We commenced our investigation by applying our previously reported protocol to 1-pentafluoroethylnaphthalene (1; Table , entry 1). However, the reaction of 1 with 10 equiv. of Me2PhSiH (2 equiv. of Si-H relative to the amount of C-F bonds) in the presence of CsF and a catalytic amount of Ni(cod)2 and 1,3-diisopropylimidazol-2-ylidene (IiPr) did not give 1-(2,2,2-trifluoroethyl)naphthalene ( ), but instead produced the exhaustive hydrodefluorination product 1-ethylnaphthalene (3) in 37% yield. We also observed the formation of small amounts of alkyl silanes 4 and 5 in the reaction mixture.