Copper-catalyzed trifluoromethylation of alkenes: synthesis of trifluoromethylated benzoxazines

Abstract

A simple base and ligand free copper catalyzed method for the construction of trifluoromethylated benzoxazines has been developed by using Umemoto's reagent. It involves the oxidative difunctionalization of alkenes through tandem C–O and C–CF₃ bond formations. Furthermore, synthesized benzoxazines were selectively converted into trifluoromethylated allylic and (E)-vinylic benzamides by the treatment of KO^tBu and CH₃Li, respectively.