Trifluoromethylation of Alkyl Radicals in Aqueous Solution

Abstract

The copper-mediated trifluoromethylation of alkyl radicals is described. The combination of Et₃SiH and K₂S₂O₈ initiates the radical reactions of alkyl bromides or iodides with BPyCu(CF₃)₃ (BPy = 2,2'-bipyridine) in aqueous acetone at room temperature to afford the corresponding trifluoromethylation products in good yield. The protocol is applicable to various primary and secondary alkyl halides and exhibits wide functional group compatibility. A mechanism involving trifluoromethyl group transfer from Cu(II)-CF₃ intermediates to alkyl radicals is proposed.