α -fluoroamides bearing a C–F quaternary stereocenter is reported herein. With sulfone installed as the activating group, an alkyl group as well as a fluorine atom was introduced successively under mild conditions. Subsequently, heterolytic fission of the C–S bond occurred smoothly under photoredox conditions to afford a tertiary radical, which then engaged in varied intramolecular cyclizations depending on substrate structure and condition applied, rendering sulfone an overall traceless activating group. With sulfone as an overall traceless activating group, divergent synthesis of α-fluoroamides with C–F quaternary stereocenters was accomplished from simple starting materials, offering a new strategy for versatile construction of C–F quaternary stereocenters.