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)(2)C6H3] 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-cliketiminate as its eta(2)- 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 O-2, leading to orthohydroxylation of a ligand N-Ar-f group.