Nickel(0)-Catalyzed Isomerization of an Aryne Complex:  Formation of a Dinuclear Ni(I) Complex via C−H Rather than C−F Bond Activation

The reaction of the aryne complex (PEt₃)₂Ni(η²-C₆H₂-4,5-F₂) with a catalytic amount of Ni(PEt₃)₂ results in a dinuclear Ni(I) complex from the coupling of the isomer (PEt₃)₂Ni(η²-C₆H₂-3,4-F₂), obtained via rearrangement of the aromatic C−H bonds, which demonstrates that Ni(PEt₃)₂ is kinetically capable of C−H bond activation, even in the presence of C−F bonds. The intermediate [(PEt₃)₂Ni]₂(μ-η²:η²-C₆H₂-4,5-F₂) was isolated and crystallographically characterized; the μ-η²:η²-bonding mode observed is unprecedented in aryne chemistry.