Multiple C-H Bond Activations in Corannulene by a Dirhenium Complex.

The reaction of Re2 (CO)8 (μ-C6 H5 )(μ-H), 1 with corannulene (C20 H10 ) yielded the product Re2 (CO)8 (μ-H)(μ-η2 -1,2-C20 H9 ), 2 (65 % yield) containing a Re2 metalated corannulene ligand formed by loss of benzene from 1 and the activation of one of the CH bonds of the nonplanar corannulene molecule by an oxidative-addition to 1. The corannulenyl ligand has adopted a bridging η2 -σ+π coordination to the Re2 (CO)8 grouping. Compound 2 reacts with a second equivalent of 1 to yield three isomeric doubly metalated corannulene products: Re2 (CO)8 (μ-H)(μ-η2 -1,2-μ-η2 -10,11-C20 H8 )Re2 (CO)8 (μ-H), 3 (35 % yield), Re2 (CO)8 (μ-H)(μ-η2 -2,1-μ-η2 -10,11-C20 H8 )Re2 (CO)8 (μ-H), 4 (12 % yield), and Re2 (CO)8 (μ-H)(μ-η2 -1,2-μ-η2 -11,10-C20 H8 )Re2 (CO)8 (μ-H), 5 (12 % yield), by a second CH activation on a second rim double bond on the corannulene molecule. The isomers differ by the relative orientations of the coordinated Re2 (CO)8 (μ-H) groupings. All new products were characterized structurally by single crystal X-ray diffraction analysis.