Electrochemically Promoted Oxydifluoroethylation of Alkenes for the Synthesis of Difluoroethylated Benzoxazines and Lactones

An electrochemical oxydifluoroethylation of alkenes involving the anodic oxidative generation of MeCF2 radical has been achieved, which enabled to construct diversified difluoroethylated benzoxazines and lactones in 35-87% yields. Moreover, the developed protocol was also extended to the synthesis of cyclopropyldifluoromethylated benzoxazines. Detailed mechanistic studies indicated the reaction underwent a radical process concerned with tandem C-CF2R and C-O bond formation.