El Diario de Pontevedra : periódico liberal: Ano XXVII Número 7742 - 1910 marzo 1

Copper­(II) aryl species are proposed key intermediates in Cu-catalyzed cross-coupling reactions. Novel three-coordinate copper­(II) aryls [Cu^II]-C₆F₅ supported by ancillary β-diketiminate ligands form in reactions between copper­(II) alkoxides [Cu^II]-O^<i>t</i>Bu and B­(C₆F₅)₃. Crystallographic, spectroscopic, and DFT studies reveal geometric and electronic structures of these Cu­(II) organometallic complexes. Reaction of [Cu^II]-C₆F₅ with the free radical NO_(g) results in C-N bond formation to give [Cu]­(η²-ONC₆F₅). Remarkably, addition of the phenolate anion PhO^– to [Cu^II]-C₆F₅ directly affords diaryl ether PhO-C₆F₅ with concomitant generation of the copper­(I) species [Cu^I]­(solvent) and {[Cu^I]-C₆F₅}⁻. Experimental and computational analysis supports redox disproportionation between [Cu^II]-C₆F₅ and {[Cu^II]­(C₆F₅)­(OPh)}⁻ to give {[Cu^I]-C₆F₅}⁻ and [Cu^III]­(C₆F₅)­(OPh) unstable toward reductive elimination to [Cu^I]­(solvent) and PhO-C₆F₅