A vitamin B12 derivative catalyzed electrochemical trifluoromethylation and perfluoroalkylation of arenes and heteroarenes in organic media

Abstract

The electrochemical trifluoromethylation and perfluoroalkylation of aromatic compounds mediated by a vitamin B₁₂ derivative as a cobalt-based catalyst has been developed. The Co(I) species of a vitamin B₁₂ derivative, prepared by controlled-potential electrolysis at −0.8 V vs. Ag/AgCl in methanol, reacted with R_fI (R_f = CF₃, n-C₃F₇, n-C₄F₉, n-C₈F₁₇, and n-C₁₀F₂₁) to form a Co–R_f complex. This complex released an R_f radical under visible light irradiation, which then reacted directly with non-activated (hetero)arenes to form the desired fluoroalkylated molecules through direct C–H functionalization. To our knowledge, this is the first report of a naturally derived vitamin B₁₂ catalyzed trifluoromethylation and perfluoroalkylation of aromatic compounds as a cobalt-mediated catalyst.