Copper-mediated deoxygenative trifluoromethylation of benzylic xanthates: generation of a C-CF(3) bond from an O-based electrophile.
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.
Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66045 (USA), Fax: (+1) 785-864-5326.
Lingui
L
Zhu
Shasha
S
Liu
Justin T
JT
Douglas
Ryan A
RA
Altman
D002244:Carbon / Q000737:chemistry; D002384:Catalysis; D005617:Chlorofluorocarbons, Methane / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry
D005617:Chlorofluorocarbons, Methane; D002244:Carbon; D003300:Copper; D010100:Oxygen; C009554:fluoroform
copper; fluorine; radical cation; synthetic methods; trifluoromethylation