Radical Pentafluoroethylation of Unactivated Alkenes Using CuCF2CF3.

ABSTRACT

We have found that the CuCF2CF3 complex generated from low-cost pentafluoroethane is a convenient and practical source for the CF2CF3 radical under aerobic conditions at room temperature. Using this system, readily available unactivated alkenes can be pentafluoroethylated to provide novel allylic CF2CF3 compounds with excellent E-selectivity and functional group tolerability. Mechanistic studies including TEMPO-CF2CF3 trapping and radical clock experiments provided strong evidence for radical pathways, offering a new opportunity for copper-mediated radical perfluoroalkylation.