Oxidatively induced aryl-CF3 coupling at diphosphine nickel complexes

This communication describes the synthesis of a series of diphosphine Ni^II(Ph)(CF₃) complexes and studies of their reactivity toward oxidatively induced Ph–CF₃ bond-forming reductive elimination. Treatment of these complexes with the one-electron outer-sphere oxidant ferrocenium hexafluorophosphate (FcPF₆) affords benzotrifluoride, but the yield varies dramatically as a function of diphosphine ligand. Diphosphines with bite angles of less than 92° afforded <10% yield of PhCF₃. In contrast, those with bite angles between 95 and 102° formed PhCF₃ in yields ranging from 62 to 77%.