Oxidatively induced insertion of an alkylidyne unit into the tungsten tris(pyrazolyl)borate cage

The oxidation of the complexes W(CHPh)(X)(BHPz3)(Br) (X=NCMe3, N-1-adamantyl, NC6H2-2,4,6-(CH3)3, O) with Br2 was investigated. The net outcome of the reactions is insertion of the benzylidyne unit into one of the WN bonds of the tungsten tris(pyrazolyl)borate cage to afford the complexes W{[C(Ph)C3H3N2BHPz2)](X)(Br2). The crystal structures of two compounds of this type of complex with X=N-1-adamantyl and X=O have been determined by X-ray crystallography.