Copper(I) Complexes of a Heavily Fluorinated (beta)-Diketiminate Ligand: Synthesis, Electronic Properties, and Intramolecular Aerobic Hydroxylation

The aza-Wittig reaction between Arf-N=PPh3 [Arf = 3,5-(CF3)2C6H3] and 1,1,1,5,5,5-hexafluoro-2,4-pentanedione affords a new, highly fluorinated (beta)-diketimine, 1. Metalation by mesitylcopper(I) in benzene gives rise to the Cu(I) (beta)-diketiminate as its (eta)^2benzene adduct, 2a. Copper(I) carbonyl complexes of 1, and of three less-fluorinated analogues, have been generated in situ and compared by IR spectroscopy; the two backbone CF3 groups exert a stronger electronic influence than the four N-aryl CF3 groups. Dinuclear adduct 2b reacts readily with O2, leading to ortho-hydroxylation of a ligand N-Arf group.