Copper-Mediated Trifluoromethylation of Benzylic Csp3 -H Bonds.
Trifluoromethyl-containing compounds play a significant role in medicinal chemistry, materials and fine chemistry. Although direct C-H trifluoromethylation has been achieved on Csp2 -H bonds, direct conversion of Csp3 -H bonds to Csp3 -CF3 remains challenging. We report herein an efficient protocol for the selective trifluoromethylation of benzylic C-H bonds. This process is mediated by a combination CuIII -CF3 species and persulfate salts. A wide range of methylarenes can be selectively trifluoromethylated at the benzylic positions. A combination of experimental and theoretical mechanistic studies suggests that the reaction involves a radical intermediate and a CuIII -CF3 species as the CF3 transfer reagent.
['Paeth|Matthew|M|', 'Carson|William|W|', 'Luo|Jheng-Hua|JH|', 'Tierney|David|D|', 'Cao|Zhi|Z|', 'Cheng|Mu-Jeng|MJ|', 'Liu|Wei|W|http://orcid.org/0000-0001-6249-3179']
trifluoromethylation C−H activation copper fluorination late-stage diversification