Synthesis, characterization, and reactivity of a rhenium complex with a corannulene-based ligand

A new rhenium carbonyl complex, exo-(eta(5)-C20H17)Re(CO)(3) (3), containing a corannulene-derived ligand has been synthesized in 12% yield. The X-ray structure determination of 3 shows that the rhenium center is bound to the exo face of the bowl-shaped ligand. The reaction of 3 with PPh3 in benzene at 70 degreesC produces trans,mer-Re(H)(PPh3)(2)(CO)(3) and C20H16 (4), a bowl-shaped dibenzofulvene type molecule. The reaction of 3 with PPh3 proceeds via an eta(5)-eta(3)-eta(1) ring slip followed by a beta-hydride elimination.