14. Copper-Mediated Deoxygenative Trifluoromethylation of Benzylic Xanthates: Formation of C(sp3)–CF3 from an O-Based Electrophile

Zhu, L.; Liu, S.; Douglas, J. T.; Altman, R. A.*

Chem. Eur. J. 2013, 19, 12800–12805.

The conversion of an alcohol-based functional group, into a trifluoromethyl analogue is a desirable transformation. However, few methods are capable of converting O-based electrophiles into trifluoromethanes. The copper-mediated trifluoromethylation of benzylic xanthates using Umemoto’s reagent as the source of CF3 to form CCF3 bonds is described. The method is compatible with an array of benzylic xanthates bearing useful functional groups. A preliminary mechanistic investigation suggests that the CCF3 bond forms by reaction of the substrate with in situ generated CuCF3 and CuOTf. Further evidence suggests that the reaction could proceed via a radical cation intermediate.