Fluoride Abstraction Induced by Tris(pentafluoroethyl)difluorophosphorane: A Convenient Way to Synthesize Cationic -Heterocyclic Carbene- and Cyclic (Alkyl)(amino)carbene-Ligated Copper Alkyne and Arene Complexes.

We herein report the convenient synthesis of different -heterocyclic carbene (NHC)- and cyclic (alkyl)(amino)carbene (cAAC)-ligated copper cations using the weakly coordinating tris(pentafluoroethyl)trifluorophosphate counterion ( anion, [(CF)PF]). The reaction of the fluorido complexes [(carbene)CuF] (carbene = NHC, cAAC) - and the tris(pentafluoroethyl)difluorophosphorane (CF)PF in the presence of alkynes or arenes led to fluoride transfer from Cu to the phosphorane with formation of the cationic transition metal complexes [(carbene)Cu()] and the weakly coordinating counteranion [(CF)PF] (). Using this method, the complexes [(IDipp)Cu()] (IDipp = 1,3-bis(2,6-di--propylphenyl)-imidazolin-2-ylidene; = PhC≡CPh, ; PhC≡CMe, ), [(cAAC)Cu()] (cAAC = 1-(2,6-di--propylphenyl)-3,3,5,5-tetramethyl-pyrrolidin-2-ylidene; PhC≡CPh, ; PhC≡CMe, ), [(SIDipp)Cu(CMe)] (), (SIDipp = 1,3-bis(2,6-di--propylphenyl)-imidazolidine-2-ylidene), and [(cAAC)Cu(CMe)] () have been synthesized and characterized. The complexes [(IDipp)Cu(CMe)] () and [(cAAC)Cu(CMe)] () have been used as catalysts for the copper(I)-catalyzed cycloaddition of benzyl azide to terminal alkynes.