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.