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

The aza-Wittig reaction between Ar f NPPh3 [Ar f = 3,5-(CF3)2C6H3] and 1,1,1,5,5,5-hexafluoro-2,4-pentanedione affords a new, highly fluorinated β-diketimine, 1. Metalation by mesitylcopper(I) in benzene gives rise to the Cu(I) β-diketiminate as its η2-benzene 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-Ar f group.